Hazardous Chemicals Handbook 2 Episode 12 doc

First aid In Great Britain the Health and Safety (First Aid) Regulations 1981 require an employer to provide such equipment and facilities as are adequate and appropriate in the circumstances to enable first aid to be rendered to his employees if they are injured, or become ill, at work. An Approved Code of Practice gives more specific details on the number of first-aid personnel and their training, and the type of equipment. Emergency first aid A qualified first-aider, or nurse, should be called immediately to deal with any injury – however slight – incurred at work. Any person on the spot may have to act immediately to provide first-aid treatment to prevent deterioration in the injured person’s condition until assistance arrives. The aims are: • To sustain life. • To minimize danger. • To relieve pain and distress. Check the situation for danger to rescuers, then act as follows: The patient: is in danger Remove from danger, or remove the danger from the patient is not breathing If competent to do so, give artificial ventilation. Otherwise send for help without delay has no pulse Start cardiac compressions is bleeding Stop bleeding Table 13.7 Procedure to treat spillages in a laboratory Instruct others to keep a safe distance Remove contaminated clothing and wash the hands before putting on protective clothing Shut off all sources of ignition (for spillage of flammable fluid); do not operate electric switches in the vicinity Ventilate the area well (for at least 10 min) to reduce irritant vapours and biological aerosols, and to evaporate remaining liquid (bear in mind that ventilation may transfer the danger to other parts of the premises) Areas with sealed windows should have controlled ventilation (areas that cannot be adequately ventilated are unsuitable for use with hazardous materials) Turn off the source of the leak and limit the spread of fluid by means of mop, dusters, rags, sand or diversion Absorb spillage and shovel into buckets, and remove to a safe place, dilute greatly with running water and/or dilute with dispersing agent and water (as with ammonia solution, ethanol, methanol and formaldehyde solution) Neutralize acid with soda ash, chalk or similar materials kept for the purpose, mop up cautiously with water (in case local areas of concentrated acid have been missed) Use hypochlorite solutions in excess scattered over spillage of cyanide solutions and wearing respirator and gloves, mop up and collect in buckets. Allow to stand for 24 hours before diluting greatly and running to waste Flood with a phenolic disinfectant any biologically contaminated area for 30 to 60 min and then clean up with water and allow to dry. After cleaning up wash hands with a suitable skin disinfectant (such as 0.5% Chlorhexidine in 70% methylated spirit) Use forceps or a brush and pan with broken glass; never use the fingers, even with gloves. Disinfect broken glass arising from biological spills Dispose of, by special arrangements, chemicals which cannot be admitted to the public sewerage system, e.g. flammable liquids and reagents with high toxicity FIRST AID 429 430 OPERATING PROCEDURES is unconscious Check the mouth for any obstruction. Open the airway by tilting the head back and lifting the chin using the tips of two fingers. If this does not keep the airway open, turn the casualty into the recovery position i.e. turn on side and ensure they cannot roll over; lift the chain feels faint Lie him or her down has broken bones Immobilize. Do not move the patient unless he/ she is in a position which exposes them to immediate danger. Obtain expert help has open wounds After washing your hands, if possible cover with a dressing from the first-aid box. Seek appropriate help has thermal or chemical burns Immerse or flood copiously with cold water for ≥10 min has minor injuries Ignore these if there are more serious ones is poisoned Small amounts of water may be administered, more if the poison is corrosive. Administer a specific antidote if one exists. Do not induce vomiting. Cuts All minor cuts should be cleaned thoroughly and covered with a suitable dressing. After controlling bleeding, if there is a risk of a foreign body in the wound do not attempt to remove it, but cover loosely and take patient to a doctor or hospital, as should be done if there is any doubt about the severity of the wound. Burns/scalds Burns may arise from fire, hot objects/surfaces, radiant heat, very cold objects, electricity or friction. Scalds may arise from steam, hot water, hot vapour or hot or super-heated liquids. The affected area should be cooled by holding in cold, clean running water. Swelling is liable to occur so jewellery or clothing likely to cause constriction must be removed. The area should then be covered with a sterile dressing, care being taken to apply the dressing without it sticking to the burned area. Blisters should not be pricked or damaged and cream or lotions should be avoided. The patient may suffer from shock, in proportion to the extent of the injury. Give small drinks and keep warm: do not overheat. In all cases, speed of treatment is crucial to limit the effects of burns. Flowcharts which summarize the initial procedures for electrical, thermal and chemical burns respectively are shown in Figure 13.5. Chemical splashes, poisoning by ingestion Refer to Table 13.8. All cases of ingestion should be referred to a doctor and/or hospital without delay. Antidotes Effective antidotes for use in an emergency are not common. Examples include: * Material Safety Data Sheets should accompany casualty in every case. Chemical burns Protect yourself with rubber gloves, etc. Identify, but do not try to neutralize, the chemical Remove casualty from danger Wet chemicals Dry chemicals Carefully brush off chemical Remove contaminated clothes, jewellery, boots, etc. Wash/shower all affected areas with water for at least 10 minutes Do not use ointments Seek medical attention* Work’s medical centre Own GP Hospital casualty Thermal burns Remove casualty from heat or cold Wash/shower all affected areas with water for at least 10 minutes Minor – simple burns Major • large, deep • other injuries Continue with cold water until pain stops Seek urgent medical attention Advise casualty to seek medical attention Work’s medical centre Own GP Hospital casualty Do not use ointments Turn off power or isolate casualty from current Electrical burns Treat for thermal burns – more than one burn site may be present Always refer for immediate medical assessment Work’s medical centre Hospital casualty Figure 13.5 Initial procedures for dealing with burn injuries (a) (b) (c) FIRST AID 431 432 OPERATING PROCEDURES • for cyanide poisoning. Intravenous injection of: – 3% Sodium nitrite and 50% sodium thiosulphate. – Cobalt EDTA. • for HF on the skin. Application of magnesium oxide paste with injection of calcium gluconate below the affected area. • for splashes of phenols. Apply alcohol-soaked swabs. Where there is a specific antidote suitable for emergency use it should be kept available and appropriate personnel trained in its use. Specific training should be given to first-aiders over and above their general training if they may need to administer oxygen or deal with incidents involving hydrogen cyanide, hydrofluoric acid or other special risks. Table 13.8 Standard first aid treatments for chemical exposure Splashes on the skin Flood the splashed surface thoroughly with large quantities of running water for ≥10 min or until satisfied that no chemical remains in contact with the skin Use soap to help remove splashes of solvents, solutions and chemicals known to be insoluble in water Remove all contaminated clothing, taking care not to contaminate yourself in the process If necessary, arrange for transport to hospital or refer for medical advice to nearest doctor Information to accompany the casualty: Chemical involved Details of treatment already given ( Special procedures apply to certain chemicals, e.g. anhydrous hydrogen fluoride, aqueous hydrofluoric acid, phenol and related compounds ) Splashes in the eye Flood the eye thoroughly with large quantities of clean, cool water or sterile liquid from a sealed container and continue for 10–15 min Ensure that the water bathes the eyeball by gently prising open the eyelids and keeping them apart until treatment is completed. Do not attempt to remove anything that is embedded All eye injuries from chemicals require medical advice. Apply an eye pad and arrange transport to hospital Information to accompany the casualty: Chemical involved Details of treatment already given Inhalation of gas Remove the casualty from the danger area after first ensuring your own safety Loosen clothing; administer oxygen if available If the casualty is unconscious, place in the recovery position and watch to see if breathing stops If breathing has stopped, apply artificial respiration by the mouth-to-mouth method; if no pulse is detectable, start cardiac compressions If necessary, arrange transport to hospital Information to accompany the casualty: Gas involved Details of treatment already given ( Special procedures apply to certain chemicals, e.g. hydrogen cyanide) Ingestion of poisonous chemical If the chemical has been confined to the mouth, give large quantities of water as a mouthwash; ensure that the mouthwash is not swallowed If the chemical has been swallowed, small amounts of water may be administered, more if the chemical is corrosive; administer a specific antidote if one exists Do not induce vomiting Arrange transport to hospital Information to accompany the casualty: Chemical swallowed Details of treatment already given Estimate of quantity/concentration of chemical consumed Records Any injuries or cases of illness treated should be recorded. The minimum details are: • Date, time and place of incident/treatment. • Name and job of casualty. • Details of injury/illness and of treatment. • Subsequent movements of casualty (i.e. returned to work, sent home, sent to hospital, etc.). • Name and signature of person providing treatment. Personal protection Because personal protection is limited to the user and the equipment must be worn for the duration of the exposure to the hazard, it should generally be considered as a last line of defence. Respiratory protection in particular should be restricted to hazardous situations of short duration (e.g. emergencies, maintenance, or temporary arrangements while engineering control measures are being introduced). Occasionally, personal protection may be the only practicable measure and a legal requirement. If it is to be effective, its selection, correct use and condition are of paramount importance. (Therefore within the UK the Personal Protective Equipment at Work Regulations 1992 require the provision of suitable p.p.e. except where and to the extent that a risk to health and safety is adequately controlled by other means. This has to be maintained, which covers: replacement or cleaning and keeping in an efficient state, in efficient working order and in good repair.) Respiratory protection Recommendations for the selection, use and maintenance of respiratory protective equipment are provided in the UK by BS 4275 1997 and BS EN 132. The two basic principles are: • purification of the air breathed (respirator) or • supply of oxygen from uncontaminated sources (breathing apparatus). If the oxygen content of the contaminated air is deficient (refer to page 72), breathing apparatus is essential. The degree of protection required is determined by the level of contamination, the hygiene standard for the contaminant(s), the efficiency of any filter or adsorber available, and the efficiency with which the facepiece of the device seals to the user’s face (this is reduced by beards, spectacles etc.). The level of comfort and user acceptability are further considerations. The nominal protection factor (NPF) describes the level of protection afforded by a specific respirator: NPF = Concentration of contaminant in air Concentration of contaminant inside facepiece The British Standard also uses the Assigned Protection Factor, i.e. the level of respiratory protection that can realistically be expected to be achieved in the workplace by 95% of adequately trained and supervised workers, using a properly functioning and correctly fitted respiratory protective device (see Table 13.9) PERSONAL PROTECTION 433 434 OPERATING PROCEDURES Table 13.9 Assigned Protection Factors for Respirators and Breathing Apparatus Type APF (depending upon detailed equipment specification 1 Filtering devices 4–40 Half or quarter mask and filter Filtering half-mask without inhalation valves Valved filtering half masks Filtering half masks Full face mask and filter Power assisted filtering device with full, half or quarter masks Power filtering device with helmet or hood 2 Breathing apparatus 10–2000 Light duty construction air line Fresh air hose and compressed air line Self contained Gas masks (canister or cartridge mask) Respirators for gases and vapours comprise a facepiece and a container filled with a specific adsorbent for the contaminant. Care must be taken to select the correct type. More than one canister can be attached. The useful life of a canister should be estimated based on the probable concentration of contaminant, period of use, breathing rate and capacity of the canister. Dust and fume masks Dust and fume masks consist of one or two cartridges containing a suitable filter (e.g. paper or resin-impregnated wool) to remove particulate contaminant. The efficiency of the filters against particles of various sizes is quoted in manufacturers’ literature and national standards. Such masks do not remove vapour from the air. Facepiece fit is the limiting factor on the degree of protection afforded. Efficiency tends to increase with use, i.e. as the filter becomes loaded, but the resistance to breathing also increases. ‘Paper cup’ type masks are also available. Powered dust masks Masks are available with battery-powered filter packs which supply filtered air to a facepiece from a haversack filter unit. Another type comprises a protective helmet incorporating an electrically operated fan and filter unit complete with face vizor and provision for ear muffs. Breathing apparatus Compressed airline system: a facepiece or hood is connected to a filter box and hand-operated regulator valve which is provided with a safety device to prevent accidental complete closure. Full respiratory, eye and facial protection is provided by full-facepiece versions. The compressed air is supplied from a compressor through a manifold or from cylinders. Self-contained breathing apparatus is available in three types: • Open-circuit compressed air. • Open-circuit oxygen-cylinder, liquid or solid-state generation. • Regenerative oxygen. All respiratory protective systems should be stored in clean, dry conditions but be readily accessible. They should be inspected and cleaned regularly, with particular attention to facepiece seals, non- return valves, harnesses etc. Issue on a personal basis is essential for regular use; otherwise the equipment should be returned to a central position. Records are required of location, date of issue, estimated duration of use of canisters etc. Guidance on the choice of respiratory protection for selected environments is given in Figure 13.6. All persons liable to use such protection should be fully trained; this should cover details of hazards, limitations of apparatus, inspection, proper fitting of facepiece, testing, cleaning etc. Toxic Low toxicity Environment Confined spaces e.g. tanks, stills Allowing unrestricted movement Allowing limited movement DG G HAZARDS All hazards All hazards CBAABA APPARATUS CRHDR HDH CBA PDR PPD GDR CAR or CBA CR CPF or CBA Low toxicity Toxic Low toxicity Toxic Normal working conditions Allowing unrestricted movement DG D G OD D OD Figure 13.6 Guide to the selection of respiratory protection Hazards Equipment D Dust ABA Air line breathing apparatus G Gas CAR Canister respirator DG Dust and gas CBA Self-contained breathing apparatus OD Oxygen deficiency CPF Canister respirators with particulate filters CR Cartridge respirator GDR General purpose dust respirators HDH High efficiency dust respirators HDR Positive pressure direct dust hoods and blouses (high efficiency) PDR Positive pressure powered dust respirators PPD Positive pressure powered dust hood and blouses Eye protection The common-sense approach to the use of eye protection, includes: • Eye protectors and/or fixed shields provided according to the nature of the process. • Eye protectors on personal issue. • Replacement of lost, defective or unsuitable eye protectors. • Eye protectors suitable for individual needs. • Eye protectors and shields that conform to an appropriate, approved specification and are marked to indicate intended use. PERSONAL PROTECTION 435 436 OPERATING PROCEDURES There are also requirements relating to the proper use and care of eye protectors/shields. The normal range of personal eye protection is summarized in Table 13.10. In the UK the appropriate standard is BS EN 167, 168, 175 and BS 7028. Fixed shields can be of polycarbonate plastic to guard against splashing and projectiles, or of toughened glass or Perspex for protection against splashing only. Wrap-around of the hazard is required. If the need for access behind a shield cannot be eliminated personal protection is still necessary. Table 13.10 Normal range of personal eye protection Safety spectacles A variety of styles and colours are available with different side-shields to protect against lateral hazards Attention must be given to both the lens (available toughened/tinted/to personal prescription for wearers requiring corrected vision) and the frame Cup and wide-vision goggles Tend to be more versatile and cheaper and offer more protection and, according to design, can protect against fine dust, fumes, liquid splashes and impact from flying particles Tend to be less comfortable than safety glasses and usually cannot be worn over ordinary spectacles Often mist up and as a rule are not fitted with prescription lenses Face shields Intended to protect from the forehead to the neck Some are attached to headgear and equipped with a chin-guard to prevent upward splashing of acids/alkalis The transparent screen is commonly made of polycarbonate Heavier special versions are available, e.g. for welding Head protection Head protection is required against falling objects but also serves against heat, chemical splashes, or entanglement of hair in machinery. The appropriate standard is BS EN 397 (1995). Common-sense guidelines can be deduced from the requirements for ‘building operations’ and ‘works of engineering construction’ summarized in Table 13.11. In special situations, e.g. for fire- fighting or protection against toxic chemicals, hoods and suits cover the head and neck and many incorporate protection. Table 13.11 Head protection requirements for construction activities (Construction (Head protection) Regulations 1989) Provision, maintenance and replacement whenever necessary Regular checking/replacement Protection to be adequate, e.g. to BS EN 397 or equivalent standard (Type 1 helmets with comfort options strongly recommeded) Protection to be compatible with the work/activity of the wearer Protection to be worn at all times unless there is no risk from falling objects or possibility of hitting the head against something Wearing of safety helmets to be ensured Hand protection Protection of the hands may rely upon gloves or barrier creams. The choice of gloves depends upon: • Hazard to be protected against, e.g. corrosive or irritant chemicals, heat, abrasion. • Degree of resistance required. • Sensitivity required. • Area to be protected, e.g. to wrist level or extending over the forearms. For applications where surgical gloves provide adequate protection, if these are of natural rubber latex then powder-free gloves with low/undetectable protein and allergen levels are advisable. (Alternatively the use of nitrile gloves eliminates the risk of latex allergy.) General advice on the suitability and degree of resistance of glove materials are summarized in Table 13.12. In all cases, however, in addition to the necessary mechanical properties (i.e. resistance to abrasion, blade cut resistance, tear resistance and puncture resistance rated according to European Standard EN 388), consideration should be given to the resistance to the specific chemicals involved. Chemical permeation is rated in tests under EN 374-3. The breakthrough time of a chemical through a glove is quoted as a permeation index: Breakthrough time (min) Greater than 10 30 60 120 240 480 Permeation index 1 2 3 4 5 6 If the time <10 minutes the index is 0. Clearly the greater the index the better the resistance to permeation. Some glove suppliers also provide data on, or a noting of, degradation, i.e. the physical effects which a chemical will have upon a particular glove material. Resistance to penetration by micro-organisms is covered by EN 374-2 and protection from low temperatures in EN 511. Careful handling and regular inspection are essential since chemicals and abrasion will eventually cause deterioration of gloves. Rinsing in clean water and drying naturally will prolong their life. Barrier creams are applied before work to provide a protective film. A different type of cream, cleansing cream, is applied after work to aid dirt removal and to condition skin with humectant. Limitations of barrier creams • They may become a reservoir for harmful chemicals. • Water-soluble preparations should not be used for aqueous situations; water-repellant creams are available for such applications. • There is a limit to the quantity of chemical a barrier cream can repel. • Effectiveness diminishes as a result of abrasion and massage. • They are unlikely to prevent an allergic contact dermatitis. Protective clothing Protective clothing includes overalls, bibs, duffle coats, aprons, complete one-piece suits with hoods, spats, armlets etc. It is chosen for protection against mechanical hazards, abrasion, extremes of temperature etc. as well as chemicals. The nature of the hazard and user comfort dictate the choice. The properties of a range of protective clothing materials are listed in Table 13.13. Further guidance on selection, use and maintenance of chemical protective clothing is given in BS 7184:1989. PERSONAL PROTECTION 437 438 OPERATING PROCEDURES Table 13.12 Glove material resistance rating (courtesy James North & Sons Ltd) Glove material Chemical Natural rubber Neoprene Nitrile Normal PVC High grade PVC Organic acids Acetic acid E E E E E Citric acid E E E E E Formic acid E E E E E Lactic acid E E E E E Lauric acid E E E E E Maleic acid E E E E E Oleic acid E E E E E Oxalic acid E E E E E Palmitic acid E E E E E Phenol E E G E E Propionic acid E E E E E Stearic acid E E E E E Tannic acid E E E E E Inorganic acids Arsenic acid G G G E E Carbonic acid G G G E E Chromic acid (up to 50%) G F F E (1) G Fluorosilicic acid G G G E G Hydrochloric acid (up to 40%) G G G E G Hydrofluoric acid G G G E (1) G Hydrogen sulphide (acid) F F G E E Hydrogen peroxide G G G E E Nitric acid (up to 50%) NR NR NR G (1) F (1) Perchloric acid F G F E (1) G Phosphoric acid G G G E G Sulphuric acid (up to 50%) G G F E (1) G Sulphurous acid G G G E E Saturated salt solutions Ammonium acetate E E E E E Ammonium carbonate E E E E E Ammonium lactate E E E E E Ammonium nitrate E E E E E Ammonium nitrite E E E E E Ammonium phosphate E E E E E Calcium hypochlorite NR G G E E Ferric chloride E E E E E Magnesium chloride E E E E E Mercuric chloride G G G E E Potassium chromate E E E E E Potassium cyanide E E E E E Potassium dichromate E E E E E Potassium halides E E E E E Potassium permanganate E E E E E Sodium carbonate E E E E E Sodium chloride E E E E E Sodium hypochlorite NR F F E E Sodium nitrate E E E E E Solutions of copper salts G G G E E Stannous chloride E E E E E Zinc chloride E E E E E Alkalis Ammonium hydroxide E E E E E Calcium hydroxide E E E E E Potassium hydroxide E G G E E [...]... 14.1 shows the label for Class 1, Division 1.1, 1 .2 or 1.3 explosive EXPLOSIVE Figure 14.1 Example of label for explosive (Division 1.1, 1 .2 or 1.3) 448 MARKETING Table 14.3 ‘Risk’ phrases from the Approved List 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 Explosive when dry Risk... liberating extremely flammable gases 15 /29 Contact with water liberates toxic, extremely flammable gas 20 /21 Harmful by inhalation and in contact with skin 20 /21 /22 Harmful by inhalation, in contact with skin and if swallowed 20 /22 Harmful by inhalation and if swallowed 21 /22 Harmful in contact with skin and if swallowed 23 /24 Toxic by inhalation and in contact with skin 23 /24 /25 Toxic by inhalation, in contact... environment Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment Table 14.4 ‘Safety’ phrases from the Approved List 1 2 3 4 5 6 7 8 9 12 13 14 15 16 17 18 20 21 22 23 24 25 26 27 28 29 30 33 35 36 37 38 39 40 41 42 43 45 46 47 48 49 50 51 Keep locked up Keep out of reach of children Keep in a cool place Keep away from living quarters Keep contents under (appropropriate... skin and if swallowed 48 /22 Harmful: danger of serious damage to health by prolonged exposure if swallowed 48 /23 Toxic: danger of serious damage to health by prolonged exposure through inhalation 450 MARKETING Table 14.3 Cont’d 48 /23 /24 48 /23 /24 /25 48 /23 /25 48 /24 48 /24 /25 48 /25 50/53 51/53 52/ 53 Toxic: danger of serious damage to health by prolonged exposure through inhalation and in contact with skin... 23 /24 /25 Toxic by inhalation, in contact with skin, and if swallowed 23 /25 Toxic by inhalation and if swallowed 24 /25 Toxic in contact with skin and if swallowed 26 /27 Very toxic by inhalation and in contact with skin 26 /27 /28 Very toxic by inhalation, in contact with skin and if swallowed 26 /28 Very toxic by inhalation and if swallowed 27 /28 Very toxic in contact with skin and if swallowed 36/37 Irritating... inhalation 40 /20 /21 Harmful: possible risk of irreversible effects through inhalation and in contact with skin 40 /20 /21 /22 Harmful: possible risk of irreversible effects through inhalation in contact with skin and if swallowed 40 /20 /22 Harmful: possible risk of irreversible effects through inhalation and if swallowed 40 /22 Harmful: possible risk of irreversible effects if swallowed 40 /21 Harmful: possible... contact with skin 40 /21 /22 Harmful: possible risk of irreversible effects in contact with skin and if swallowed 42/ 43 May cause sensitization by inhalation and skin contact 48 /20 Harmful: danger of serious damage to health by prolonged exposure through inhalation 48 /20 /21 Harmful: danger of serious damage to health by prolonged exposure through inhalation and in contact with skin 48 /20 /21 /22 Harmful: danger... in contact with skin and if swallowed 48 /20 /22 Harmful: danger of serious damage to health by prolonged exposure through inhalation and if swallowed 48 /21 Harmful: danger of serious damage to health by prolonged exposure in contact with skin 48 /21 /22 Harmful: danger of serious damage to health by prolonged exposure in contact with skin and if swallowed 48 /22 Harmful: danger of serious damage to health... 39 /23 Toxic: danger of very serious irreversible effects through inhalation 39 /23 /24 Toxic: danger of very serious irreversible effects through inhalation and in contact with skin 39 /23 /24 /25 Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed 39 /23 /25 Toxic: danger of very serious irreversible effects through inhalation, and if swallowed 39 /24 ... contact with skin 39 /24 /25 Toxic: danger of very serious irreversible effects in contact with skin and if swallowed 39 /25 Toxic: danger of very serious irreversible effects if swallowed 39 /26 Very toxic: danger of very serious irreversible effects through inhalation 39 /26 /27 Very toxic: danger of very serious irreversible effects through inhalation and in contact with skin 39 /26 /27 /28 Very toxic: danger . explosive peroxides 20 . Harmful by inhalation 21 . Harmful in contact with skin 22 . Harmful if swallowed 23 . Toxic by inhalation 24 . Toxic in contact with skin 25 . Toxic if swallowed 26 . Very toxic. glove is quoted as a permeation index: Breakthrough time (min) Greater than 10 30 60 120 24 0 480 Permeation index 1 2 3 4 5 6 If the time <10 minutes the index is 0. Clearly the greater the index. inhalation 27 . Very toxic in contact with skin 28 . Very toxic if swallowed 29 . Contact with water liberates toxic gas 30. Can become highly flammable in use 31. Contact with acids liberates toxic gas 32.