/home/gencode/cen/bsen1233/en1233 1 1453 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |[.]
BRITISH STANDARD Water quality Ð Determination of chromium Ð Atomic absorption spectrometric methods The European Standard EN 1233 : 1996 has the status of a British Standard ICS 13.060.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BS EN 1233 : 1997 BS 6068 : Section 2.38 : 1997 Confirmed July 2008 BS EN 1233 : 1997 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EH/3, Water quality, to Subcommittee EH/3/2, Physical, chemical and biochemical methods, upon which the following bodies were represented: British Agrochemicals Association Ltd British Ceramic Research British Gas plc British Soft Drinks Association Ltd Chemical Industries' Association Convention of Scottish Local Authorities Department of the Environment (Water Directorate) Environment agency GAMBICA (BEAMA Ltd.) Industrial Water Society Laboratory of the Government Chemist Royal Society of Chemistry Soap and Detergent Industry Association Society of Chemical Industry Swimming Pool and Allied Trades Association Ltd Water Companies Association Water Research Centre Water Services Association of England and Wales This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15 January 1997 BSI 1997 The following BSI references relate to the work on this standard: Committee reference EH/3/2 Draft for comment 93/508225 DC ISBN 580 26789 X Amendments issued since publication Amd No Date Text affected BS EN 1233 : 1997 Contents Page Committees responsible Inside front cover National foreword ii Foreword Method Introduction Scope Normative references 3 Determination of chromium by flame atomic absorption spectrometry Determination of chromium by electrothermal atomization atomic absorption spectrometry Annex A (informative) Information on pretreatment and digestion of sludge and sediment samples Tables Precision data for clause Interfering ions Precision data for clause BSI 1997 i BS EN 1233 : 1997 National foreword This British Standard has been prepared by Technical Committee EH/3 and is the English language version of EN 1233 Water quality Ð Determination of chromium Ð Atomic absorption spectrometric methods, published by the European Committee for Standardization (CEN) It supersedes BS 6068 : Section 2.38 : 1990, which is withdrawn NOTE The tests described in this British Standard should only be carried out by suitably qualified persons with an appropriate level of chemical expertise Standard chemical procedures should be followed throughout Cross-references Publication referred to EN 25667-2 : 1993 ISO 5667-3 : 1994 Corresponding British Standard BS 6068 Water quality Part Sampling Section 6.2 : 1991 Guidance on sampling techniques Section 6.3 : 1996 Guidance on the preservation and handling of samples Compliance with a British Standard does not of itself confer immunity from legal obligations ii BSI 1997 EN 1233 EUROPEAN STANDARD NORME EUROPÊENNE EUROPẰISCHE NORM July 1996 ICS 13.060.40 Descriptors: water, quality, chemical analysis, determination of content, chromium, atomic absorption spectrometry English version Water quality Ð Determination of chromium Ð Atomic absorption spectrometric methods Qualite de l'eau Ð Dosage du chrome Ð MeÂthodes par spectromeÂtrie d'absorption atomique Wasserbeschaffenheit Ð Bestimmung von Chrom Ð Verfahren mittels Atomabsorptionsspektrometrie This European Standard was approved by CEN on 1996-05-16 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comite EuropeÂen de Normalisation EuropaÈisches Komitee fuÈr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members Ref No EN 1233 : 1996 E Page EN 1233 : 1996 Foreword This European Standard has been prepared by the Technical Committee CEN/TC 230, Water analysis, the Secretariat of which is held by DIN Annex A is informative This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 1997, and conflicting national standards shall be withdrawn at the latest by January 1997 In accordance with the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom On the elaboration of this European Standard, the revision of the International Standard ISO 9174 has been started simultaneously with the intention to harmonize both standards BSI 1997 Page EN 1233 : 1996 Introduction Chromium occurs in water in the oxidation states III and VI The two methods described determine chromium in both oxidation states, either as acid soluble chromium or as water soluble chromium, depending on the sample pretreatment The method chosen depends on the concentration of chromium in the water to be examined Some information is given in an informative annex on pretreatment and digestion of chromium from sludges and sediments Scope This European Standard specifies two methods for the determination of chromium in water by atomic absorption spectrometry The two methods are covered in separate clauses as follows: ± clause 3: Determination of chromium by flame atomic absorption spectrometry; ± clause 4: Determination of chromium by electrothermal atomization atomic absorption spectrometry Clause is applicable to the analysis of water and waste water when the concentration range is between 0,5 mg/l and 20 mg/l of chromium When the concentration is below 0,5 mg/l, the determination can be carried out after carefully evaporating an acidified sample to small volume, taking care to avoid the formation of a precipitate WARNING: The use of evaporation will increase the effect of interfering substances and therefore for concentrations below 0,1 mg/l the method in clause is given Clause is applicable to the analysis of water and waste water when the concentration range is between mg/l and 100 mg/l of chromium by injecting a sample volume of 20 ml It is applicable to the determination of higher concentrations by using a smaller sample volume Normative references This European Standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references the latest edition of the publication referred to applies EN 25667-2 : 1993 Water quality Ð Sampling Ð Part 2: Guidance on sampling techniques (ISO 5667-2 : 1991) EN ISO 5667-3 : 1995 Water quality Ð Sampling Ð Part 3: Guidance on the preservation and handling of samples (ISO 5667-3 : 1994) Determination of chromium by flame atomic absorption spectrometry 3.1 Principle The method is based on the atomic absorption spectrometric measurement of the chromium content of the acidified sample in a nitrous oxide/acetylene flame Measurement at a wavelength of 357,9 nm Addition of lanthanum salt to reduce matrix interferences is necessary 3.2 Reagents 3.2.1 General All reagents shall be of recognized analytical grade Use deionized water or water distilled from an all glass apparatus The water used for blank tests and for preparing reagents and standard solutions shall have a chromium content that is negligible compared with the smallest concentrations to be determined in the samples 3.2.2 Hydrochloric acid, HCl, r ≈ 1,18 g/ml 3.2.3 Nitric acid, HNO3, r ≈ 1,42 g/ml 3.2.4 Nitric acid, c(HNO3) = 1,5 mol/l Introduce about 500 ml of water into a 1000 ml volumetric flask, add 100 ml of nitric acid (see 3.2.3) and dilute to the mark with water 3.2.5 Hydrogen peroxide, H2O2,30 % (m/m) solution 3.2.6 Lanthanum chloride, (LaCl3), solution with r(La) = 20 g/l Dissolve 23,5 g of lanthanum oxide La2O3, in 200 ml of hydrochloric acid (see 3.2.2), dilute to 1000 ml with water and mix Appropriate precautions shall be observed when preparing this solution because the reaction of La2O3 with hydrochloric acid is strongly exothermic 3.2.7 Chromium solutions 3.2.7.1 Chromium, stock solution, with r(Cr) = 1,000 g/l Dry a portion of potassium dichromate (K2Cr2O7) at 105 ÊC ± ÊC for about h Cool and dissolve 2,825 g ± 0,001 g of the dried potassium dichromate in water Add ml ± ml of nitric acid (see 3.2.3) and dilute to 1000 ml with water in a volumetric flask ml of this stock solution contains 1,00 mg of chromium Store this solution in either polyethene or borosilicate glass containers at room temperature The solution is stable at room temperature for about year if it is stored in the dark and at a pH between and NOTE Chromium stock solutions are commercially available BSI 1997 Page EN 1233 : 1996 3.2.7.2 Chromium, standard solution with r(Cr) = 50 mg/l Introduce 50,00 ml ± 0,01 ml of the chromium stock solution (see 3.2.7.1) into a 1000 ml volumetric flask Add ml of nitric acid (see 3.2.3), make up to the mark with water and mix This solution is stable for at least month 3.3 Apparatus 3.3.1 Atomic absorption spectrometer, equipped with a chromium hollow cathode lamp and a nitrous oxide/acetylene burner, and operated in accordance with the manufacturer's instructions It is essential that the manufacturer's safety recommendations are strictly observed when using the nitrous oxide/acetylene flame 3.3.2 Glassware Before use, carefully soak all glassware for about 24 h in nitric acid (see 3.2.4), then rinse thoroughly with water If low concentrations are expected (for example in ground water), the glassware should be kept under nitric acid (see 3.2.4) until use Do not use glassware which has been cleaned with chromic acid 3.3.3 Membrane filters, of nominal pore diameter 0,45 mm, washed thoroughly with nitric acid (see 3.2.4) and rinsed with water (see 3.2.1) 3.4 Sampling and preparation of test portions 3.4.1 General Collect and preserve samples according to EN 25667-2 and EN ISO 5667-3 See also annex A Collect samples in high density polyethene or borosilicate glass containers which have been previously cleaned with nitric acid (see 3.2.4) and then rinsed with water (see 3.2.1) 3.4.2 Acid soluble chromium Treat the samples by addition of sufficient nitric acid (see 3.2.3), immediately after collection, to adjust the pH to between and To 90 ml of the acidified sample, or another suitable aliquot in accordance with the expected concentration, add ml of hydrogen peroxide (see 3.2.5) and ml of nitric acid (see 3.2.3) Boil and evaporate to a volume of approximately 50 ml The sample shall not be reduced to dryness In the case of samples with low chromium concentrations this digestion method should be carried out in an autoclave or a microwave oven It is important to follow the manufacturer's instructions Add 10 ml of nitric acid (see 3.2.3) to the evaporated solution Transfer the solution to a 100 ml volumetric flask Add 10 ml of lanthanum chloride solution (see 3.2.6) into the flask, dilute to the mark with water and mix 3.4.3 Water soluble chromium Filter the sample through a membrane filter (see 3.3.3), as soon as possible after collection, and acidify the filtrate immediately with nitric acid (see 3.2.3) to give a pH between and Add 10 ml of lanthanum chloride solution (see 3.2.6) to a 100 ml volumetric flask and make up to the mark with the acidified filtrate, or use another suitable aliquot in accordance with the expected concentration, and mix 3.5 Procedure 3.5.1 Blank test Carry out a blank test in parallel with the determination by the same procedure and using the same quantities of all the reagents as in the sampling and determination, but replacing the test portion by water 3.5.2 Preparation of the calibration solutions Before each set of determinations, prepare from the chromium standard solution (see 3.2.7.2) at least five calibration solutions covering the range of concentrations to be determined; for example: pipette 1,0 ml, 2,5 ml, 5,0 ml, 10,0 ml and 20,0 ml of chromium standard solution (see 3.2.7.2) into a series of 100 ml volumetric flasks Add to each flask depending on the pretreatment (see 3.4.2 and 3.4.3) 10 ml or ml of nitric acid (see 3.2.3) respectively and 10 ml of lanthanum chloride solution (see 3.2.6), dilute to the mark with water and mix These solutions correspond to chromium concentrations of 0,50 mg/l, 1,25 mg/l, 2,50 mg/l, 5,00 mg/l and 10,0 mg/l respectively Proceed accordingly for other concentration ranges of interest 3.5.3 Calibration Set up the instrument in accordance with the manufacturer's instructions (at wavelength l = 357,9 nm) using a nitrous oxide/acetylene flame Aspirate a calibration solution (see 3.5.2) and optimize the aspiration, the burner height and the flame conditions Adjust the response of the instrument to zero absorbance with water In turn, aspirate the set of calibration solutions (see 3.5.2) and the blank solution (see 3.5.1) Plot a graph having the chromium concentrations of the calibration solutions in milligrams per litre as abscissa and the corresponding absorbance values as ordinate Alternatively, data processing facilities can be used to equate the concentration against the absorbance 3.5.4 Test portion measurement Aspirate the prepared test portion (see 3.4.2 or 3.4.3) into the flame and measure the absorbance for chromium After each measurement aspirate water and readjust the zero, if necessary BSI 1997 Page EN 1233 : 1996 3.6 Expression of results 3.7 Interferences The following ions have been tested and shown not to cause interference below the concentration given in table This information was taken from practical tests carried out in a working group in 1984 3.6.1 By reference to the calibration graph obtained (see 3.5.3) or data processing facilities used, determine the concentration of chromium corresponding to the absorbances of the test portion (see 3.5.4) and of the blank solution (see 3.5.1) Calculate the concentration of chromium of the sample using the equation (A ASO)VW r= s VPb where: Table Interfering ions Ion Concentration Ion Concentration mg/l mg/l Sulfate 10 000 Chloride 12 000 Sodium 000 Potassium 000 Magnesium 000 Calcium 000 r is the chromium concentration of the sample, in milligrams per litre; AS is the absorbance of the test portion; ASO is the absorbance of the blank; VP is the volume of the acidified sample in accordance with 3.4.2 or 3.4.3, respectively, in millilitres; b is the sensitivity (slope of the calibration graph) in litres per milligram; VW is the volume of the test portion according to 3.4.2 or 3.4.3 respectively, in millilitres Iron Nickel Copper Cobalt Aluminium Zinc 500 100 100 100 100 100 The total dry residue of the sample shall not exceed 15 g/l and the conductivity should be lower than 2000 mS/m NOTE It is possible to determine the effect of possible interferences by analysing samples spiked with chromium and various concentrations of the potential interfering substance using the method of standard additions 3.6.2 Precision data An interlaboratory test carried out in January 1985 yielded the data given in table The standard solution used was made from deionized water, spiked with chromium The water used was a municipal, biologically treated waste water, spiked with chromium The digestion as described in 3.4.2 was applied; in the atomic absorption spectrometer apparatus, a hollow cathode lamp was used 3.8 Test report The test report shall contain at least the following information: a) a reference to this European Standard; b) a reference to the procedure used; c) complete identification of the sample; d) any other information relevant to the procedure Table Precision data for clause Type of sample l n xS X y sr VCr sR VCR Standard solution 11 43 15,0 14,64 97,5 0,084 0,6 0,798 5,5 Water with added concentration 14 56 2,0 2,06 103,0 0,053 2,6 0,218 10,6 where: l n xS X y sr VCr sR VCR is is is is is is is is is BSI 1997 the the the the the the the the the number of laboratories; number of measured values (without outliers); concentration of samples, in milligrams per litre; overall mean, in milligrams per litre; recovery rate, in percent; repeatability standard deviation, in milligrams per litre; repeatability variation coefficient, in percent; reproducibility standard deviation, in milligrams per litre; reproducibility variation coefficient, in percent Page EN 1233 : 1996 Determination of chromium by electrothermal atomization atomic absorption spectrometry 4.1 Principle Chromium is determined directly in acidified samples by electrothermal atomization atomic absorption spectrometry The sample is introduced into an electrically heated graphite tube and the absorbance is measured at a wavelength of 357,9 nm If necessary, the standard additions technique is employed 4.2 Reagents 4.2.1 See 3.2 4.2.2 Chromium standard solution, with r(Cr) = 0,5 mg/l Add 10,00 ml ± 0,01 ml of the chromium standard solution (see 3.2.7.2) to a 1000 ml volumetric flask Add 10 ml of nitric acid (see 3.2.3) and dilute to the mark with water This solution is stable for at least month 4.3 Apparatus 4.3.1 Atomic absorption spectrometer, equipped with an electrothermal atomizer, chromium hollow cathode lamp and a suitable device for correction of non-specific absorbants 4.3.2 Atomizer tubes The atomizer tubes will vary according to the instrument used but shall be pyrolytically coated and pre-conditioned before use in accordance with the manufacturer's instructions NOTE It is permissible to use a L'vov platform 4.3.3 Automatic sample injector (autosampler) or micro-syringe, of appropriate volume For high precision, an automatic sample injector is necessary 4.4 Sampling and preparation of test portions Follow the procedures described in 3.4 but omit the lanthanum chloride solution Because of the very low levels of chromium being determined, take particular care to avoid any contamination at all stages of sampling and analysis 4.5 Procedure 4.5.1 Blank test Carry out a blank test in parallel with the determination by the same procedure and using the same quantities of all the reagents as in the sampling and determination, but replacing the test portion by water 4.5.2 Preparation of calibration solutions Before each set of determinations, prepare from the chromium standard solution (see 4.2.2) at least five calibration solutions covering the range of concentrations to be determined Prepare the blank solution (see 4.5.1) and use it for zero setting The range of linearity of the calibration graph will depend on the type of instrumentation used, therefore check the range of linearity of the graph before use If the calibration graph departs significantly from linearity, use as the highest calibration standard the one with the highest concentration in the linear portion of the calibration curve, and then adjust accordingly the concentration range of the method For example, to cover the range between mg/l and 25 mg/l of chromium, add 1,0 ml, 2,0 ml, 3,0 ml, 4,0 ml and 5,0 ml of chromium standard solution (see 4.2.2) into a series of 100 ml volumetric flasks, add in accordance with the procedure (see 3.4.2 and 3.4.3) 10 ml or ml respectively of nitric acid (see 3.2.3) to each flask Dilute to the mark with the water and mix These solutions contain 5,0 mg/l, 10,0 mg/l, 15,0 mg/l, 20,0 mg/l and 25,0 mg/l of chromium respectively Prepare these solutions immediately before use 4.5.3 Calibration and determination Set up the instrument in accordance with the manufacturer's instructions 4.5.3.1 Direct measurement Introduce into the atomizer tube (see 4.3.2) a volume of calibration solution (see 4.5.2) sufficient to obtain a satisfactory response on the instrument being used (see note 1), for example 20 ml Optimize the setting of the instrument Using an autosampler or syringe (see 4.3.3) inject the blank solution (see 4.5.1) and calibration solutions (see 4.5.2) Measure the instrument's response by using the peak area (or alternatively the peak height) and construct a calibration graph as described in 3.5.3 Introduce the test portion (see 3.4.2 or 3.4.3) and measure the response by determination of the peak area (or peak height) Carry out each determination in duplicate NOTE An appropriate test portion volume should be in the range ml to 30 ml depending on the instrument used, and the same volume for all test portions, calibration solutions and blanks should be used NOTE A number of matrix modifiers have been suggested for this determination Most manufacturers recommend suitable modifiers for their equipment BSI 1997 Page EN 1233 : 1996 4.5.3.2 Procedure using the method of standard additions When matrix interferences are suspected, this procedure should be used For example, introduce ml of the pretreated test portion (see 3.4.2 or 3.4.3) into each of four 10 ml volumetric flasks To each flask add 0,5 ml of nitric acid (see 3.2.3) Pipette respectively into this series of flasks ml, 0,10 ml, 0,30 ml and 0,60 ml of chromium standard solution (see 4.2.2) Make each flask up to the mark with water and mix Measure the absorbance of each solution following the procedure used in 4.5.3.1 4.6.3 Precision An interlaboratory test carried out in January 1985 yielded the data given in table The standard solution was made from deionized water, spiked with chromium The water tested was drinking water, spiked with chromium In the atomic absorption spectrometer instrument, a hollow cathode lamp was used 4.6 Expression of results 4.8 Test report See 3.8 4.7 Interferences Determine the effect of possible interfering substances by the analysis of samples to which chromium at various concentrations of the potential interfering substances have been added (see 3.7) 4.6.1 If direct measurement is used (see 4.5.3.1), determine the concentration of chromium from the calibration graph corresponding to the peak area (or peak height) of the sample and of the blank as described in 3.6 4.6.2 If the method of standard additions (see 4.5.3.2) is used, construct a graph with the absorbance values plotted on the ordinate and the chromium concentrations plotted on the abscissa Calculate the chromium concentration of the test portions from the value of the negative intercept on the abscissa, taking into account the blank value and any dilution of the sample during pretreatment Alternatively, data processing facilities can be used for this purpose Table Precision data for clause Type of sample l n xS X y sr VCr sR VCR Standard solution Water with added concentration 18 18 71 72 25,0 10,0 23,99 10,94 96,03 109,4 0,689 0,690 2,96 6,2 3,586 4,045 14,9 37,0 where: l n xS X y sr VCr sR VCR is is is is is is is is is BSI 1997 the the the the the the the the the number of laboratories; number of measured values (without outliers); concentration of samples, in micrograms per litre; overall mean, in micrograms per litre; recovery rate, in percent; repeatability standard deviation, in micrograms per litre; repeatability variation coefficient, in percent; reproducibility standard deviation, in micrograms per litre; reproducibility variation coefficient, in percent Page EN 1233 : 1996 Annex A (informative) Information on pretreatment and digestion of sludge and sediment samples A.1 Pretreatment of sludge and sediment samples After sampling, the sludge and sediment samples are stored in the original bottles (see 3.4.1) in a refrigerator, or frozen until further treatment If the determination is to be carried out on a dry residue, the sample is preferably freeze dried, or alternatively dried at 105 ÊC ± ÊC for about 24 h The dried sample is homogenized NOTE Dried sludges and sediments may be hygroscopic, and should therefore be dried again prior to analysis if stored for a very long time A.2 Digestion As an alternative for the digestion described in 3.4.2, the following method can be used Transfer a precisely weighed amount of the samples to the digestion flask (a colourless bottle made of heat-resistant glass or an equivalent glass quality), volume about 100 ml The bottle and the screw cap shall withstand at least a pressure of 200 kPa (120 ÊC) The largest permissible amount of sample is g of dried material, or the equivalent amount of wet sample Add 20 ml of nitric acid (see 3.2.3) Close the digestion flask tightly, and heat to 120 ÊC (200 kPa) for 30 min, following the directions given for the autoclave (alternatively a microwave oven may be used) Cool to room temperature, transfer the solution quantitatively to a 100 ml volumetric flask, and dilute to the mark with water After the undissolved material has settled, the determination is performed on the clear liquid phase BSI 1997 BS EN 1233 : 1997 List of references See national foreword BSI 1997 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI Ð British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: 020 8996 9000 Fax: 020 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: 020 8996 9001 Fax: 020 8996 7001 In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: 020 8996 7111 Fax: 020 8996 7048 Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: 020 8996 7002 Fax: 020 8996 7001 Copyright Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means ± electronic, photocopying, recording or otherwise ± without prior written permission from BSI This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained If permission is granted, the terms may include royalty payments or a licensing agreement Details and advice can be obtained from the Copyright Manager Tel: 020 8996 7070