An Investigation of Alternatives to Mercury Containing Products

INTRODUCTION

The Maine Department of Environmental

Protection (DEP) will issue a report on January 1,

2003 that is required under An Act to Phase Out the Availability of Mercury Added Products, PL

2001, c 620 The report will include a summary of mercury product data and a comprehensive strategy to reduce the mercury content of the products

To assist in gathering information for this report, the Maine DEP commissioned the Lowell

Center for Sustainable Production (LCSP) to conduct a study of alternatives to mercury containing products This report summarizes the findings of the LCSP investigation

The LCSP focuses on the development and promotion of environmentally sustainable production systems, ensuring healthy work environments and economically viable organizations Based at the University of Massachusetts Lowell, it collaborates closely with the Massachusetts Toxics Use Reduction Institute to advance these goals.

Reduction Institute (TURI) and the Department of Work Environment

Because of its persistent, bioaccumulative and toxic nature, the management of mercury presents a hazard to the environment that should be addressed and minimized wherever feasible.

To effectively reduce mercury exposure, it is essential to minimize its use and prevent environmental dispersion by reclaiming mercury-containing products before disposal While regulations and waste diversion strategies play a crucial role, the most efficient approach is to replace mercury-based products with alternatives that contain less hazardous materials.

The objective of this study is to accomplish the following:

• Investigate mercury product information in the public domain

• Identify priority products for investigating non-mercury alternatives.

• Identify non-mercury alternatives to the products identified.

• Conduct a qualitative evaluation of viable alternatives, including their cost and performance.

The research methodology undertaken to complete this study included:

• Telephone communication and meetings with Northeast Waste Management Officials’ Association (NEWMOA) and Maine DEP personnel were conducted to understand the information received on mercury-containing products

An internet search was performed to gather data on the flow of mercury linked to various products, serving as a benchmark for comparing the mercury product submissions from NEWMOA and DEP.

• Telephone interviews of mercury reduction experts were held to gain insight on their perspectives and to reinforce or challenge conclusions drawn by the researchers.

• An internet search and phone interviews were conducted to identify the function of mercury in products and to identify alternatives for mercury containing components and products.

• Telephone interviews were conducted with manufacturers to develop information on the alternatives, their applications, and their advantages and disadvantages.

• Interviews were held with users of medical products to understand what made a product preferable from the user’s perspective.

• A search and review of literature in the public domain was conducted to provide data on mercury products and components and their performance.

Lowell Center for Sustainable Production 7

MERCURY NOTIFICATION DATA REVIEW

Maine statutes (38 MRSA § 1661-A) restrict the sale of mercury-added products, requiring manufacturers to submit written notifications that detail the quantity and intended use of mercury Similar regulations are also in place in New Hampshire and Rhode Island.

Connecticut have passed similar mercury notification laws.

In February 2002, the Interstate Mercury

(IMERC) was formed IMERC is an umbrella organization designed to assist the eight

Northeast states in their implementation of mercury reduction laws and programs aimed at getting mercury out of consumer products, the waste stream, and the environment

Launched under the auspices of the Northeast

IMERC, coordinated by NEWMOA, has been instrumental in regional mercury reduction initiatives, supporting state environmental agencies in creating and executing targeted legislation and programs These efforts focus on manufacturer notification, product labeling, collection, and the gradual phase-out of mercury-containing products.

IMERC has compiled mercury notification data from individual states collected before February 2002 and continues to act as the central repository for all mercury notification information received since then for Maine, New Hampshire, and Rhode Island.

Connecticut IMERC has used two notification forms to collect this data:

Mercury Added Product Notification Form:

The phrase "mercury added" signifies that mercury was deliberately included in the product This form requires manufacturers to provide their contact details, along with specific information about the mercury content, including a description of the components containing mercury, the total number of these components, the quantity of mercury present, and the intended purpose of the mercury in the product.

This form requires manufacturers to provide their contact information and the total mercury content in all units sold in the United States for specific products that contain added mercury.

In December 2001, approximately 700 letters and 1,100 letters in June 2002 were sent to manufacturers to gather information on mercury-containing products IMERC reviewed these mercury notification forms for compliance with the requested data Most forms required follow-up communications with manufacturers due to missing or incorrect information Once the review process is complete, the verified data is entered into the IMERC electronic database.

In June and July of 2002, a review of the mercury notification information in the IMERC electronic database revealed data from seventy-six manufacturers reporting a total of 390 mercury-containing products Notably, mercury quantity information was accessible for ninety-eight of these products, indicating a significant amount of mercury sold across the United States Since the completion of the LCSP review, IMERC has received considerably more mercury data from manufacturers.

The following table illustrates the distribution of IMERC data for the various product types:

Lamp – cold cathode 1 Lamp – fluorescent 32

The IMERC mercury product data served as a crucial resource for this report, aiding in the prioritization process outlined in section 3 and helping to identify initial manufacturers for further inquiries Additional sources of mercury product information included consultations with manufacturers and experts, analysis of mercury product reports, and examination of relevant online data.

MERCURY PRODUCT PRIORITIZATION

A comprehensive search was undertaken to explore the range of products containing mercury The goal of this investigation was not to create an exhaustive list, but to gather essential background information on the subject.

• How is mercury being used in products?

• Why is mercury being used in products?

• How much mercury is in various products?

• What are common mercury components for various products?

• Are non-mercury alternatives available for these mercury containing products?

These questions were investigated through discussions with mercury product experts, discussions with manufacturers of mercury products, review of IMERC mercury notification results, review of responses to a May 1, 2002

State of Maine letter to mercury product manufacturers (see Appendix 4), review of published mercury product studies, and review of pertinent data available on the internet

This review highlights that mercury is commonly present in various components across numerous products, including tilt switches found in building security systems, automobile trunk lights, scanners, and robotics Additionally, mercury is also prevalent in batteries, relays, and fluorescent lamps, each utilized in a wide range of applications.

Mercury is utilized in a wide range of products due to its unique chemical and physical properties, which design engineers leverage to fulfill the requirements of various applications The following table showcases examples of products that incorporate these beneficial properties of mercury.

Product Example Property of Mercury

Electrical conductivity Position sensing products such as level sensors

Barometer Precise movement in response to air pressure differential

Thermometer Precise expansion/contraction in response to temperature change Dental amalgam Easily alloys with many metals such as gold, silver, and tin Gastrointestinal tubes Density

Fluorescent lights When energized, mercury in vapor form emits ultraviolet energy

Tilt switches utilize both the electrical conductivity and liquid at ambient conditions properties

Given the prevalence of mercury in numerous products, the research aimed to pinpoint a key selection of priority items or common components for more in-depth examination In this report, the terms "product" and "component" will be specifically defined.

Product: A product is predominately sold to the consumer in its final product state For example, a thermometer is sold to the consumer for temperature measuring purposes.

A component is primarily marketed to original equipment manufacturers (OEMs) for integration into their products For instance, a tilt switch is supplied to automobile manufacturers for inclusion in vehicles.

The following five criteria were selected as the basis for this prioritization:

1 What is the contribution of the product category to the total mercury released to the environment for all product categories?

Only limited data is available on mercury released on an individual product basis.

Total mercury emissions categorized by product type serve as a key screening criterion, indicating that product categories with higher mercury releases are prioritized for further research.

The following report was selected as a basis to support this criterion: “Substance

Flow Analysis of Mercury in Products” prepared by Barr Engineering Company for the Minnesota Pollution Control

This report offers a thorough analysis of total mercury emissions across various product categories, detailing releases into multiple environmental media, including land, air, and water Its recent publication enhances its relevance and timeliness in addressing mercury pollution.

The releases by product category from this report have been categorized as high for releases greater than 20% of total releases, medium for releases from 5% to

20% of total releases, and low for releases less than 5% of total releases.

2 What is the amount of mercury within the product?

Products with higher mercury content are prioritized for further research This information was gathered from multiple sources, including discussions with manufacturers of mercury products, an analysis of IMERC mercury notification results, a review of published studies on mercury products, and relevant online data.

3 What is the total amount of mercury reported for all sales of a specific type of product in the U.S.?

The total reported mercury amounts in U.S product sales significantly influence the prioritization of further research This data primarily stems from a review of IMERC mercury notification results, although it was only accessible for a limited number of product types during this study Additionally, as not all manufacturers had submitted their reports by that time, Table 3.3 reflects the highest reported product sales figure from a single manufacturer for each specific product.

4 Is the product addressed by existing mercury regulations?

Products containing mercury that are already regulated by the State of Maine or the federal Environmental Protection Agency (EPA) have been excluded from further study in this report This decision is based on the existing Maine statutes on mercury-added products, specifically 38 MRSA §1661 et seq., along with relevant EPA regulations.

5 Have readily available non-mercury alternatives been identified?

If non-mercury alternatives are available in the marketplace, then the product is more likely to be a priority for further

The Lowell Center for Sustainable Production conducted a comprehensive study utilizing various data sources, including consultations with mercury product experts and manufacturers, as well as an analysis of published research and relevant online information regarding mercury products.

Certain mercury-containing products, such as counterweights, jewelry, and advanced mercury alloys used in devices like converters, oscilloscopes, semiconductors, solar cells, satellites, and infrared sensors, lacked sufficient information regarding their current use, manufacturing processes, and mercury content Consequently, these products were not prioritized in this project.

As a result of applying these five criteria to mercury containing products, the following products and components were selected for further study as part of this report:

Table 3.2: Priority Products and Components

The results of applying these five criteria are summarized on the following page in Table 3.3 Priority Product Selection The shaded cells indicate the priority products selected.

The Maine DEP has compiled a summary of IMERC data as of December 2002, which reinforces the priorities established by LCSP regarding mercury levels in products and overall mercury sales in the domestic market.

Other measurement & control devices (High)

GI Tubes > 1,000 Not Available No Yes Yes

Flame sensors > 1,000 1,267,000 No Yes Yes

Barometers, hygrometer, psychrometer, hydrometer, flow meter, pyrometer

> 1,000 Not Available No Yes Yes

Permeter, barostat, oscillator, gyroscope, otoscope, sequential multiple analyser, phanotron, ignitron

Available Not Available No No No

100 – 1,000 Not Available Yes Yes No

Pressure Switch > 1,000 Not Available No Yes Yes

Temperature Switch > 1,000 Not Available No Yes Yes

Displacement/plunger relay 10 to 50, 50 to 100

Wetted reed relay 10 to 50, 50 to 100

Other mercury contact relays 0 to 5, 5 to

Not Available No Yes Yes

HID & Other Lamps HID & Other

Bulk Liquid Mercury Bulk Liquid

Not applicable Not Available Yes No No

Chlor-alkali products Chlor-alkali products (Low)

Not Available No Yes No

Not Available No No No

(Low) Misc. ppm/ppb Not Available Yes Yes No

(Low) Misc. ppm/ppb Not Available No Yes No

Film Film 0 - 5 164 No No No

Convertor, oscilloscope, semiconductors, solar cells, satellites, infrared sensors

Advanced Materials (HgCdTe, HgTe, HgSe)

Not available Not Available No No No

Cleaners, detergents, catalysts, reagents, pigments, cosmetics, other industrial/laboratory use

Compounds Misc- ellaneous ppm/ppb

Not Available No No No

Jewelry, counterweights Miscellaneous Not available Not Available No No No

The report titled "Substance Flow Analysis of Mercury in Products," prepared for the Minnesota Pollution Control Agency on August 15, 2001, highlights that certain product categories, such as film, advanced materials, and chemical compounds, were not explicitly defined It categorizes the total releases of mercury into three levels: High, indicating more than 20% of total releases; Medium, representing 5% to 20%; and Low, which is less than 5% of total releases.

2 From IMERC database, IMERC paper files, and other miscellaneous sources.

In 2001, the total mercury used in all products sold, as reported to IMERC, reflects the highest amounts disclosed by individual manufacturers for specific products It is important to note that total figures from all manufacturers have not yet been fully reported.

4 The Maine statutes restricting the sale and use of mercury-added products, 38 MRSA §1661 et seq., as well as pertinent EPA regulations were used as sources.

FINDINGS

Once the prioritization process was completed and accepted by the Maine Department of

Environmental Protection, the analysis of the priority products and components was initiated.

After conducting research and analysis of the priority products and components, the findings were prepared The findings of this study are here presented in the following format:

This section includes an overview of how the product/component operates, background information on the product/component, and typical applications of the product/component

This section identifies the non-mercury product/component available to replace the function and performance characteristics of the mercury containing product/component.

This section presents cost estimates in a range format, reflecting only the list prices accessible online or obtained through manufacturer inquiries for this study It is important to note that this range may not encompass every model or manufacturer associated with a specific technology.

Prices for a specific model can fluctuate significantly due to factors such as required options, order quantity, customer discounts, and more The provided price ranges serve solely to offer a general cost comparison across different technologies.

This section compares the effectiveness of the non-mercury alternative product/components to the mercury containing products or components.

The function of the mercury containing product/components will be considered, and the merits and shortcomings of the alternatives will be presented.

This section presents a comprehensive table detailing manufacturers of mercury-containing products and their non-mercury alternatives The table includes essential information such as the product or component name, manufacturer contact numbers, and website links for easy access.

There are two formats used in this report to present findings The priority products are covered in sections 4.2 through 4.11 utilizing the following format:

Sections 4.12 to 4.17 detail priority components using a distinct format Each non-mercury alternative is described, including its costs, advantages, disadvantages, and relevant manufacturers, reflecting their diverse applications across various products Additionally, information on both mercury and non-mercury manufacturers is included for comprehensive understanding.

Description Costs Advantages/Disadvantages Manufacturers

Costs of Using Mercury

Traditionally the cost of using mercury has been focused on the purchase price of the device.

The use of mercury involves hidden costs that are frequently overlooked, such as the risk of expensive spills, negative health impacts, liability issues, regulatory compliance expenses, and the need for specialized equipment and trained personnel to manage mercury incidents.

Tellus Institute’s report “Healthy Hospitals:

Environmental Accounting” proposes that environmental costs and benefit information can be incorporated into accounting practices to attain a more meaningful cost It considers environmental costs, which are defined as

The impacts incurred by a firm due to activities influencing environmental quality encompass both monetary and non-monetary costs These costs can be categorized into conventional expenses, potentially hidden costs, and less tangible impacts.

• Up- front: site preparation, permitting, installation

• Back- end: site closure, disposal of inventory, post- closure care

• Regula tory: training, monitoring, recordkeeping

Superfund, personal injury, property damage

• Employee safety and health compensation

The same report provides a case study of

Kaiser Permanente, the largest non-profit Health Maintenance Organization (HMO) in the U.S., has implemented mercury minimization efforts by evaluating the costs associated with mercury thermometers and sphygmomanometers Although aneroid sphygmomanometers have a higher initial purchase price, their lifecycle costs significantly lower total expenses, making them about one-third the cost of mercury units A 2002 LCSP study revealed that the purchase costs for mercury and aneroid sphygmomanometers are now comparable, further enhancing the cost-effectiveness of non-mercury alternatives.

Kaiser’s mercury minimization initiatives have significantly reduced costs by lowering the frequency of spills, exposure incidents, and liability, along with minimizing the need for staff toxic training, as shown in Table 4.2 Their estimates indicate that for every dollar spent on spill response, there may be an additional $1.75 incurred for training, fines, and exposure treatment (Tellus Institute, 2000) While cleanup costs are not extensively documented, various reports found online shed light on the financial implications of mercury spills, summarized in Appendix 2.

The LCSP study highlights key costs associated with both mercury and non-mercury products, which should be taken into account for a comprehensive evaluation of these items, despite not providing complete life cycle cost data.

Table 4.2 : Kaiser Permanente Case Study

Sources of cost avoidance estimate

The expenses associated with a mercury spill kit and the spill response services provided by Kaiser Permanente's contractor are well-documented By analyzing these costs alongside the average annual incidents of spills from broken devices, it becomes possible to estimate the potential savings from preventing such incidents.

Use of mercury-containing devices necessitates staff spill/exposure training.

Proper staff training, diligent handling, and effective spill response procedures are essential when managing mercury-containing devices, as they can lead to potential fines during facility inspections or spill incidents The estimated costs associated with mercury-related penalties are calculated by multiplying representative statutory and regulatory fines by the likelihood of a fine being imposed for specific violations.

The treatment of mercury exposure presents a probabilistic cost, as even with stringent safety measures, some mercury exposures from broken devices are likely to occur within the Kaiser system The financial implications are significant, with the expected annual cost for long-term treatment of a single pediatric exposure case exceeding $100,000, coupled with the probability of such incidents happening each year Additionally, there are potential soft savings to consider in managing these risks effectively.

(environmental staff were aware of these costs, but they were not quantified)

“Soft cost” savings were not estimated, but could, include: environmental contamination from mercury release, subsequent health impact, and negative media attention.

Sphygmomanometers

Blood pressure, a key indicator of cardiovascular performance, is produced by the heart's activity and the blood vessel system Consequently, fluctuations in blood pressure levels serve as a reliable measure of both cardiovascular function and overall health.

Most blood pressure monitors utilize an air-filled cuff to momentarily restrict blood flow in the artery As the cuff deflates, specific techniques are employed to accurately measure blood pressure The two primary methods for obtaining these measurements are the auscultatory technique and another common approach.

(listening for characteristic blood flow sounds) or oscillometric technique (using a pressure transducer).

When discussing blood pressure devices, two key factors are crucial: the method of sensing blood pressure—whether through the ear or a pressure transducer—and the type of gauge used to display the pressure value, such as a mercury column, dial gauge, or digital display The mercury column remains the traditional standard for indicating blood pressure levels.

In clinical blood pressure measurement, two primary alternatives to mercury sphygmomanometers are aneroid sphygmomanometers and low-end professional electronic monitors Additionally, various non-mercury options such as home monitors, ambulatory blood pressure monitors, and high-end vital signs monitors exist; however, these are not typically regarded as direct substitutes for traditional mercury devices.

Auscultatory Sphygmomanometers (mercury and aneroid)

Mercury and aneroid sphygmomanometers rely on the auscultatory technique, in which a clinician determines systolic and diastolic blood pressures (SBP and DBP) by listening for

Korotkoff sounds are crucial auditory indicators that reveal various stages of blood flow during the deflation of a blood pressure cuff Clinicians utilize these sounds to accurately measure pressure at specific points, employing either a mercury column or an aneroid gauge This method is favored for its affordability and ease of use, making it the most commonly adopted technology in blood pressure assessment.

The mercury sphygmomanometer utilizes a column of mercury to display blood pressure readings, effectively measuring pressure from 0 to 300 mmHg Its liquid state allows for precise expansion and contraction, making it an ideal choice for accurate pressure indication.

An aneroid gauge features a dial that measures pressure from 0 to 300 mmHg and contains a brass corrugated bellows It operates through a shaft connecting two perpendicular pins; one pin rests on the bellows while the other interacts with a concave triangle linked to a dial pointer A hair spring ensures the pointer resets to zero when pressure is released The gauge is attached to a blood pressure cuff on the patient's arm, and as cuff pressure increases, the bellows expand, causing the pins to move and the pointer to indicate the pressure reading accurately.

Welch Allyn has launched the Dura Shock aneroid sphygmomanometer, featuring an innovative internal design that makes it lighter, more affordable, and significantly more shock-resistant than traditional models Further research is needed to explore the benefits of this new design.

The oscillometric blood pressure monitor utilizes a pressure sensor and microprocessor instead of traditional methods like the ear and simple gauge As the cuff deflates, the pressure sensor sends an electrical signal that reflects the artery's distention This signal is then processed by the microprocessor to determine systolic and diastolic blood pressure (SBP and DBP).

DBP) using empirically derived algorithms.

Manufacturers spend considerable effort validating their algorithms for accuracy.

Modern blood pressure monitors not only measure systolic and diastolic blood pressure (SBP and DBP) but also offer detailed insights into blood pressure patterns, enhancing diagnostic capabilities Although these advanced devices are less common than traditional auscultatory monitors due to their higher cost and complexity, prices have significantly decreased in recent years As a result, manufacturers are increasingly promoting these monitors to hospitals for their comprehensive data offerings.

Electronic equipment using the oscillometric technique is common in two types of equipment:

The mid-range blood pressure monitor is engineered to rival traditional auscultatory devices In recent years, numerous companies have introduced this type of monitor, and as prices have dropped, its adoption has become increasingly common.

Vital signs monitors are essential devices commonly used in hospitals to simultaneously track multiple critical parameters such as temperature, blood pressure, heart rate, and blood oxygen levels, which are crucial for patient care These monitors feature an electronic box containing various modules, each dedicated to measuring a specific vital sign, ensuring comprehensive patient monitoring for improved outcomes.

Various device manufacturers offer alternatives to mercury sphygmomanometers While these devices are commonly found in hospitals, they do not serve as direct one-for-one replacements for traditional mercury models.

Most manufacturers of auscultatory devices offer both mercury and aneroid sphygmomanometers.

A sampling of prices for mercury and aneroid devices revealed essentially no difference between the two, as shown in the following table.

Table 4.3 Cost of Comparable Mercury and

Welch Allyn Mercury Not available 2 Pocket unit DuraShock 3 aneroid

1 These prices were obtained by contacting each manufacturer and/or their websites and requesting pricing on comparable mercury and aneroid units.

2 No comparable unit because Hg column must be rigidly mounted in perfectly vertical position; incompatible with hand-held or portable units.

3 The DuraShock is a new product for Welch Allyn that is more resilient than a traditional aneroid This design also results in a significantly lower cost.

Oscillometric blood pressure monitors are considerably higher in price, as shown in the following table

Table 4.4 Cost of Oscillometric Blood Pressure

Manufactur er & Style List or

When evaluating blood pressure devices, clinicians and hospital systems must consider several key factors, including cost, accuracy, ease of use, maintenance and calibration requirements, and environmental impact It's essential to weigh the advantages and disadvantages of these devices to ensure optimal patient care and resource management.

1 The method of pressure sensing; i.e auscultatory (listening to sounds) versus oscillometric (using pressure transducers)

2 The pressure readout mechanism; i.e mercury manometer, aneroid gauge, or microprocessor with digital display.

Auscultatory devices, such as mercury and aneroid sphygmomanometers, depend on the user's auditory skills to measure systolic and diastolic blood pressure, which can lead to measurement errors due to varying levels of auditory acuity In contrast, oscillometric monitors are less reliant on operator technique and provide a wider range of baseline data, including mean arterial pressure (MAP) and pulse rate Additionally, some oscillometric monitors offer the option to add modules for monitoring other vital signs.

Esophageal Dilators (Bougies) and Gastrointestinal Tubes

An esophageal dilator, also called a bougie, is a long, weighted flexible tube that is passed down a patient’s esophagus to dilate a narrowed area.

Historically, mercury was widely utilized in bougies due to its density and liquid form, which allowed it to function as a flexible weight that facilitated the insertion of the tube into the esophagus This property enabled the mercury to conform to the esophageal shape and apply the necessary pressure to expand narrowed areas These mercury-filled devices are encased in a durable latex outer coating and typically contain around two pounds of mercury Esophageal dilators are commonly used in fields such as thoracic surgery, otolaryngology, and medical procedure units.

The alternatives to mercury bougies use a tungsten gel to provide the flexible weight.

Tungsten, being a solid at room temperature, is utilized in devices as a powder suspended in gel This formulation enables the dilator to flex and adapt to the esophagus's shape, providing a density comparable to mercury and effectively applying the necessary pressure to expand the constricted area of the esophagus.

Mercury bougies are no longer widely available.

Among the three identified manufacturers, only one continues to provide mercury bougies, priced at $3,395 for a complete set Replacement tungsten gel bougies are available, ranging from $3,000 to $4,400 Notably, the manufacturer offering the higher price of $4,400 also provides a 10% discount and a complimentary take-back option for mercury bougies.

Bougies have a limited lifespan due to the risk of degradation of their outer rubber casing Once they reach the end of their useful life, mercury bougies must be disposed of as hazardous materials The handling or use of mercury-containing esophageal dilators poses significant risks, as they can rupture, leading to potential hazards for the environment, patients, and healthcare employees.

Report (MDR) system includes reports of bougies rupturing and leaving mercury inside the patient as well as in the room Examples of

MDRs for ruptured bougies are included in

The tungsten bougie is considered to be a safer, more environmentally benign alternative.

Tungsten gel-filled bougies offer performance comparable to mercury-filled bougies, requiring no changes in technique for use At the end of their lifespan, these tungsten bougies can be safely disposed of in the trash They come with either a silicone or PVC covering, with the silicone option providing a non-slip surface when dry and a slippery surface when wet, enhancing ease of handling Due to environmental concerns regarding dioxin formation during the incineration of PVC waste, many healthcare facilities are transitioning away from using PVC coverings.

The following are manufacturers of non-mercury and mercury esophageal dilators:

Bougie 800-558-6408 www.medovatio ns.com

(Maloney style and Hurst style bougies are weighted with tungsten gel)

(Maloney style and Hurst style bougies are tungsten filled)

Tungsten filled bougies are increasingly recognized as effective alternatives to mercury-containing bougies, according to phone interviews with manufacturers and medical practitioners A seasoned practitioner from a hospital in the northwest suburbs of Boston noted that her facility had transitioned from mercury bougies to tungsten filled options years ago, and she reported that the non-mercury devices have consistently performed well.

Another family of tubes, including Miller Abbott,

Blakemore, and Cantor tubes, are used for addressing intestinal obstructions Historically these tubes used mercury as a flexible weight to guide the tube into place through gravity

This product category indicates a data gap in the report, as research shows that these devices have fallen out of widespread use No manufacturers of mercury-containing devices were identified, although unweighted tubes are still available It is believed that some customers may add their own mercury, despite manufacturers not supplying it.

Two manufacturers have presented their products as effective alternatives for specific applications Andersen provides both unweighted and tungsten-weighted tubes, which they position as substitutes for the Miller-Abbott and Cantor tubes.

Rusch’s Product Manager suggested that practitioners can add sterile water to the Cantor tube, as a weight to help move the tube.

A cost comparison is not relevant since mercury products were not located However, the cost of the non-mercury Miller Abbott and Cantor tubes were approximately $300 to $400.

A manufacturer has indicated that sterile water can serve as a substitute for mercury as a weight for the Cantor tube; however, this alternative leads to a slower passage of the tube, resulting in extended medical procedure times.

The following are manufacturers of gastrointestinal tubes for which the buyer must provide the weighted liquid:

Rusch Cantor Tubes 800-524-7722 www.myrusch. com

Recent research indicates that gastrointestinal tubes are becoming less common in hospital settings There is uncertainty regarding the continued use of mercury in these products, especially in areas where gastrointestinal tubes are still in use Additionally, it remains to be seen if there are acceptable alternative practices or products available.

In 1995, Dartmouth Hitchcock Medical Center successfully replaced mercury in Miller Abbott Tubes with water and contrast media, addressing initial concerns about potential delays in procedures due to the lighter weight of water Notably, the Safety and Environmental Programs office received no complaints from clinicians regarding the change Additionally, nursing and housekeeping staff expressed satisfaction with the elimination of mercury, as they were previously responsible for managing mercury spills.

Manometers

Manometers are essential instruments for measuring the pressure of air, gas, and water, with mercury providing precise readings that can be calibrated accurately They find applications in various fields, including laboratories, the dairy industry during the milking process, and for calibrating outboard motors and motorcycle carburetors Additionally, HVAC contractors utilize manometers for testing, balancing, and servicing equipment, highlighting their versatility and importance in multiple industries.

There are three main alternatives to a mercury manometer: the needle/bourdon gauge, the aneroid manometer, and the digital manometer The needle/bourdon gauge measures pressure using a needle indicator in a vacuum, while the aneroid manometer functions similarly In contrast, the digital manometer utilizes a digital computer with programmed memory and gauges for precise pressure measurement.

Digital manometers are versatile instruments designed for a variety of applications, with prices typically ranging from $100 to $700 based on their specific use In contrast, needle and bourdon gauges are generally more affordable, costing between $50 and $200, depending on the manufacturer and intended application.

Calibration is essential for digital manometers, mercury manometers, and needle/bourdon gauges to ensure accurate readings When properly calibrated, digital manometers can offer greater precision compared to mercury manometers.

The following are manufacturers of non-mercury manometers.

Instruments Digital manometer 781-890-7440 www.extech.com

Instruments Digital manometer, Needle/ bourdon gauge

Alternatives to mercury manometers are proving to be cost-effective, reliable, and widely adopted across the United States A notable example is a project in Wisconsin, funded by a $40,000 EPA grant, where dairy equipment service providers replaced over 100 mercury manometers on local dairy farms with non-mercury options Similarly, Maine has successfully replaced 25 mercury manometers from milking machines in dairy barns, showcasing the growing trend towards safer, non-toxic alternatives in the dairy industry.

Thermometers (non-fever)

Basal metabolic temperature, the lowest normal body temperature upon waking, reflects an individual's basal body metabolism Daily fluctuations in this temperature reveal the body's cyclical changes, making it a valuable indicator for assessing ovulation.

A basal thermometer, designed for greater sensitivity than a standard fever thermometer, measures baseline temperature with precision Unlike conventional thermometers that have a smallest division of 0.2 degrees, basal thermometers can detect changes as small as 0.1 degrees, making them ideal for tracking subtle fluctuations in body temperature.

Mercury basal thermometers are similar in function to mercury fever thermometers A column of mercury within a glass tube expands with increasing temperature and registers a reading at the peak temperature.

Alternatives to basal thermometers are galinstan- in-glass (liquid in a glass tube) and compact digital thermometers.

Geratherm offers Galinstan basal thermometers, which feature a silvery liquid contained in a glass tube, similar to traditional mercury thermometers This unique liquid, composed of gallium, indium, and tin, expands with temperature changes to deliver accurate readings, making it comparable to Geratherm fever thermometers.

Battery-powered digital basal thermometers are the most common option for basal thermometers These are similar in appearance and function to digital fever thermometers.

Basal thermometers are fairly inexpensive and technologies are readily available for under $15.

The cost of devices is historically lowest for mercury basal thermometers, mid-range for

Geratherm, and highest for digital devices.

A data gap exists for the cost of mercury basal thermometers as our research was unable to easily identify a current manufacturer Becton

Dickenson, a prominent medical manufacturer, has ceased the production of mercury basal thermometers Additionally, local pharmacies have removed these thermometers from their shelves, though anecdotal evidence indicates that they may still be found in other regions.

According to one manufacturer, their list price for the Geratherm basal thermometer is $7.69-

$7.99 Another manufacturer reported that the average list price for its digital basal thermometer is $12

Mercury basal thermometers are favored for their affordability and familiarity; however, they come with several drawbacks These include a lengthy wait time of 3-5 minutes to reach peak temperature, the need to shake down the thermometer between readings, challenges in accurately reading the mercury column, a fragile glass design, and limited availability in the market.

The Geratherm liquid-in-glass thermometer functions similarly to traditional mercury thermometers, featuring a glass tube filled with a silvery liquid that rises with temperature increases This thermometer is more affordable than digital alternatives, making it a cost-effective choice However, Galinstan thermometers, which use a gallium-indium-tin mixture, present several drawbacks, including unclear toxicity, potential confusion with mercury, fragility of the glass, and a slightly larger size compared to mercury basal thermometers.

Digital basal thermometers are a popular alternative to mercury thermometers due to their quick reading time of about one minute, compared to approximately four minutes for mercury devices They offer convenient features such as beep alerts when the peak temperature is reached and a memory function to recall the last reading However, a notable downside is their reliance on batteries, which necessitates proper recycling and disposal once they are no longer functional Additionally, digital basal thermometers tend to be more expensive than both mercury thermometers and Geratherm thermometers.

The following are manufacturers of basal thermometers:

Becton Dickinson Digital basal thermometer 201-847-6800 http://www.bd.com Mabis

Digital basal thermometer 800-231-3434 http://www.omronh ealthcare.com R.G Medical

Geratherm basal thermometer (Galinstan liquid-in-glass thermometer)

Based on discussions with manufacturers and visits to local pharmacies, it appears that suitable alternatives are readily available for mercury basal thermometers.

Non-fever thermometers play a crucial role in industrial, laboratory, and commercial settings, particularly in food preparation and storage environments like freezers and lab refrigerators Adhering to specific laboratory protocols and food safety standards necessitates the use of high-quality thermometers to ensure accurate temperature monitoring.

The colored-liquid glass thermometer, often referred to as a liquid thermometer, serves as a popular alternative to mercury thermometers Similar in design to mercury thermometers, it features a cylindrical tube filled with a liquid that expands and contracts with temperature changes Commonly used liquids include dyed organic substances like alcohol, kerosene, and citrus-based solvents in colors such as blue, red, or green Some brands promote their liquid thermometers as non-toxic or environmentally friendly Additionally, digital, bi-metal, and infrared thermometers are viable substitutes for mercury thermometers, applicable in many of the same contexts.

The costs of a thermometer can vary based upon the requirements of a particular application.

The following table illustrates these cost differences.

Bi-metal $13 - $138 Digital $14 - $20 Liquid filled $2 - $28 Industrial Infrared $92 - 270

Digital $20 - $100 Liquid filled $20 – $60 Infrared $92 - $270 Freezer/

Digital and infrared thermometers offer high accuracy and ease of reading, making them essential tools in various applications While infrared thermometers tend to be more expensive than digital ones, their unique capabilities justify the cost in specific situations Regardless of the type—mercury, digital, bi-metal, or organic liquid—all thermometers require annual re-calibration to ensure precision, as mechanical strains in the glass can gradually affect the bulb's volume.

A disadvantage of all liquid thermometers is the possibility of column separation When a separated column occurs, the thermometer cannot be used until the column is rejoined and recalibrated

Manufacturers' evidence shows that many alternatives to mercury thermometers are equally effective and reliable when calibrated regularly A significant obstacle to adopting these alternatives is the entrenched perception of mercury thermometers as the "standard" for temperature measurement.

The following are manufacturers of alternatives to mercury thermometers.

Liquid filled, Digital thermometer www.icllabs.com

Digital, Bi-metal thermometer Taylor Liquid filled,

It is apparent that there are many alternatives to mercury thermometers that are cost effective and acceptable However, a Food and Drug

Administration procedure for food processing was identified that requires at least one mercury- in-glass thermometer for each retort This requirement is outlined in the Code of Federal

Regulations under: 21 CFR Ch 1 Part 113 –

Thermally Processed Low-acid Foods Packaged in Hermetically Sealed Containers.

An example of a successful mercury thermometer replacement program is the

The University of Vermont's "Mercury Thermometer Swap" program successfully replaced over 1,400 mercury thermometers with safer non-mercury alternatives, primarily in the chemistry department's laboratories.

Barometers

Barometers measure atmospheric pressure using a long cylindrical tube filled with mercury As atmospheric pressure changes, it displaces the mercury; a rising mercury level signifies increasing air pressure, while a falling level indicates decreasing air pressure.

The aneroid barometer is a compact device featuring an evacuated metal diaphragm that mechanically connects to an indicating needle, reflecting changes in atmospheric pressure as the diaphragm compresses or expands In contrast, the digital barometer utilizes sensors with electrical properties that vary with pressure changes, offering accuracy comparable to traditional and aneroid models These sensors feed data to electronic circuitry, which translates the output into a digital display Additionally, a water barometer operates similarly to a mercury barometer, where fluctuations in air pressure cause water levels to rise or fall; a low water level signifies high pressure and fair weather, while rising water levels indicate decreasing pressure.

The digital barometer can cost between $50 -

Digital barometers typically cost around $300, influenced by the manufacturer and additional features In contrast, mercury and aneroid barometers are often sought after as collector's items, leading to significantly higher prices that range from $100 to over $1000.

Aneroid barometers, in use for nearly 200 years, offer accuracy comparable to traditional mercury barometers Similarly, digital barometers, which are programmable, also match the precision of mercury models, making them reliable options for measuring atmospheric pressure.

The following are manufacturers of alternatives to mercury barometers.

Manufacturer Name Product Phone Number/

Howard Miller Aneroid www.howardmiller.c barometer om

410-263-6700 www.weems- plath.com Bacharach Digital barometer 724-334-5000/1-800-

Kestrel Digital barometer 610-447-1555 www.nkhome.com

The aneroid and digital barometers are cost effective, in use, and acceptable alternatives to the mercury barometer.

Psychrometers/Hygrometers

A hygrometer is a device that measures the moisture levels in the air or gases, with the dry and wet-bulb psychrometer being the most common type This instrument consists of two mercury thermometers: one with a wet base and the other with a dry base As water evaporates from the wet base, it absorbs heat, resulting in a lower temperature reading on that thermometer.

Using a calculation table, the reading from the dry thermometer and the reading drop from the wet thermometer are used to determine the relative humidity

The sling psychrometer is an effective tool for measuring relative humidity, utilizing both digital and alcohol-based methods It consists of a thermometer housed in a swiveling mechanism, which is swung rapidly to obtain precise humidity readings.

Psychrometers function the same as a hygrometers, however the names are different due to the applications for which they are used.

For example, the hygrometer is used to monitor the moisture in the storage area for cigar tobacco used by manufacturers and cigar aficionados.

Atmospheric scientists and weather enthusiasts use the psychrometer to monitor outdoor humidity and moisture content

Spirit-filled thermometers serve as effective substitutes for mercury thermometers in psychrometers, delivering comparable accuracy Additionally, digital hygrometers, which utilize electronic sensors and digital programming to assess air humidity, are also viable alternatives Both spirit-filled and digital hygrometers are affordable, widely accessible, and commonly utilized in various applications.

The spirit-filled sling psychrometer and hygrometer are comparably priced to their mercury counterparts, while the digital psychrometer tends to be pricier than the spirit-filled variant In contrast, the digital hygrometer is generally more affordable than the spirit-filled model, with prices ranging from $15 to $60.

The digital hygrometer and digital psychrometer provide much more accurate results when properly calibrated because the possibility of human error is eliminated

The following are manufacturers of alternatives to mercury psychrometers and hydrometers:

Bacharach Spirit filled psychrometers 1-800-736-4666 www.bacharach- inc.com

800-227-0729 www.testo.com Miller Weber Digital hygrometer

Mannix Spirit filled psychrometers 516-887-7979 www.mannix- inst.com Tramex Digital hygrometer 353-1-282 3688 www.tramexltd.c om

The spirit filled psychrometers and digital hydrometers appear to be acceptable, cost effective alternatives to mercury filled devices.

Hydrometers

A hydrometer is a device that measures the density or specific gravity of a liquid.Hydrometers are calibrated based upon the specific gravity of water at 60°C being 1.000.

Liquids with a higher density than water exhibit a greater specific gravity, whereas those with a lower density show a reduced specific gravity A hydrometer serves various purposes across multiple industries, including petroleum and dairy, and is also popular among hobbyists in wine and beer production.

A spirit-filled hydrometer serves as an effective alternative to traditional mercury hydrometers, offering customization for specific applications To ensure optimal performance, it is essential to consult the manufacturer for guidance on selecting the most suitable hydrometer for your needs.

The cost of a mercury hydrometer ranges from

$12 to $30, or about $2 less on average than a spirit filled hydrometer.

The accuracy of a spirit filled hydrometer is considered to be comparable to a mercury hydrometer

The following are manufacturers of alternatives to mercury hydrometers:

Miller Weber Alcohol/spirit filled hydrometer

Alcohol/spirit filled hydrometer www.icllabs.co m

The spirit filled hydrometer is cost effective, in use, and an acceptable alternative to the mercury hydrometer.

Flow meters

Flow meters play a crucial role in various industries by accurately measuring the flow of gases, water, air, and steam These instruments are essential in applications such as water treatment facilities, sewage treatment plants, power stations, and numerous other industrial sectors.

Manufacturers have confirmed that new flow meters are produced without mercury; however, many older models still in operation contain this hazardous substance Alternatives to mercury-based flow meters include digital and ball actuated options, which provide safer and more environmentally friendly solutions.

The cost of flow meters varies based on their specific applications, with some models being custom-designed, which can lead to higher prices Manufacturers often refrain from providing a price range, as they believe it could be misleading.

The following are manufacturers of alternatives to mercury containing flow meters:

Digital and ball actuated flow meters

John C Ernst Digital and ball actuated flow meters

Lake Monitors Digital and ball actuated flow meters

1-800-850-6110 www.lakemoni tors.comUniversal Digital and 248-542-9635

Flow Monitors ball actuated flow meters www.flowmete rs.com

419-756-1746 www.digiflows ys.com Primary Flow

Signal, Inc Digital and ball actuated flow meters

It appears that mercury flow meters are no longer being manufactured, and alternatives to older mercury flow meters are in use, cost effective, and acceptable.

Pyrometers

Pyrometers are essential tools for measuring the temperature of extremely hot materials, particularly in foundry applications Currently, no manufacturers offer mercury pyrometers, although some existing models still utilize mercury in their temperature-sensing mechanisms.

There are two main types of pyrometers for measuring temperature: optical and digital An optical pyrometer measures temperature by detecting the color of incandescence, with objects glowing red at around 700°C and transitioning from red to orange to white as temperature increases, indicating higher energy emissions This device uses an optical system and a lamp filament to match brightness with the target, providing an accurate temperature reading In contrast, digital pyrometers utilize a thermocouple and display the temperature on a digital screen, offering a straightforward and modern approach to temperature measurement.

The cost of an optical pyrometer is in the range of $3000 The cost of a digital pyrometer is less than an optical pyrometer, and can cost between

The cost of a mercury pyrometer remains undetermined, as no manufacturers could be identified, and alternative manufacturers declined to provide pricing estimates for this specific device Prices for similar instruments typically range from $180 to $300, depending on the manufacturer.

Optical pyrometers are highly accurate instruments designed for measuring extreme temperatures, making them ideal for demanding applications While digital pyrometers offer reliable and functional temperature readings, they do not match the accuracy of optical pyrometers at elevated temperature ranges.

The following are manufacturers of alternatives to mercury pyrometers:

MIFCO Digital pyrometer 217-446-0941 www.mifco.co m Spectrodyne Optical/ pyrometers 215-977-7780 www.spectrod yne.com Precision

The mercury pyrometer is no longer in production, although it may still be utilized in certain areas As alternatives, digital and optical pyrometers offer reliable technology for temperature measurement.

Thermostats (industrial and manufacturing)

Industrial thermostats provide temperature control in manufacturing and industrial settings.

The mercury thermostat operates through a mercury switch that controls the heating and cooling systems This switch is integral to an electric current relay, utilizing the flow of electricity to turn the heating or cooling device on and off as the mercury tilts within the switch.

Digital electronic thermostats are designed for industrial applications, providing precise temperature control They utilize a thermistor, a resistor that alters its electrical resistance in response to temperature changes, to measure temperature The microcontroller within the thermostat interprets this resistance and converts it into an accurate temperature reading.

Manufacturers cannot offer specific price quotes for industrial thermostats, as these devices are typically customized to fit the unique needs of each application Consequently, pricing is determined on an application-specific basis To avoid misleading potential customers, manufacturers refrain from providing a price range based on previously manufactured thermostats tailored for specific uses.

Digital thermostats have limits that should be researched by the buyer to determine the type of thermostat best suited for an industrial purpose.

Many industrial thermostats are needed to regulate higher temperatures than household thermostats Industrial thermostats are created to be more durable and withstand higher temperatures and harsher environments.

Manufacturers of digital thermostats for light industrial use indicate that these devices may not be suitable for high-demand applications In extreme environmental conditions or in areas susceptible to explosions or fire, digital thermostats may underperform compared to traditional mercury thermostats.

The following are manufacturers of industrial thermostats:

Chromalox Thermostats 412-967-3800 http://www.mych romalox.com/ Honeywell

International Thermostats 612-951-1000 www.honeywell. com

It appears that no functional alternatives to mercury thermostats for industrial settings with harsh environmental conditions are available.

Float Switches

Float switches are essential devices used for liquid monitoring and control, categorized into two types: one type is housed in a buoyant float that activates based on changing liquid levels, while the other remains stationary and responds to the presence or absence of liquid These switches are commonly employed in tanks, wells, chambers, and other containers to trigger alarm and control circuits They are versatile and can monitor a variety of liquids, including water, sewage, wet sludge, oil, chemicals, grease, and liquid nitrogen.

A float switch is a versatile component essential for numerous products and applications, including bilge pumps and automobiles It can be integrated into existing products or purchased as a standalone component for specific customer applications, such as in waste treatment plants Many of these applications may already utilize non-mercury float switches, highlighting their widespread use and adaptability.

• Pump control: bilge, sump, utility, shower, effluent, waste, lubrication, etc.

• Equipment Control: magnetic valve, cooling equipment, motors, etc

• Alarm/Outputs: programmable logic controllers, distributed control systems, supervisory control and data acquisition, etc.

• Industrial/manufacturing: processing liquids, waste treatment, air conditioners, semiconductor manufacturing, automatic plating machinery, etc.

• Residential: sump pumps, septic tanks, hot water heaters, automatic plumbing fixtures, etc.

• Marine: bilge pumps, shower pumps, ocean liner sewage disposal, balance tank on ships, etc.

• Automobile: fuel tank, windshield wash reservoir, etc.

• Municipal: pumping stations, waste water treatment, sewage plants, etc.

• Commercial: boilers, vending machines, electrical equipment such as liquid insulated transformers, etc.

• Miscellaneous: food processing, irrigation systems, petrochemical processing, laundry tray, food warmers, steam cookers, mineral processing, hydraulic equipment, water filters, pharmaceutical processes, food processing, power stations, etc.

When selecting a float switch for a specific application, various design parameters play a crucial role in determining the appropriate specifications The diversity in float switch designs and options across manufacturers highlights the importance of understanding these parameters Key factors influence technology choice, manufacturer selection, product model, available options, and overall cost Here is a summary of the critical design parameters to consider.

• Switch points: number of control points, number of alarm points, field adjustable points, etc.

• Level detection: point level, continuous level

• Liquid environment: viscosity, conductivity, foam, bubbles, turbulence, contaminants, debris, etc.

• Mounting: side, bottom, or top of enclosure, free standing/suspended cable, pipe mount, stem mount, etc.

• Output contact rating: inductive load, resistive load, current, voltage, power, etc.

• Buoyancy: ball, counterweight, specific gravity, etc.

• Life expectancy: switch, controlled equipment, etc.

• Regulatory approval: Underwriters Laboratories, Canadian Standards Association, etc.

• Operating parameters: differential between control/alarm points, angle of operation, etc.

• Environmental conditions: temperature, pressure, explosiveness, shock, vibration, corrosiveness, moving equipment, etc.

• Input power requirements: 115 Volts AC,

230 Volts AC, 24 Volts DC, 12 Volts DC, other

• Switch: number of poles, number of throws, normally open, normally closed, relay, etc.

• Other parameters: signal time delay (to compensate for wave action), float switch enclosure material, intrinsically safe, cleaning requirements, space available for operation, etc.

A mercury float switch is housed in a buoyant float and activates based on liquid level changes It features a small tube with electrical contacts; as the float rises, mercury collects at the bottom, completing the circuit When the float tilts back, the circuit breaks This mechanism is akin to that of a mercury tilt switch, with reported mercury content for these float switches exceeding 1,000 mg per switch, according to IMERC.

The price of a mercury float switch ranges from $15 to $150, varying based on the type and application requirements Two manufacturers offer both mercury and non-mercury float switches with identical functionality, charging the same price for each However, one manufacturer provides a non-mercury mechanical float switch at a lower cost compared to its mercury counterpart, despite offering the same features.

One manufacturer charged more for a metallic ball float switch than for a mercury float switch with comparable functionality

The mercury float switch is known for its high reliability and extended operational life due to its minimal components and absence of arcing With over one million cycles of life-cycle testing, it effectively manages high inductive loads while ensuring quiet operation and eliminating contact bounce Additionally, its hermetically sealed design offers enhanced protection against environmental factors such as dust and moisture Notably, the switch can utilize a single float for both on and off functions, making it a versatile choice for various applications.

The mercury float switch needs sufficient swing space for effective operation; however, in confined areas like windshield washer reservoirs, a magnet/reed float switch is a better option Due to the presence of mercury, these switches are increasingly avoided in various applications, particularly in the food and beverage sector.

The following are manufacturers of mercury float switches.

Manufacturer Name Product Phone Number &

Contegra Inc FS 96 651-905-0900 www.contegra.com

978-281-0440 www.rule- industries.com Mercury

FG Series 888-525-7300 www.levelandflow.c om

A mechanical float switch is housed in a buoyant float assembly and operates by responding to changes in liquid levels It typically uses a snap switch or micro-switch, activated through various mechanisms The most prevalent method involves a lever arm that is triggered by a metallic rolling ball, which shifts position due to gravity and the movement of the buoyant float housing.

The price range for mechanical float switches typically falls between $10 and $150, influenced by specific product or application needs Notably, two manufacturers offer both mercury and non-mercury float switches that serve the same purpose, with identical pricing for each type However, one manufacturer stands out by offering a non-mercury mechanical float switch at a lower cost than its mercury counterpart, while maintaining the same functionality.

The mechanical float switch is known for its high reliability and extended operational life, capable of handling substantial inductive loads Designed to endure over one million cycles, it features a hermetically sealed construction that offers enhanced protection against environmental factors such as dust and moisture Additionally, it utilizes a single float for both on and off functions, making it an efficient choice for various applications.

Mechanical float switches usually require a swing area for effective operation, but those utilizing magnets within a vertical stem can activate the micro-switch without needing this space.

The following are manufacturers of mechanical float switches:

Series 651-905-0900 www.contegra.com Dwyer

Jabsco FS20 949-609-5106 www.jabsco.com

Scientific Technologies Inc.: 888-525-7300 www.kari-finn.fi

800-621-8806 www.us.water.danfos s.com

Nivofloat and NivoMag MK-200 Series

FT, FTN, and MLS Series

Permanent magnets are integrated into the float housing, allowing them to move vertically along the tubing or stem Reed switches, also embedded in the stem, are activated by these magnets at specific levels, serving control or alarm functions.

The magnetic dry reed float switch cost is approximately $6 to $500 depending on product or application requirements.

The magnetic dry reed switch is ideal for use in small or narrow enclosures The magnetic dry reed switch has a long operational life.

The magnetic dry reed switch is not suitable for high inductive loads due to its low contact rating It requires a clean environment for optimal performance, as debris on the stem can hinder its functionality Additionally, exposure to high voltage sources can lead to the contacts being welded together, compromising the switch's effectiveness.

The following are manufacturers of magnetic dry reed switches:

Numerous models 888-340-8820 www.actsensors. com

Aggressive Systems, Inc AOE model 248-477-5300 www.aggressives ystems.com Barksdale, Inc BLS Series 800-835-1060 www.barksdale.c om

Clark Reliance Corporation Jerguson Gage and Valve Division

RSF Series 619-210-1600 www.crydom.co. uk

Dwyer Instruments, Inc F7 Series 219-879-8000 www.dwyer- inst.com

Flowline Liquid Intelligence Numerous models 562-598-3015 www.flowline.co m

Innovative Components LS and SM

Kobold Model N 800-998-1020 www.kobold.co m

905-840-7106 www.process- controls.com/KT ech

FL, SLS, and TLS Series

The optical float switch employs optical technology to sense the presence or absence of liquid in contrast to air It features a compact infrared LED paired with a phototransistor light receiver, which effectively identifies the presence of liquid.

The cost of an optical float switch is approximately $120 to $400 depending on product or application requirements.

The optical sensor is unaffected by liquid color or density The optical float switch has very slight hysteresis, high repeatability, and is highly chemical resistant.

The optical float switch has a higher price range than other float switch technologies.

The following are manufacturers of optical float switches:

Float Switch 954-600-1962 http://comconnecti on.tripod.com

OLS Series 219-879-8000 www.dwyer- inst.com

Kobold OPT Series 800-998-1020 www.kobold.com

Pulnix America Inc FL, FLH

OPL Series 888-525-7300 www.levelandflow. com

The conductivity float switch operates by utilizing electrodes to detect the presence or absence of liquid through conductivity measurement It functions by completing an electrical circuit between electrodes or between an electrode and a metal tank, relying on the conductive properties of liquids.

The cost of a conductivity float switch is approximately $40 to $800 depending on product or application requirements.

Tilt Switches

Tilt switches detect variations in position or rotation, triggering a switch in response to these changes These devices can be utilized for various applications, including activating alarms, controlling equipment, and turning on lights, among other functions.

A tilt switch is a multifunctional device essential for various position monitoring and control applications, such as video cameras and motion detectors It can either be integrated into existing products or acquired as a standalone component for specific customer needs, including use in mining operations Numerous products already utilize non-mercury tilt switches, showcasing their widespread adoption across different industries.

• Test & Laboratory Equipment: precision measuring devices, plotters, power supplies, etc.

• Heavy equipment: construction vehicles, cranes, hoists, chutes, scissor lifts, static platforms, etc.

• Industrial: processing equipment, conveyor controls, extruders, speed controls, foot pedals, coal level monitoring, etc.

• Marine: rudder controls, deep sea manipulators, salt water platforms, ship & barge leveling etc

• Medical equipment: x-ray machines, MRI scanners, position controls, wheelchairs, etc.

• Robotics: analog inputs, remote operated vehicles, creature animation, etc.

• Agriculture: tractors, conveyor controls, food processing, bins, silos, grain level monitoring, etc.

In today's technologically advanced landscape, various devices play crucial roles in enhancing safety and efficiency across multiple sectors Key components include signaling alarms and lights for immediate alerts, programmable logic controllers for automation, and personnel digital assistants for streamlined communication Security measures are bolstered by computer security and anti-tamper devices, while utility metering and pump control systems ensure optimal resource management Additionally, digital and video cameras enhance surveillance capabilities, and portable space heaters provide comfort in diverse environments Specialized equipment such as gyroscopes, laser instruments, and geophysical monitoring tools support precision in applications ranging from oil rig leveling to continuous casting Furthermore, advancements in navigation technology, including digital compass correction and land navigation systems, contribute to improved safety in both automotive and military contexts, while auto security systems protect against theft.

RVs, exercise equipment, automobiles, and various other items like glove compartments, video cameras, and commercial popcorn poppers play essential roles in modern life Additionally, electric organs, space heaters, and oil well pump controls contribute to both comfort and functionality Machine tools and fishing lures enhance productivity and leisure activities, while greenhouses and motion detectors support efficient agriculture and security Pneumatic tube communication, man-lifts, and antenna positioning are crucial in industrial settings, alongside mining and aircraft transportation, showcasing the diverse applications of technology in everyday life.

There are numerous design parameters that affect the specification and selection of a tilt switch for a particular product or application.

Tilt switch designs differ significantly among manufacturers, affecting technology choice, manufacturer selection, product model, options, and overall cost Key design parameters play a crucial role in these decisions.

• Measurement requirements: tilt or rotation angle, number of axes, etc.

• Switch points: number of control points, number of alarm points, field adjustable points, etc.

• Output contact rating: inductive loading

(amps, voltage, power), resistive loading

• Life expectancy: switch, controlled equipment, etc.

• Operating parameters: differential between control/alarm points, angle of operation, etc.

• Environmental conditions: temperature, pressure, explosiveness, shock, vibration, corrosiveness, moving equipment, etc.

• Input power requirements: 115 Volts AC,

230 Volts AC, 24 Volts DC, 12 Volts DC, other

• Switch output: single pole single throw, double pole double throw, normally open, normally closed, relay, etc.

• Other parameters: display requirements, enclosure material, intrinsically safe, cleaning requirements, space available for operation, signal time delay, etc.

Mercury tilt switches are compact devices consisting of small tubes with electrical contacts at one end When tilted, mercury moves to the lower end, creating a conductive path that completes the circuit Conversely, tilting the switch back interrupts the circuit Manufacturers report that the mercury content in these tilt switches varies significantly, ranging from 400 mg to 71,000 mg per switch, as documented to IMERC.

The cost of a mercury tilt switch is approximately

$2 to $300 depending on product or application requirements.

The mercury tilt switch is known for its exceptional reliability and extended operational lifespan due to its minimal components and absence of arcing It has successfully undergone life cycle testing for over one million cycles This switch can manage high inductive loads, operates quietly, eliminates contact bounce, and can be hermetically sealed for enhanced protection against environmental factors.

The mercury tilt switch contains mercury, which is becoming less desirable for many applications including the food and beverage industry.

The following are manufacturers of mercury tilt switches

International Numerous models 973-777-8405 www.comus- intl.com

Series 800-328-6170 www.electro- sensors.com

Milltronics Mill- tronics Tilt Switches

A metallic ball serves as the key component for establishing electrical connections, as it rolls in response to the tilt switch housing's movement Additionally, the ball can be manipulated by actuator magnets, utilizing the principles of spherical magnetism to enhance functionality.

The cost of a metallic ball tilt switch is approximately $1 to $11 depending on product or application requirements.

The metallic ball tilt switch is ideal for high EMI environments, such as generators and motors, as well as demanding applications that necessitate a durable switch When utilized with small rated loads, this switch can offer a long lifespan, making it a reliable choice for various industrial uses.

The metallic ball tilt switch is not ideal for environments with shock or vibration, as it may produce false contacts from bouncing Additionally, overheating or arcing can cause the metallic ball to weld to the electrical contacts Furthermore, this type of switch is limited to handling loads of two amps or less to avoid arcing problems.

The following are manufacturers of metallic ball tilt switches:

The electrolytic tilt sensor features multiple electrodes immersed in an electrically conductive fluid, maintaining a level surface due to gravity as it tilts The conductivity between the electrodes varies based on the length of immersion, analogous to a potentiometer where resistance changes with tilt angle The electrolyte's conductivity and viscosity can be adjusted to fit specific design requirements, and the voltage output from the sensor is suitable for various tilt switch applications.

The cost of an electrolytic tilt sensor is approximately $5 to $50 depending on product or application requirements.

Electrolytic tilt sensors are known for their exceptional repeatability, stability, and accuracy, making them ideal for various applications Designed to withstand extreme temperatures, humidity, and shock, these rugged sensors ensure reliable performance in challenging environments Additionally, their low power consumption enhances their efficiency and usability.

Electrolytic tilt sensors are complex devices due to their sensitivity to internal circuitry and external environmental influences.

The following are manufacturers of electrolytic tilt sensors:

Company Numerous models 215-947-2500 www.fredericksco m.com

Nanotron, Inc Ultimate I and II Series

The SP5000 and AU6000 series

Potentiometers consist of a curved conductive track with a connection terminal at each end and a moveable wiper connected to a third terminal.

Rotating the shaft of a potentiometer alters the length of the electrical path and the resistance in a proportional manner These devices are versatile and can effectively detect both linear motion and various degrees of rotation, including single and multiple turns.

Potentiometers were found to range from approximately $0.25 for simple, high volume applications to $300 for high quality audio applications

Potentiometers are inexpensive, reliable, and have long operational life, often greater than 20 million cycles Potentiometers are also available in micro-miniature size for space saving design requirements

The following are manufacturers of potentiometers:

760-929-0749 www.etisystems.co m/ singledesign.htm Precision

Series 416-744-8840 www.precisionelectr onics.com

A mechanical tilt switch, which can be a snap switch or micro-switch, operates through various actuation methods The most prevalent method involves a lever arm activated by a metallic rolling ball, whose position shifts according to gravitational changes and the movement of the switch housing.

The cost of a mechanical tilt switch is approximately $100 to $350 depending on product or application requirements.

The mechanical tilt switch is known for its high reliability and long operational life, capable of managing high inductive loads Additionally, it can be hermetically sealed to enhance protection against environmental factors such as dust and moisture These switches are engineered to endure over one million operational cycles, making them a durable choice for various applications.

Pressure Switches

A pressure switch is a device that transforms changes in pressure, vacuum, or differential pressure into an electrical switching function It utilizes a diaphragm, piston, or other pressure-sensitive sensors to activate mechanical switches, mercury switches, or transistors Common types of pressure-responsive sensors found in pressure switches include various mechanisms designed to ensure accurate pressure measurement and control.

A diaphragm actuated pressure switch features a large surface area and flexible diaphragm material, enabling it to convert small pressure or vacuum changes into mechanical force that activates a snap-action switch In a pressure switch, positive pressure exerts force on the diaphragm, while in a vacuum switch, negative pressure pulls it Differential switches connect both sides of the housing to two pressure sources, allowing the diaphragm to respond to the net force created by these pressures.

A piston actuated pressure switch employs a metal piston as its sensing element, making it highly durable and capable of functioning under high pressure and challenging environments Its robust design and use of stronger materials enhance its reliability in demanding applications.

A bellows actuated pressure switch operates using a flexible bellows element that expands and contracts in response to pressure changes The bellows interacts with an adjustable spring, which sets the pressure threshold needed to activate the switch This mechanism automatically opens or closes the electrical circuit based on whether the operating pressure exceeds or drops below a predetermined level.

A flex circuit diaphragm is a compact metal component etched from a single layer of a circuit board, designed to make contact with an additional layer, effectively integrating sensor and switch functionalities This innovative device offers the significant advantage of operating at high frequencies while maintaining a prolonged duty cycle.

Different types of sensors offer varying performance trade-offs that need to be carefully assessed for specific applications For instance, bellows actuated pressure switches demonstrate high sensitivity, but they may experience metal fatigue when used in applications with rapid cycling.

A pressure switch is a versatile component essential for various pressure monitoring and control applications, such as boilers, air conditioners, and vacuum cleaners It can be integrated into products or purchased separately for specific customer applications, including semiconductor processing Numerous products and applications utilize pressure switches, many of which may already employ non-mercury pressure switch technology.

• Heating, ventilation, and air conditioning: electrostatic air cleaners, filter indicators, reservoir level, gas fired heating, ventilation, utility heaters, heat pumps, furnaces, flue gas, fuel delivery, etc.

Medical technology encompasses a range of essential devices, including respiratory sensors, therapy tent nebulizers, and automated blood pressure systems These innovations also feature sip and puff movement controls, anesthesia leak detection, and saline pumps, which enhance patient care Additionally, tourniquet systems, reverse osmosis purification systems, and dental aspirator pumps play critical roles in medical procedures The field of respiratory therapy is supported by disposable surgical vacuum systems, ensuring effective treatment and improved outcomes for patients.

• Automotive: tire pressure, emission control, manifolds, air conditioning, engine crankcase pressure, air brakes, lumbar seat pressure, exhaust gas re- circulation, etc.

• Appliance: commercial dish washers, floor scrubbers, vacuum cleaners, food storage sealers, air conditioners, commercial fryers, hot water dispensers, hot water heaters, etc.

Fire pump controllers, scrubbers, venting hoods, and construction equipment are essential for various industrial applications Key components such as tape braking systems, tape tension controls, and door safety mechanisms ensure operational efficiency and safety In the realm of automation, spa pumps, machine tools, and automated test equipment play a crucial role in enhancing productivity Equipment like packaging machinery, pulp digesters, and boilers are vital for manufacturing processes Additionally, well heads, polymerization reactor vessels, and mine gas samplers contribute to energy and resource management Garage doors, industrial gas pressure sensing, and vacuum radon detection are important for safety and environmental monitoring Advanced applications include missile guidance, spray painting, semiconductor processing, and injection water systems Submarine navigation control, robotics, and organ systems showcase innovation in technology Moreover, pump control, automobiles, pressurized air systems, and bioprocess applications highlight the integration of engineering in everyday life Lastly, sanitary systems, hydraulic systems, sprayers, pressurized tanks, altitude sensing, portable test equipment, fire protection systems, and waste treatment plants are crucial for maintaining public health and safety.

There are numerous design parameters that affect the specification and selection of a pressure switch for a particular product or application.

The design of pressure switches varies significantly among manufacturers, influencing technology choice, manufacturer selection, product model, and overall cost Key factors such as sensor selection play a crucial role in determining the range, sensitivity, accuracy, lifespan, and cost of a pressure switch Understanding these critical design parameters is essential for making informed decisions in product selection.

• Variable measured: pressure, vacuum, differential

• Operating parameters: set-point, dead- band, factory set, field adjustable

• Enclosure: general purpose, weather resistant, explosion proof, etc.

• Switch type: mercury, snap switch, micro- switch, transistor, etc.

• Switch: number of poles, number of throws, amperage, voltage, hermetically sealed, etc.

• Materials: enclosure, sensor, switch, etc

• Visual display: status, power on, etc.

• Sensor type: diaphragm, bellows, piston, bulb & capillary, etc.

• Pressure: range to be measured, maximum operating pressure, etc.

• Life expectancy: time in service, number of cycles

• Electrical connection: terminal block, conduit, etc.

• Environmental conditions: shock, vibration, explosion, corrosiveness, temperature, humidity, radio frequency interference, etc.

• Other: pressure surge protection, test button, reset button, etc.

The mercury pressure switch typically uses a piston, diaphragm, or bellows acting as the pressure sensor to actuate the mercury switch.

The mercury content reported by manufacturers to IMERC for pressure switches was in the range of greater than 1,000 mg

The price of mercury pressure switches typically ranges from $150 to $170, according to data from two specific product models However, costs may vary significantly based on different product specifications and application needs Notably, one manufacturer offers similar pricing for both mercury and mechanical pressure switches that serve comparable functions.

The mercury pressure switch is known for its high reliability and extended operational life due to its minimal components and absence of arcing, successfully enduring over one million life cycle tests It effectively manages high inductive loads while operating quietly, eliminating contact bounce, and can be hermetically sealed for enhanced protection against environmental factors However, the presence of mercury in these switches is increasingly viewed as undesirable, particularly in applications within the food and beverage industry.

The following is a manufacturer of mercury pressure switches

BB, DP, and DA Series

The mechanical pressure switch typically uses a piston, diaphragm, bellows, or combination piston/diaphragm as the pressure sensor The sensor can either 1) directly actuate the switch, or

2) use a pushrod, lever, or compression spring to actuate a snap acting micro-switch.

The cost of a mechanical pressure switch is approximately $40 to $600 depending on product or application requirements.

Mechanical pressure switches are known for their high reliability and long operational lifespan, particularly when paired with diaphragm sensors that enhance accuracy Certain models incorporate a diaphragm and a negative rate Belleville spring, which offer exceptional resistance to shock and vibration, making them ideal for demanding environments.

The following are manufacturers of mechanical pressure switches:

PG, DP, APS, AVS, and DS-

Series 3000 and 5000, Series III and V

SOR Inc Series 20 800-676-6794 www.sorinc.com

Corporation Series 3000 440-205-7600 www.tecmarkcorp. com

Instruments Numerous models 888-438-2214 www.ti.com

Instrument GR2/4 www.weedinstrume nt.com

Solid-state pressure switches contain one or more strain gauge pressure sensors, a transmitter, and one or more switches all in a compact package.

Pressure switches not only open or close circuits but also offer proportional analog or digital outputs Solid-state pressure switches commonly utilize diffused silicon piezoresistive sensors, which consist of homogeneous silicon measuring cells made from two vacuum-welded silicon plates The piezoresistive effect in these sensors results in a resistance change that correlates directly with the measured pressure Additionally, thin film strain gauges can serve as pressure sensors, with a microprocessor processing the strain gauge data to activate the switching element, usually a transistor.

Solid-state pressure switches cost approximately

The cost of solid-state pressure switches ranges from $200 to $350, influenced by specific product or application requirements While this price is higher than that of mechanical or mercury pressure switches, solid-state options become more economical when monitoring multiple points and utilizing their additional features.

Temperature Switches

A temperature switch is a device that transforms temperature changes into electrical switching actions, utilizing a temperature-responsive sensor connected to various types of switches, including mercury switches, solid-state switches, micro-switches, and snap switches Commonly used temperature sensors in these switches play a crucial role in their functionality.

A thermocouple consists of two wires made from different metals, joined at one end, with the voltage measured at the opposite end When the temperature at the junction changes, it creates a corresponding change in electromotive force at the other end As the temperature increases, the output electromotive force of the thermocouple also increases.

There are many different types of thermocouples made of different types of wire with very different properties.

Resistance Temperature Detectors (RTD): An

RTDs, or Resistance Temperature Detectors, operate on the principle that a metal's electrical resistance varies with temperature changes This resistance typically increases in a nearly linear fashion as temperature rises RTDs are constructed using a length of conductor, such as platinum, nickel, iron, or copper, which is wound around an insulating material.

Modern resistance temperature detectors (RTDs) utilize a thin film conductor applied to a ceramic substrate, offering stability and a broad temperature range However, they are less durable and more costly compared to thermocouples, and they necessitate an electric current for accurate measurements.

RTDs are subject to inaccuracies from self- heating.

Thermistor: A thermistor is also based on the fact that the electrical resistance of a material changes as its temperature changes.

Thermistors rely on the resistance change in a ceramic semiconductor, with the resistance dropping non-linearly with a temperature rise.

Thermistors tend to be more accurate than

RTDs and thermocouples, but they have a much more limited temperature range because of their marked non-linearity.

Thermistors can be a low cost solution to temperature measurement They tend to have large signal outputs and their small size permits fast response to temperature changes.

Integrated Circuit Sensor: The newest type of temperature sensor on the market is the integrated circuit temperature transducer.

Integrated circuit sensors are highly linear devices capable of generating either voltage or current output, making them an efficient solution for producing an analog voltage that corresponds to temperature changes These sensors are specifically designed to measure temperatures within a limited range, operating effectively between -50° and 300° F.

A temperature switch is a versatile component essential for various temperature monitoring and control applications, such as food warming trays and hot water boilers It can be integrated into products or purchased as a standalone component for specific uses, like in plastics injection molding processes Many existing products already utilize non-mercury temperature switches, showcasing their widespread adoption across different industries.

Ovens, sterilizers, moulding machines, and heat exchangers are essential equipment in various industries, alongside labelling machines, water baths, and heat sealers Refrigerating and ventilating equipment, alarm systems, and mechanical components like bearings and gear reducers play crucial roles in operational efficiency Additionally, machinery such as bucket elevators, hammer mills, and generators, along with conveyors, dryers, and grinders, enhance production capabilities Essential appliances include motors, presses, mixers, and vending machines, while specialized equipment like dental tools, hot stamping devices, and food warming trays cater to specific needs Other important tools encompass hydraulic laminating presses, hot water boilers, and label adhesive applicators, which contribute to diverse applications ranging from textiles to livestock management.

When selecting a temperature switch for a specific application, it's essential to consider various design parameters that significantly influence the choice of technology, manufacturer, product model, and associated costs Key factors include the selection of sensors, which determine the switch's range, sensitivity, accuracy, lifespan, and overall cost Each manufacturer offers distinct design options, making it crucial to evaluate these critical design parameters for optimal product performance.

• Operating parameters: Set-point, dead- band, factory set, field adjustable

• Enclosure: general purpose, weather resistant, explosion proof, etc.

• Switch type: mercury, snap switch, micro- switch, transistor, etc.

• Switch: number of poles, number of throws, amperage, voltage, hermetically sealed, etc.

• Materials: enclosure, sensor, switch, etc

• Visual display: status, power on, etc.

• Sensor type: RTD, integrated circuit, thermistor, thermocouple, etc.

• Temperature: range to be measured, maximum operating temperature, storage temperature, etc.

• Life expectancy: time in service, number of cycles

• Electrical connection: terminal block, conduit, etc.

• Power input: 120/240VAC, 12/24VDC, current, etc.

• Environmental conditions: shock, vibration, explosion, corrosiveness, temperature, humidity, RFI, etc.

• Other: temperature surge protection, test button, reset button, etc.

A temperature switch utilizes a temperature-responsive sensor, such as a thermocouple, resistance temperature detector (RTD), or gas-actuated bourdon tube, to activate a mercury switch through mechanical means Manufacturers have reported that the mercury content in these temperature switches exceeds 1,000 mg, according to data submitted to IMERC.

The price of a mercury temperature switch ranges from $150 to $250, influenced by specific product or application needs Interestingly, one manufacturer offers a snap action temperature switch at a lower cost compared to a mercury temperature switch that provides equivalent functionality.

The mercury temperature switch is known for its exceptional reliability and extended operational lifespan due to its minimal components and absence of arcing Successfully tested for over one million cycles, it effectively manages high inductive loads while ensuring quiet operation and eliminating contact bounce Additionally, its hermetically sealed design offers enhanced protection against various environmental factors.

The mercury temperature switch contains mercury, which is becoming less desirable for many applications including the food and beverage industry.

The following table lists a manufacturer of mercury temperature switches

A mechanical temperature switch utilizes a temperature-responsive sensor that activates a mechanical switch through mechanical means Common types of these sensors include thermocouples, bulb and capillary systems, resistance temperature detectors (RTDs), welded alloys, and gas-actuated bourdon tubes.

The price of a mechanical temperature switch ranges from $8 to $600, influenced by specific product and application needs Notably, one manufacturer offers a snap action temperature switch at a lower cost compared to a mercury temperature switch that provides similar functionality.

Mechanical temperature switches are known for their high reliability and extended operational lifespan, making them capable of managing high inductive loads The effectiveness and precision of these switches significantly rely on the quality of the sensor technology implemented.

The mechanical temperature switch provides similar functionality to the mercury temperature switch without the attendant mercury management issues.

The following are manufacturers of mechanical temperature switches:

RRT, D-7435, DA-36, and DA-37 Series

Neo-dyn/ITT Industries Series 100T and 132T 661-295-4000 www.neodyn,co m

Series 800-257-3526 www.selcoprodu cts.com

Series 800-880-9333 www.weedinstru ment.com

Alternative 2: Solid State Temperature Switches

The solid-state temperature switch utilizes temperature coefficient thermistors, RTDs, or integrated circuits sensor to monitor temperature, and a semiconductor for the switching output.

A solid-state temperature switch typically ranges in price from $350 to $600, influenced by specific product or application needs This cost is generally higher compared to traditional mercury or mechanical temperature switches.

Relays

A relay is an electrically controlled device that manages the opening and closing of electrical contacts to operate other devices within the same or different circuits These devices are essential for switching large current loads while only requiring small currents for control Relays are categorized into two main types: electro-mechanical and semiconductor Electro-mechanical relays encompass various types such as mercury displacement, mercury wetted reed, mercury contact, and dry reed relays, along with other miscellaneous types On the other hand, semiconductor relays include solid-state relays and silicon controlled rectifiers.

Relays are versatile components essential for a wide range of products and applications, including copiers, heaters, and conveyors They can be integrated into existing products or purchased separately for specific customer applications, such as in petrochemical processing Many of these products already utilize non-mercury relays, showcasing their adaptability and importance in various industries.

• Commercial aircraft: power control, master power switches, motor control switching, heavy current load switching, instrument panel, generator switching, alternator power switching, antenna changeover, channel selection, etc.

• Air conditioning and heating equipment: compressor motors, fan motors, coolant pump motors, duct heaters, etc.

• Lighting controls: street lamps, dimmer controls, parking lots, scoreboards, high intensity lamps, traffic signals, tungsten lamps, etc.

• Telecommunications: trunk switching, test panels, telecomm circuit boards, load switches, radio base stations, ground start, input/output cards, control panel exchanges, antenna switches, loop current test, etc.

• Hospitals: surgical equipment, X-ray machine control, energy management systems, surgical lighting, etc.

• Food Industry: food processing, deep fryers, pizza ovens, baking ovens, electric grills, dishwashers, etc.

• Office equipment: copiers, computer power supplies, blue print machines, etc.

• Manufacturing: injection molding machines, kilns, ink heating, vacuum forming, soldering systems, semiconductor processing, programmable logic controllers, etc.

• Production test equipment: component testers, cable testers, circuit testing, etc.

• Laboratory test instruments: voltmeters, ohmmeters, recorders, environmental chambers, etc.

• Machine tool control: solenoid operated valves, heavy motor starting, signal lights, etc.

The article highlights a diverse range of equipment and technologies essential for various industries, including mining, aerospace, and petrochemical processing Key items mentioned are mining equipment, pool heaters, industrial furnaces, and notebook computers, alongside specialized tools like engraving equipment, plastic extruders, and steam generators Additionally, it covers essential machinery for packaging, pharmaceuticals, textiles, and automotive sectors, such as printing machines, robotics, and infrared dryers The list also includes advanced systems like alarm systems, battery chargers, and communication modules, emphasizing the importance of high-temperature materials processing and energy-efficient appliances in modern manufacturing and technology.

In 2001, the global relay market generated revenues of $4.658 billion, with electromechanical relays accounting for 89.1% and semiconductor relays making up 10.9% The leading applications for relays included telecommunications (25.3%), transportation (18.4%), and industrial automation (12.4%) When selecting a relay for specific applications, various design parameters play a crucial role in determining the appropriate specifications.

• Mounting: printed circuit board, din rail, bracket/flange mount, socket/plug-in style, surface mount, etc.

• Reliability: failure rate, mean cycles before failure (MCBF), etc.

• Enclosure: open, National Electrical Manufacturers Association (NEMA), hermetically sealed, etc

• Pole specifications: single pole, double pole, triple pole, etc.

• Throw specifications: single throw, double throw, etc.

• Contact ratings: maximum switching current (amps), maximum switching voltage, maximum switching power

• Contacts: normally open, normally closed, contact material, etc.

• Materials: contacts, insulation, soldering fluxes, finishes, etc.

• Voltage: Direct current or alternating current

• Load types: inductive, motor, lamp, etc.

• Load characteristics: inrush current, step up, ramp up, soft start, etc.

• Life expectancy: electrical components, mechanical components, controlled equipment, etc.

• Physical: weight, size, noise level, etc.

• Coil ratings: voltage range, resistance range, nominal power, etc.

• Performance specifications: make/operate time, break/release time, contact chatter, contact bounce, time delay, etc.

• Environment: operating temperature, shock, vibration, acceleration, humidity, etc.

• Control panel: space available, natural convection available, etc.

• Output device for solid-state relays: metal oxide semiconductor field effect transistor (MOSFET), silicon controlled rectifier, bipolar transistor, triac, etc.

• Other features: time delay, instrinsically safe, visual indicators, sealed enclosure, test button, latching controls, energy efficiency, etc.

Venture Development Corporation conducted interviews with original equipment manufacturers regarding their selection criteria for relays used in their products The findings revealed key factors influencing their choices, which are summarized in the accompanying table.

Table 4.6: Most Important Relay Product Selection Criteria

Product Selection Criteria Percent of OEM

Respondents Citing as Most Important

A Mercury Displacement Relay

The mercury displacement relay operates using a lightweight metallic plunger that floats on mercury and features a magnetic sleeve, allowing it to be drawn down into the mercury by a magnetic field This plunger functions similarly to an armature in a mechanical relay When the coil power is off, the mercury level remains below the electrode tip, preventing any current flow between the insulated center electrode and the mercury Once power is applied to the coil, the plunger is pulled down into the mercury, establishing a current path When the coil power is removed, the buoyancy of the mercury lifts the plunger back to its original position, decreasing the mercury level and interrupting the current flow.

Mercury displacement relays contain varying amounts of mercury, influenced by factors such as the number of poles, current rating, and termination requirements Manufacturers have reported mercury levels exceeding 1,000 mg to IMERC for these relays.

Mercury can be released into the environment during the use of products, particularly if a short circuit occurs, which may cause the mercury relay (MDR) to burst To mitigate this risk, some manufacturers provide free take-back programs for their mercury relays.

Mercury displacement relays are essential components in high current and high voltage applications, including industrial process controllers, power supply switching, resistance heating, tungsten lighting, welding, and high-intensity lighting systems They are also utilized in flood lights, copiers, battery chargers, energy management systems, and industrial ovens, showcasing their versatility in various industrial settings.

The price of a mercury displacement relay ranges from $20 to $150, influenced by specific product or application needs This cost is similar to that of other electromechanical relays While mercury displacement relays are generally more affordable than solid-state relays for low current applications, their prices become comparable in higher current scenarios.

Mercury displacement relays have hermetically sealed contacts that provide internal and external protection from arcing and environmental abuse.

Mercury displacement relays offer several advantages over mechanical relays, including faster cycling speeds and low contact resistance due to their large contact mating areas created by the surrounding mercury These relays ensure quiet operation by eliminating acoustical noise from rebounding contacts and boast a long lifespan, averaging between 1,000,000 to 10,000,000 cycles, thanks to their single moving part and absence of pivots or mechanical linkages, which minimizes wear Longevity is influenced by factors such as the voltage being switched, the ratio of line voltage to rated voltage, and the number of cycles per hour Additionally, mercury displacement relays provide bounce-free operation, as the mercury's surface tension allows it to bridge contacts during plunger settling time.

Mercury displacement relays must be installed in a specific orientation to ensure proper functionality, as improper mounting can lead to overheating and potential bursting, creating hazardous waste issues Additionally, the disposal of worn-out contactors can be costly, and these relays offer limited control compared to solid-state alternatives Furthermore, thermal shock may affect the equipment managed by the relay, highlighting the need for careful consideration in their use.

The following are manufacturers of mercury displacement relays:

Chromalox HGR series 800-443-2640 www.chromolox.com

Numerous models 616-663-8574 www.mdius.comWatlow Electronic HG Series 507-454-5300

B Mercury Wetted Reed Relay

A mercury wetted reed relay is an electro-mechanical device featuring a hermetically sealed reed switch, composed of thin flat ferromagnetic blades that function as a contact, spring, and magnetic armature This relay design includes a glass-encapsulated reed, with one end submerged in mercury, allowing it to move between two sets of contacts The mercury ascends the reed through capillary action, effectively wetting both the reed's contact surface and the stationary contacts Typically, the relay is activated by a coil surrounding the capsule.

Wetted mercury reed relays are compact circuit controls utilized in electronic devices for switching and signal routing They are essential in test, calibration, and measurement equipment, providing reliable performance with stable contact resistance throughout their lifespan.

Prices for the mercury wetted reed relay ranged from approximately $10 for printed circuit board mounted low amperage devices, to $40 for larger

When comparing the costs of 5 amp devices, mercury wetted relays are similarly priced to dry magnetic reed relays for one manufacturer, while another manufacturer lists mercury wetted relays at double the price of their dry counterparts Overall, the pricing for mercury wetted relays tends to be comparable to that of dry reed relays across different manufacturers.

However, life cycle costs are higher for the mercury wetted reed relay due to the higher costs associated with shipping, management, and disposal of the mercury containing device.

Hermetically sealed contacts in a clean atmosphere protect against dust, corrosion, and oxidation, preventing issues like sticking or binding in hinged joints Magnetic reed relays, with proper circuitry, can exceed one billion operations and operate in the millisecond range, making them suitable for high-speed switching applications While slower than solid-state relays, reed relays are faster than other electro-mechanical options and require simpler, more cost-effective coupling circuitry between logic and input/output devices Additionally, mercury wetted reed relays offer advantages over dry reed relays, including no contact bounce, extended lifespan, and reduced contact resistance.

Reed relays designed for inductive loads, including motors and solenoids, can experience high induced voltages when the load circuit contacts open, potentially damaging the reed switch or shortening its lifespan Similarly, reed relays handling capacitive loads, such as capacitors and incandescent lamps, face issues with high surge or inrush currents, necessitating the use of protective circuits like surge suppressors or current limiting resistors Additionally, reed relays situated near strong magnetic interference sources, such as steel plates and transformers, may exhibit altered operational characteristics and are prone to false triggering For optimal performance, wetted mercury reed relays should always be installed in a vertical position.

Dry reed magnetic relays can effectively substitute mercury wetted reed relays in most applications, except for those that demand zero contact bounce, extended operational life, or minimal contact resistance.

The following are manufacturers of mercury wetted reed relays:

Numerous DIP, SIP, and encapsulated , models

C Mercury Contact Relay

The mercury contact relay operates by creating contact between electrodes within a sealed capsule, triggered by the tilting of the capsule through an electro-magnetically actuated armature during either the pickup or dropout process Currently, there are no manufacturers producing this type of mercury relay, and as a result, this report will not provide additional information on this relay type.

A dry magnetic reed relay features two slender, flattened ferromagnetic reeds that are hermetically sealed in a glass tube, positioned in a cantilever manner with a small air gap When exposed to a magnetic field, the ends of the reeds develop opposite magnetic polarities, causing them to flex towards each other and make contact when the magnetic flux density is sufficient This contact mechanism can operate at extremely high speeds and is capable of millions of cycles Additionally, energizing the coil generates a magnetic field similar to that of a permanent magnet, while the contact area is typically coated with rhodium, ruthenium, or gold to ensure low contact resistance.

Dry magnetic reed relays are compact circuit controls commonly found in electronic devices, particularly in test, calibration, and measurement equipment They are essential for applications requiring stable contact resistance throughout the product's lifespan.

Dry magnetic reed relays typically range in price from $2 to $15, influenced by specific product and application needs One manufacturer offers mercury wetted relays at a price comparable to that of dry magnetic reed relays for similar devices, while another manufacturer prices mercury wetted relays at twice the cost of their dry magnetic counterparts.

The dry magnetic reed relay has long operational life, fast cycling time, no mercury life cycle impacts to address, and can be mounted in any position for proper operation.

The dry magnetic reed relay is susceptible to electromagnetic interference, much like the mercury wetted reed relay High voltage exposure can lead to the welding of contacts Compared to mercury wetted relays, dry magnetic reed relays exhibit increased contact bounce, a shorter operational lifespan, and higher contact resistance.

The following are manufacturers of dry magnetic reed relays:

Relays, Inc Numerous models 562-944-0447 www.americanrelays. com

Numerous models 800-864-2815 www.relays- unlimited.com

Technology Numerous models 401-943-2686 www.cotorelay.com

H, LI, HE, MRX, MT and other series

Electro-mechanical relays can be classified into various types, including mercury displacement, mercury wetted reed, and dry reed relays This article will specifically explore other categories of electro-mechanical relays, such as general purpose relays, definite purpose relays, heavy duty relays, and printed circuit board mounted relays.

Electromechanical relays operate by utilizing electromagnetic principles, where an electric current flows through a coil to create a magnetic flux This magnetic flux activates an armature, leading to the opening or closing of isolated electrical contacts.

Electro-mechanical relays typically range in price from $1 to $35, influenced by specific product and application needs However, as the power level requirements increase, the cost of these relays tends to rise, making them less competitive compared to solid-state relays.

Electromechanical relays are frequently chosen as safety devices due to their complete mechanical break in the electrical circuit, unlike solid-state units that may experience leakage current Additionally, their low initial cost makes them an attractive option These relays are particularly advantageous in environments where electrical interference is a concern or when low heat dissipation is essential.

Electro-mechanical relays often have a limited operational lifespan, typically wearing out mechanically or electrically after several hundred thousand cycles, which is significantly shorter than that of mercury or solid-state relays This limited lifespan can lead to considerable labor costs and production downtime when failures occur, especially in high cycling applications Additionally, these relays exhibit slower cycle times, resulting in inadequate control of equipment for sensitive applications, potentially causing damage to the controlled equipment and reducing the lifespan of heaters due to thermal shock.

The following are manufacturers of other electromechanical relays:

TC Series 800-870-5385 www.meder.com

SRC Devices LM Series 858-292-8770 www.srcdevices.com

A solid-state relay is a semiconductor, electronic switching device that operates a load circuit without the use of physical mechanical contacts.

A solid-state relay features an input circuit, an opto-coupler chip, and an output circuit that effectively switches both alternating current (AC) and direct current (DC) voltage These relays manage power control by toggling on and off at the zero cross point, ensuring efficient operation.

The cost of a solid-state relay is approximately

$1 to $150 depending on product or application requirements.

Solid state relays offer numerous benefits, including an extended operational lifespan, immunity to electromagnetic interference, and reduced power consumption They operate at high speeds with bounce-free performance and require low-level control signals, all while being compact in size and allowing for multifunction integration When mounted on printed circuit boards, solid-state relays significantly save space compared to traditional electromagnetic relays Additionally, they are more resilient to physical shock, vibration, and damage Testing by one manufacturer indicated a remarkable mean time between failure (MTBF) of thirty-three years for solid-state relays, and unlike dry reed relays, they eliminate contact bounce and provide a longer operational life.

Solid-state relays generate heat due to voltage drops when current flows through them, necessitating effective heat dissipation methods such as heat sinks or cooling fans To ensure safety, proper fusing is essential for short circuit protection, and transient voltage spikes are typically mitigated using metal oxide varistors These relays function by either fully turning circuits on or off, providing controlled equipment with either complete or no current Some manufacturers utilize infrared light emitting diodes (LEDs) made from gallium/aluminum/arsenic for optically coupled input control However, solid-state relays may experience current leakages, and their contact resistance is generally higher compared to mercury wetted relays.

The following are manufacturers of solid-state relays:

Carlo Gavazzi (Switzerland) U.S Rep - Allied

RN and RS1A Series Allied:

Celduc Relais (France) Laube Technology –

805-388-1050 www.celduc- relais.com Chromalox 7750 Series 800-443-2640 www.chromolox.co

PV Series 310-322-3331 www.irf.com

RS1 and RS3 Series 973-748-5089 www.nteinc.com

Optronics, Inc Numerous models 888-377-4776 www.ssousa.com

SSRD, SSRQ, and SSRT Series

800-468-2023 www.relay.tycoelec tronics.com

Vishay LH Series 402-563-6866 www.vishay.com

SSR Series 507-454-5300 www.watlow.com

The silicon controlled rectifier (SCR) acts as a fast-switching device that efficiently regulates power in various applications Composed of four layers of semiconductor material, SCRs are capable of delivering electrical power to controlled equipment through multiple methods.

• Phase-angle-fired controls – Provides smooth, variable application of power to heaters.

• Zero-voltage switching controls – Proportionally turns on and off each full cycle of the power line.

• On/off controls – Function similar to electro-mechanical or mercury relays, but has much faster cycle times.

The price of silicon controlled rectifiers ranges from $30 to $150, influenced by specific product and application needs While their cost is generally higher than that of electromechanical relays at low power levels, it becomes more competitive with electromechanical relays as power levels increase to mid and high ranges.

Flame Sensor

Flame sensors serve as essential safety devices in gas appliances by detecting the presence of an open flame If the pilot light goes out or if there is a malfunction, the flame sensor will automatically halt the flow of gas to prevent potential hazards The sensor contains mercury, which vaporizes and expands when the pilot light is functioning, allowing the gas valve to open safely.

Flame sensors vary in cost, making it challenging to pinpoint exact price differences A comparison between gas ranges equipped with mercury flame sensors and those featuring electronic ignition systems revealed similar price ranges, typically between $300 and $1000.

A low-end quality name gas range with an electronic ignition and a gas range with a mercury flame sensor were both around $300.

The top manufacturer of mobile home products provides an advanced electronic ignition system in its product lineup, including hot water heaters Product literature indicates no price variation for these options, with nearly all models available featuring either electronic ignition flame detection or a mercury flame sensor.

The mercury flame sensor provides the safety of controlling the flow of gas when no flame is lit.

To ensure safety and prevent serious situations caused by natural gas leaks, most manufacturers provide electronic ignition flame detection units that utilize mercury-free sensors.

The following are manufacturers of mercury flame sensors:

Mercury Flame Sensor 1-800-387-817 www.andybaume nltd.com

Flame Sensor 314-577-1300 www.white- rodgers.com

Flame Sensor 508-881-2000 www.fenwalcont rols.com

Flame Sensor 44-1208-72565 www.derlite.com

630-870-3300 www.harper- wyman.com Invensys

847-593-0796 www.majorintern ational.com Sit La Precisa

An electronic ignition system in gas appliances replaces the traditional standing pilot light, enhancing safety and efficiency This system ignites gas instantly when activated, preventing gas buildup and ensuring immediate lighting.

In general, the difference in cost between a range with an electronic ignition and the cost of a range with a mercury flame sensor is negligible.

However, one manufacturer indicated that the price of their electronic ignition range was 10% -

The starting price for a low-end gas range with electronic ignition is $300, while models featuring a mercury flame sensor are priced approximately 20% higher, ranging from $300 to $1000.

A majority of the manufacturers identified offered an electronic ignition flame detection unit that does not use mercury in its sensor

The top manufacturer of mobile home products provides an electronic ignition system across its range of hot water heaters Product literature indicates no cost difference between models, with nearly all units available featuring either electronic ignition flame detection or a mercury flame sensor.

When using electronic ignition gas products, a primary concern is the necessity of electricity for operation, which poses safety risks in remote areas without power Although electronic ignition flame detection products can be ignited without electricity, they lack safety features to manage gas flow In contrast, mercury flame sensors operate independently of electricity, providing both flame detection and gas flow control While electronic ignition systems do not include mercury-based devices, they serve as a viable alternative for safe gas appliance operation.

The following are manufacturers of electronic ignition systems:

Flame Sensor 908-272-9262 www.ventronicsi nc.com

Flame Sensor 903-984-3061 www.steelman.c om

Flame Sensor 630-870-3300 www.harper- wyman.com Invensys

Electronic Flame Sensor 804-756-6524 www.invensys.co m

Flame Sensor 414-524-1200 www.johnsoncon trols.com Major

847-593-0796 www.majorintern ational.com Sit La Precisa

The electric ignition system serves as a cost-effective and functional replacement for mercury flame sensors, widely utilized across various applications However, in remote areas with unreliable electricity, electronic ignition systems may not be a safe substitute Additionally, retrofitting existing products with electronic ignition systems can be challenging due to the highly integrated nature of mercury flame sensors within these devices.

CONCLUSIONS AND RECOMMENDATIONS

Conclusions

Research indicates that numerous mercury-containing products can be effectively substituted with non-mercury alternatives that offer equal or superior functionality, all while maintaining comparable costs.

This study identified at least one manufacturer offering non-mercury alternatives for most priority products, revealing minimal cost differences between mercury and non-mercury technologies The findings indicate that a variety of non-mercury options are available to fulfill the diverse functions needed in consumer products.

The report highlights various product-specific mercury replacement programs, alongside initiatives that target multiple mercury-containing products One notable example is the Mercury Pollution Prevention program, which aims to reduce mercury usage across different product categories.

Three Indiana steel mills are actively working to inventory products containing mercury, identify non-mercury alternatives, and replace these mercury products This initiative targets various items, including barometers, manometers, hydrometers, pyrometers, thermometers, thermostats, pressure switches, tilt switches, float switches, and relays.

An inventory assessment revealed that around one thousand pounds of mercury were found in equipment and devices across three steel mills These mills have pledged to reduce mercury levels by 330 pounds by the end of 2000, 660 pounds by 2004, and 900 pounds by 2008.

Legislation to address mercury containing products has been in existence since the early

In 1993, Sweden implemented a ban on the manufacture, import, and sale of various mercury-containing measuring instruments, including thermometers, barometers, and pressure switches, with some exemptions for spare parts This action aligns with similar restrictions imposed by other European countries on the use and sale of mercury-containing products.

In the United States, state-level legislation is being implemented to regulate the sale of mercury-containing products Recently, Rhode Island and Connecticut have enacted laws to phase out these products, following the guidelines of the NEWMOA Mercury Model Legislation.

Several manufacturers offer alternatives to mercury sphygmomanometers, including aneroid (dial) sphygmomanometers, which have similar functionality and pricing Additionally, a newer category of electronic blood pressure monitors is emerging, starting at around $700—about five times the price of the most affordable mercury gauges These electronic devices are marketed as easier to use and capable of delivering more detailed blood pressure information.

Tungsten gel-filled bougies are readily available from medical device manufacturers and appear to be quite acceptable to practitioners

Research indicates that gastrointestinal tubes are infrequently utilized, and these tubes are typically sold without mercury Consequently, facilities opting to use these tubes must provide their own mercury for weighting purposes One manufacturer recommends the use of sterile water for weighting, although this may prolong the duration of the medical procedure.

Digital and vacuum gauge manometers are viable and cost-effective alternatives to traditional mercury manometers The digital manometer offers high accuracy, and regular calibration is essential to maintain its precision.

Non-mercury basal thermometers, including digital and liquid-in-glass options, are widely available and appealing to consumers Digital basal thermometers provide advantages over mercury versions, such as an easy-to-read display, a beep to indicate maximum temperature, and memory functionality Additionally, one supplier offers a liquid-in-glass thermometer that closely resembles and functions like a mercury basal thermometer While non-mercury options may be slightly more expensive—by just a few dollars—they are still comparable in price to some single-use fertility products and represent an infrequent purchase.

(e.g over-the-counter pregnancy test kits)

There are numerous effective alternatives to mercury thermometers that are readily accessible in the United States These non-mercury options have been utilized for various applications and are recognized for their accuracy, comparable to that of traditional mercury thermometers Additionally, the cost associated with transitioning from mercury to these safer alternatives is minimal.

Aneroid barometers can be manufactured with or without mercury Some digital barometers can perform other tasks, and therefore cost more.

Digital barometers can be an affordable option for measuring atmospheric pressure, often competing in cost with aneroid barometers Both digital and aneroid models present viable alternatives to traditional mercury barometers.

Hygrometers and psychrometers are essential tools for measuring relative humidity Both devices can effectively utilize a spirit-filled thermometer as an alternative to mercury thermometers, offering the same functionality at comparable costs.

The hydrometer serves various purposes, with its main application found in the beer and wine making industry For optimal reliability and cost-effectiveness, a spirit-filled hydrometer is often favored over traditional mercury hydrometers.

Recommendations

Research indicates that there are cost-effective, viable non-mercury alternatives for most priority mercury-containing products The purchase price of these alternatives is often comparable to that of mercury devices, and when considering downstream costs, non-mercury options can be significantly more economical For further assistance in transitioning to non-mercury alternatives, additional information is available in Appendix 3.

Research has identified non-mercury alternatives for various instruments, including sphygmomanometers, esophageal dilators, manometers, barometers, non-fever thermometers, hygrometers, psychrometers, hydrometers, flow meters, and pyrometers However, gastrointestinal tubes and industrial thermostats remain challenging, as comprehensive alternative replacements are not universally applicable Further investigation is essential to explore the use of non-mercury options for gastrointestinal tube applications and assess the feasibility of replacing mercury in these devices.

Digital thermostats often struggle to endure the extreme environmental conditions found in some industrial settings, making mercury thermostats the only reliable option currently available for effective performance in these applications.

Cost-effective non-mercury alternatives are available for various components such as flame sensors, float switches, tilt switches, temperature switches, and pressure switches, often meeting design parameters at a comparable cost While most new relay products can utilize these alternatives, some specific design requirements may not be fulfilled Additionally, electronic ignition systems are not advisable for replacing mercury flame sensors in remote areas lacking electricity Non-mercury options have been identified for retrofitting existing relay and switch products, although certain retrofit situations may render these alternatives economically unfeasible.

SOURCES

Barr Engineering Company, “Substance Flow

Analysis of Mercury in Products” Prepared for the Minnesota Pollution Control Agency, August

California DHS, A Guide to Mercury Assessment and Elimination in Health Care Facilities.

California Poison Control System, University of

California (2000-2002) “Mercury and its Many

Forms” Available at: http://www.calpoison.org/public/mercury.html

Canzanello, Vincent J., MD; P.L Jensen, RN; GL

Sphygmomanometers Accurate in Hospital and

Clinic Settings?”, Arch Intern Med

Clean Car Campaign, Driving Forward – Switch the Switch, Volume 3, March 2002.

Delta Institute, Inland Ispat Indiana Harbor

Works, Bethlehem Steel Burns Harbor Division,

United States Steel Gary Works, and Lake

Michigan Forum, “A Guide to Mercury

Reduction in Industrial and Commercial

Settings”, July, 2001 Available at: http://delta- institute.org/Steel-Hg-report-0627011.pdf

Corporation, An Executive White Paper On: The

World Electromechanical and Solid State Relay

Industry, Fifth Edition, Volume I – North

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Hoerr, Donald, Solid-State Pressure Switches – Technology for Today’s Fluid Power

ICL Calibration Laboratories, www.iclslabs.com.

Inform, Inc., Purchasing for Pollution Prevention Project (2002) “Mercury-Containing Products and Alternatives in the Health Care Setting” Available at: http://www.informinc.org/fsmerchealth.pdf (August, 2002).

Kansas Department of Health and Environment,

“Mercury Information Page” Available at: http://www.kdhe.state.ks.us/mercury/ (August, 2002).

Knoop, Alan R., Fundamentals of Relay Circuit Design, Reinhold Publishing, New York.

Maine Department of Environmental Protection,

“Mercury in Maine: A Status Report”, February 2002.

Minnesota Pollution ControlAgency, Managing Mercury Switches: Hazardous Waste Fact sheet

Minnesota Office of Environmental Assistance Mercury applications in major appliances and heating/cooling systems, April 1998.

Minnesota Office of Environmental Assistance, Mercury in Households and Commercial products and applications, John Gilkeson, November 1997.

Minnesota Pollution Control Agency, “Mercury”. Available at: http://hubble.pca.state.mn.us/air/mercury.html (August, 2002).

National Association of Relay Manufacturers, Engineers Relay Handbook 2 nd and 5 Edition, th Hayden Book Company, New York.

New York Academy of Sciences, “Pollution Prevention and Management Strategies for

Mercury in the New York/New Jersey Harbor”,

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Association, “Reported Mercury Spills in the

Offner, Arnold, How do Relays Work, Motion

Pollution Probe, A Study of the use of Mercury

Switches in Bilge Pumps of Pleasure Boats in

Powell, William B and Pheifer, David, “The

Electrolytic Tilt Sensor”, Sensors, May 2000.

Pulse Metric, Inc., “Non-Invasive Blood Pressure

Measurement and Pressure Waveform Analysis”,

Purdue University, Department of Agricultural and Biological Engineering “What Devices

Contain Mercury?” Available at: http://pasture.ecn.purdue.edu/~epados/mercbuild/ src/devicepage.htm (August, 2002).

Sedivy, David, Electronic Controls Spawn

State of California Department of Health

Services, “A Guide to Mercury Assessment and

Elimination in HealthCare Facilities”, September

2000 Available at: http://www.dhs.cahwnet.gov/ps/ddwem/environ mental/med_waste/guide_to_mercury_assessmen t_v1.00.pdf (August, 2002).

State of Maine Statutes, Title 38, Chapter 16-B,

Mercury-added Products and Services.

Environmental Improvements Through Better Environmental Accounting”, July 2000.

Timbrell, J.A., “Introduction to Toxicology”, Second Edition, 1995, Taylor & Francis; pp 118- 121.

United Nations Environment Programme (UNEP), (July, 2002) “Global Mercury Assessment” Available at: http://www.chem.unep.ch/mercury/WG- meeting1-revised-report-download.htm (October, 2002).

United States Environmental Protection Agency, Mercury Study Report to Congress, December 1997.

United States Environmental Protection Agency and Environment Canada, “Background

Information on Mercury Sources and Regulations; Appendix C Regulations on Products that Contain Mercury” Available at: http://www.epa.gov/grtlakes/bnsdocs/mercsrce/9 409merc.pdf (August, 2002).

United States Geological Survey, “Mercury in the Environment”, Fact Sheet 146-00 (October 2000)

United States Geological Survey, 2002 Mineral Commodity Summary – Mercury.

University of Michigan Pollution Prevention Program, “Mercury-Filled Esophageal Devices” Available at: http://www.p2000.umich.edu/mercury_reduction/ mr1.htm (August, 2002).

Von Rein, K and Hylander L.D., Experiences from Phasing out the Use of Mercury in Sweden, Regional Environmental Change, 2000, 1:126- 134.

Williams, Raymond R., Sensors Magazine, April

1997, “An Introduction to Solid State Pressure Switches”.

Winkler, Robert, and Wells Erik A., “The UVM Mercury Thermometer Swap January, 1999 Available at: http://esf.uvm.edu/chemsource/thermoswap/ (October, 2002)

Wisconsin Department of Natural Resources,

Draft Wisconsin Mercury Source Book.

Wisconsin Department of Natural Resources, Success Stories & Partnerships, August, 2002 Available at: http://www.dnr.state.wi.us/org/caer/cea/projects/p ollution/reports/1999/report2_p6.htm (October 2002)

Yeats, Mike, Derriford Hospital, Plymouth, UK,

“The Maintenance of an Aneroid

World Federation of Societies of

Anaesthesiologists Available at: http://www.nda.ox.ac.uk/wfsa/html/u03/u03_018.htm (August, 2002).

Medical Device Reports for Spilled Mercury

The United States Food and Drug Administration (FDA) oversees the regulation of medical devices, implementing the Medical Device Reporting (MDR) system in 1990 to efficiently receive and address significant adverse events related to these devices from manufacturers, importers, and user facilities This system has highlighted potential health and environmental issues associated with mercury in healthcare Each reported incident necessitates thorough investigation and documentation by the reporting facility, the manufacturer, and the FDA to ensure proper remediation and safety.

05/09/2002 Baumanometer Stand-by Blood Pressure Machine

“A blood pressure unit blew, causing 2.5 ounces of mercury to vaporize.”

“Glass tube containing mercury on Baumanometer cracked causing mercury to spill in facility.”

“It is reported that the tip of the bougie broke off during use

The distal end of the device was not recovered during the incident, and upon its removal, it was observed that mercury was leaking from the fractured end of the tube.

10/12/1999 Pilling-Weck Maloney Esophageal Dilator 24 Fr.

“During procedure, a bougie dilator for esophagus was transected inside the stomach, allowing mercury from the dilator to escape The bougie that was used for the procedure had been expired.”

“It is alleged that a Cantor tube was inserted and mercury instilled A subsequent x-ray indicated the presence of mercury in the stomach.”

Cost of Mercury Spills

Large spill - $tens of thousands http://www.melg.org/mcea/rcbmcrmt.htm

"Mercury Contamination Risk Control", Middle Cities Risk Management Trust, Okemos, MI

A standard thermometer typically contains 2 to 3 grams (0.018 to 0.11 ounces) of mercury, while a household mercury fever thermometer holds about 1 gram In contrast, a barometer contains 1 pound (454 grams) of mercury, which presents a significant risk for spills The cleanup costs for mercury spills vary based on the spill size and exposure level, with small spills averaging around $1,000 and larger incidents potentially costing tens of thousands of dollars.

Not uncommon … to exceed $25,000 http://cc.ysu.edu/eohs/bulletins/MERCURY.htm

"The Hazards of the Element Called Mercury," Youngstown State University

A small amount of mercury can lead to significant health and safety issues, as demonstrated by an incident involving three broken oral fever thermometers in a ten-square-foot office The resulting mercury vapors exceeded OSHA's permissible levels by three times, necessitating decontamination and the disposal of all carpeting at a cost of approximately $5,000 Such incidents highlight the potential for cleanup costs from mercury spills to surpass $25,000, even from seemingly minor spills.

Reported costs went up to $130,000 c) http://www.des.state.nh.us/nhppp/hospital_survey.htm

New Hampshire Mercury Reduction Project: Hospital Baseline Survey 1999 Preliminary survey results, New Hampshire Department of Environmental Services

In 1998, seven hospitals reported incidents of mercury spills or equipment breakages, although the true number of such incidents is likely higher due to unreported small spills Many hospitals were unaware of the cleanup costs, but reported expenses reached as high as $130,000.

In a significant case, a cleanup operation for a spilled sphygmomanometer cost $10,054, highlighting the financial implications of managing medical waste This incident was discussed during the Medical Industry Waste Prevention Round Table, focused on reducing mercury in hospitals and biomedical facilities, held on May 23, 2001, in King County, Seattle, WA.

Economic considerations highlight the significant costs associated with mercury sphygmomanometers, with cleanup expenses averaging around $5,000 for a single device, while non-mercury alternatives can be purchased for the same price For instance, a local hospital incurred a staggering $10,054 for the cleanup of a spilled sphygmomanometer Additionally, regulatory costs include potential fines for exceeding the 30-ppt pretreatment level, expenses related to hazardous waste training, and compliance with the Joint Commission on Accreditation of Health Care Organizations (JCAHO), which is increasingly scrutinizing these practices.

$570,000 to clean up after sink trap work

Environmental service (alone) for any spill costs

$1000-1500 http://dnr.metrokc.gov/swd/bizprog/waste_pre/MIRTsem8.htm

"Question: How did you get voluntary switch-out of Hg?

Virginia residents recall the significant mercury spills and are committed to preventing similar incidents in the future The University of Washington consistently relies on Foss Environmental for spill response services, which come at a cost of $1,000.

Someone at Bowling Green University changed their sink traps, piled them up and carried them across campus Mercury was spread everywhere Cost $570,000 to clean up."

$350,000 to clean up contamination and restore building to original condition http://204.178.120.25/library/college.htm

A recent plumbing project at a large Ohio university's science lab uncovered a significant mercury spill, leading to widespread contamination in the building The cleanup and restoration efforts to address the mercury contamination incurred costs of $350,000.

Transition to Non-mercury Products

Substituting mercury-containing products with safer alternatives presents numerous challenges, as most alternatives are not direct replacements While these alternatives can achieve similar results, such as accurately measuring blood pressure or detecting flames, they often require new design considerations and techniques that must be learned and effectively communicated Additionally, even in optimal conditions, the transition carries risks and may lead to unforeseen outcomes, both positive and negative.

A manufacturer has discovered that their oscillometric blood pressure monitor provides extensive insights into a patient's condition, surpassing the diagnostic capabilities of traditional mercury sphygmomanometers, which only measure systolic and diastolic pressures Additionally, the use of a digital manometer for calibrating sphygmomanometers can enhance accuracy, with potential discrepancies showing a difference of +3.1 mm Hg when compared to a mercury manometer, which can have an accuracy of +6 mm Hg.

Transitioning to non-mercury components in product design poses challenges, as many well-designed products may require significant rethinking to accommodate these alternatives The integration of new designs often comes with a learning curve and the potential for glitches or unintended outcomes For instance, in an industrial setting, a mercury thermometer was replaced with an alcohol thermometer, initially chosen for its similar size and temperature range However, the alcohol thermometer proved inadequate due to its column separating from jarring impacts Consultation with the supplier later revealed a more suitable alternative that performed effectively, highlighting the importance of careful selection in product replacements.

Fortunately, numerous resources are available to facilitate the transition from mercury components and products, including technical support from manufacturers, online how-to guides, and email lists for sharing questions and answers Additionally, pollution prevention organizations offer valuable guidance Many of these resources are particularly relevant to the healthcare industry, which has been a leader in mercury reduction efforts.

Health Care Without Harm (HCWH) http://www.noharm.org

The HCWH website's mercury section offers extensive resources aimed at minimizing mercury use in healthcare As part of an international initiative, Health Care Without Harm seeks to transform the environmental practices within the healthcare sector.

(HCWH) is comprised of more than 300 organizations in 27 countries and includes major health care systems, regulatory bodies, and industry leaders.

Hospitals for a Healthy Environment (H2E) http://www.h2e-online.org/

H2E aims to educate healthcare professionals on pollution prevention strategies within hospitals and healthcare systems By promoting best practices, model waste management plans, resource directories, case studies, and practical tools, H2E helps minimize waste generation and the use of harmful chemicals This initiative is a collaborative effort led by the American Hospital Association.

Protection Agency, Health Care Without Harm and the American Nurses Association In addition, various state and local resources are active participants in the effort to help hospitals

Two areas of note are the Listserv, an online forum for discussion, and the H2E website’s

 H2E Listserv http://www.h2e-online.org/programs/list.htm

The Hospitals for a Healthy Environment (H2E)

Listserv serves as an essential communication platform for healthcare professionals focused on reducing the volume and toxicity of healthcare waste Across the nation, healthcare facilities are actively engaging in various initiatives, such as launching recycling programs, phasing out mercury-containing devices, and opting for environmentally preferable products.

There are countless opportunities to share questions, answers, and advice through this

 H2E Mercury Resources http://www.h2e-online.org/tools/mercury.htm

The Mercury area of the H2E website includes many resources and links for reducing mercury

One very nice document is the “Mercury Virtual

Elimination Plan”, found at: http://www.h2e- online.org/tools/merc-over.htm

This is a comprehensive how-to guide to help hospitals assess existing mercury sources, develop action plans for elimination, and set up an environmentally preferable purchasing plan non-mercury

Association (NEWMOA) http://www.newmoa.org http://www.newmoa.org/Newmoa/htdocs/prevent ion/mercury/

The NEWMOA website offers valuable resources aimed at assisting states in their goal of "virtual elimination" of mercury, specifically targeting the reduction and removal of mercury from the waste stream.

The Sustainable Hospitals Project (SHP) offers essential technical support to the healthcare sector, focusing on the selection of products and practices that minimize occupational and environmental risks Through

Vincent J Canzanello, MD; Patricia L Jensen, RN; Gary l Schwartz, MD, “Are Aneroid Sphygmomanometers Accurate in Hospital and Clinic Settings?”, Arch Intern Med, 2001;

A recent evaluation at Mayo Clinic in Rochester, Minnesota, assessed the accuracy of aneroid sphygmomanometers used in their hospitals The study concluded that these devices deliver accurate pressure measurements when a proper maintenance protocol is adhered to.

Maine Department of Environmental Protection, (February, 2002) “Mercury in Maine: A Status Report” This report provides an update to the

1997 report on Mercury in Maine and it addresses the Maine mercury reporting requirements enacted in May 2000 Available at: http://www.state.me.us/dep/mercury/hginmerepor t.htm (September, 2002)

Tellus Institute, (July, 2000) “Healthy Hospitals: Environmental Improvements Through

Environmental Accounting” This report examines environmental accounting practices in the health care industry and explores whether environmental accounting is a useful approach for uncovering waste minimization opportunities.The report also considers opportunities for influencing upstream procurement practices and supply chain issues Available at: http://www.epa.gov/opptintr/acctg/pubs/hospitalr eport.pdf (September, 2002)

This report offers a comprehensive global assessment of mercury and its compounds, highlighting strategies to mitigate their significant adverse effects It reviews global efforts to manage mercury releases and reduce exposure, encompassing national initiatives, international agreements, and programs from various organizations Additionally, it outlines sub-regional and regional initiatives, with particular emphasis on sections pertinent to Maine.

8 Prevention and control technologies and practices

9 Initiatives for controlling releases and limiting use and exposure

Appendix Overview of Existing and Future

National Actions, Including Legislation, relevant to mercury; by Region.

Available at: http://www.chem.unep.ch/mercury/WG- meeting1-revised-report-download.htm (October,

Welch Allyn, Inc (January 11, 2000) "Analysis of Different Sphygmomanometer Technologies"

This provides a discussion on the different types of blood pressure devices and their merits and shortcomings Available at:

(http://www.welchallyn.com/medical/support/ma nuals/Tycoswhitepapers.PDF

Welch Allyn, Inc (July 10, 2002) "Calibrating

Your Sphygmomanometer" This describes considerations for routine calibration of sphygmomanometers and describes how digital reference meters can potentially offer a more accurate calibration than mercury references.

Available at: http://www.welchallyn.com/medical/support/man uals/Aneroid%20Calibration%20Memo.pdf (August, 2002)

Online Case Studies & Mercury Videos

Clean Car Campaign, “Switch the Switch”, Driving Forward: Volume 3, March 2002 Available at http://cleancarcampaign.org/pdfs/wol_3%20_Mar ch_2002.pdf (September 2002).

In July 2001, the Delta Institute, in collaboration with Inland Ispat Indiana Harbor Works, Bethlehem Steel Burns Harbor Division, United States Steel Gary Works, and the Lake Michigan Forum, published "A Guide to Mercury Reduction in Industrial and Commercial Settings." This comprehensive guide focuses on strategies for reducing mercury emissions in various industrial environments and is available for download at http://delta-institute.org/Steel-Hg-report-0627011.pdf.

Sustainable Hospitals Project “Mercury Reduction Case Studies”, Available at: http://www.sustainablehospitals.org/HTMLSrc/IP _Merc_CS_Strong.html (September, 2002).

Tellus Institute, (July, 2000) “Healthy Hospitals: Environmental Improvements Through

Environmental Accounting” Appendix B in this report includes a mercury reduction case study at Kaiser Permanente.

United States Environmental Protection Agency,

“Mercury Pollution Prevention in Michigan Hospitals” Available at: http://www.epa.gov/seahome/mercury/src/prevca se.htm (September, 2002).

University of Michigan, Occupational Safety and Environmental Health, “Mercury-Filled

Esophageal Dilators” Available at: http://www.p2000.umich.edu/mercury_reduction/ mr1.htm (September, 2002).

University of Vermont, “Mercury Thermometer Swap” (Lab thermometers) Available at: http://esf.uvm.edu/chemsource/thermoswap/ (September, 2002).

Western Lake Superior Sanitary District, (March,

1997) “Addressing Sources of Mercury: Success Stories” Available at: http://www.wlssd.duluth.mn.us/Blueprint%20for

The Michigan Department of Environmental Quality, Bowling Green University, the Ohio Environmental Protection Agency, and Radar Environmental have collaborated to create two informative video clips demonstrating mercury vapor emissions These short online videos visually depict mercury vapor rising at room temperature from both a petri dish containing elemental mercury and from mercury spilled from a broken fever thermometer onto a carpet For more information, visit http://www.ecosuperior.com/pages/mercuryvapour.html (September 2002).

Maine DEP Letter to Manufacturers of Mercury-added Products

Manufacturers who reported mercury-added products to the Interstate Mercury Education and Reduction Clearinghouse (IMERC) received an information request IMERC, established by the Northeast Waste Management Officials' Association, aims to oversee the enforcement of state laws that restrict the sale of mercury-added products unless manufacturers disclose the mercury content and its intended use States such as Maine, New Hampshire, Connecticut, and Rhode Island have enacted these regulations.

Enclosed please find a copy of An Act to Phase Out the Availability of Mercury-added

Products as recently enacted by the Maine Legislature.

Maine law prohibits the sale or distribution of mercury-added thermostats for most residential and commercial uses after January 1, 2006, while allowing for an exemption process under certain conditions.

Section 2 of the bill mandates the Department to assess information on mercury-added products and develop a comprehensive strategy aimed at reducing their mercury content This strategy is expected to be submitted to the Legislature by next January, where it will likely inform future legislative actions concerning mercury-added products.

The mercury product notification law, enacted last year, serves as a key information source for our efforts Under this law, 38 MRSA §1661-A, the sale of mercury-added products in Maine is prohibited after January 1, 2002, unless manufacturers have reported the quantity and purpose of the mercury to the Department.

To develop an effective strategy, the Legislature needs more information on non-mercury alternatives and manufacturers' plans to eliminate mercury usage Therefore, I invite you to share specific details about your products, which will aid the Department in crafting its strategy Your input will be evaluated alongside research conducted by a consultant that the Department will soon hire.

We are currently investigating mercury-added products (excluding lamps and dental amalgam) that contain over 100 milligrams of mercury, or for formulated items such as cosmetics and cleansers, have a mercury concentration exceeding 50 ppm If you manufacture such products, we encourage you to provide the relevant information.

• Your plan, if any, for reducing or phasing out the use of mercury, including relevant timetables for such reductions or elimination,

• Information bearing on the availability, feasibility and affordability of non-mercury alternatives to the product;

• The public health, environmental or other societal benefits (if any) of continuing to use mercury in the product; and

• Any other information you believe relevant to the development of the Department's strategy.

To comply with the Legislature's January 1, 2003 deadline, we require your information by June 30, 2002, to ensure proper consideration by the Department and its consultant before drafting the document The draft will be ready in early fall, and I can provide it upon request.

Thank you for your help, and please feel free to call me at (207) 287-8556 or email me at Enid.Mitnik@state.me.us if you have questions.

Aneroid Sphygmomanometers

Aneroid sphygmomanometers offer similar cost, technique, and performance to mercury sphygmomanometers Despite this, some healthcare professionals remain reluctant to use aneroid devices due to mixed messages regarding their accuracy and reliability This article aims to clarify common misconceptions surrounding aneroid sphygmomanometers.

What are the concerns about aneroid sphygmomanometers?

Accurate blood pressure measurement is crucial when selecting sphygmomanometers Once properly calibrated, both aneroid and mercury sphygmomanometers from reputable manufacturers perform equally Regular calibration checks and preventive maintenance are essential for all sphygmomanometers Although the calibration procedures differ between mercury and aneroid models, they are similar in frequency, complexity, and the level of care needed Ultimately, both types require distinct calibration techniques but comparable attention to ensure optimal performance.

Medical professionals express concerns about the durability and accuracy of aneroid sphygmomanometers, which can be easily damaged if dropped or bumped, leading to calibration issues In contrast, mercury sphygmomanometers are less prone to such problems due to their rigid mounting requirements, ensuring the mercury column remains perfectly vertical for accurate readings To mitigate concerns about aneroid devices, it is advisable to opt for wall-mounted or mobile stand models, similar to mercury devices, instead of portable options Additionally, one manufacturer has addressed these durability issues by introducing a gear-free aneroid sphygmomanometer designed to withstand falls from up to 30 inches while maintaining accuracy.

Sphygmomanometers undergo extensive testing and evaluation before entering the market, with those sold in the United States requiring approval from the Food and Drug Administration (FDA) The FDA mandates that companies demonstrate substantial equivalence to existing models and validate accuracy through clinical studies Additionally, the FDA recognizes the ANSI/AAMI SP-9 voluntary standard, which outlines performance criteria for both aneroid and mercury sphygmomanometers, addressing functionality, accuracy, and safety through specific requirements and suggested compliance tests.

Several hospitals across the United States, including those in Maine such as Eastern Maine Medical Center, General Health, Mercy Hospital, Mid Coast Hospital, St Andrew’s Hospital, and Southern Maine Medical Center, have successfully eliminated mercury sphygmomanometers A recent survey revealed that four of these hospitals found the alternatives to perform satisfactorily Additionally, many other hospitals are in the process of phasing out mercury devices, reflecting a growing trend towards safer medical practices.

Routine maintenance is essential for both mercury and aneroid sphygmomanometers to ensure accurate readings For mercury gauges, it is crucial to verify and adjust the zero level, replace the air filter, ensure the column is perpendicular and vertical, check for mercury oxidation that may hinder visibility, and clean the tube if needed In contrast, aneroid gauges require checking the needle for smooth rotation and testing their accuracy at various intervals against a reference meter.

Hospitals utilizing mercury sphygmomanometers must ensure proper maintenance and calibration of the devices, while also being equipped to safely manage mercury handling and spills This includes having trained personnel available 24/7 to respond to any mercury spills, access to a mercury spill kit, and hazardous waste resources for effective decontamination and removal of mercury Additionally, hospitals need to allocate financial resources for spill response efforts and address any liability related to mercury exposure.

Group Purchasing Organizations (GPOs) are taking proactive steps to promote pollution prevention Premier, a healthcare alliance comprised of over 200 independent hospitals and healthcare systems across the United States, has made a significant commitment by banning the inclusion of mercury-containing products in their group contracts, except when no suitable alternatives are available As a result, mercury sphygmomanometers will no longer be available through Premier's offerings.

Consorta, Inc, (a cooperative health care resource management and GPO, whose shareholders are

Catholic-sponsored, faith-based or non-profit health systems) also has an effort underway to obtain shareholder approval to take mercury containing medical devices off their contracts

American Heart Association: “The aneroid manometer is also widely used and can provide accurate measurements if properly calibrated”. (Perloff et al)

The American Heart Association emphasizes the importance of handling mercury manometers with care due to the potential toxic effects of mercury spills In high-traffic areas, their use is discouraged to minimize the risk of accidental spills, highlighting the need for safety precautions in environments where such incidents are more likely to happen.

American Medical Association: “When in proper functioning condition, both mercury and aneroid sphygmomanometers are acceptable instruments for blood pressure measurement.” (Bailey and Bauer)

The American Medical Association emphasizes the importance of regularly examining mercury column manometers to prevent inaccuracies in blood pressure measurements It warns clinicians against becoming complacent about the reliability of these instruments Additionally, a working meeting on blood pressure measurement reassures that transitioning from mercury manometers to manual aneroid devices poses no risk, provided there is proper validation, calibration, and ongoing maintenance of the equipment.

Richard H Bailey and John H Bauer, “A review of common errors in the indirect measurement of blood pressure sphygmomanometry”, Archives of

This article examines three key sources of error in indirect blood pressure measurement: observer bias, equipment issues, and the absence of standardized measurement protocols It highlights how these factors can impact the accuracy of blood pressure readings and discusses effective techniques for ensuring proper blood pressure measurement.

EPA Region 1 Mercury Challenge Program http://www.epa.gov/region01/assistance/neeat/m ercury/Directory2000.pdf (accessed 1/13/03) http://www.epa.gov/region1/pr/2001/apr/010428.html (accessed 1/13/03)

Tiêu đề	An Investigation of Alternatives to Mercury Containing Products
Tác giả	Catherine Galligan, Gregory Morose, Jim Giordani
Trường học	Lowell Center for Sustainable Production
Thể loại	report
Năm xuất bản	2003

Định dạng
Số trang	86
Dung lượng	1,13 MB