BS en 12396-2-1999 [PDF]

Zitiervorschau

BRITISH STANDARD

Non-fatty foods Ð Determination of dithiocarbamate and thiuram disulfide residues Ð Part 2: Gas chromatographic method

The European Standard EN 12396-2:1998 has the status of a British Standard

ICS 67.050

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

BS EN 12396-2:1999

BS EN 12396-2:1999

National foreword This British Standard is the English language version of EN 12396-2:1998. The UK participation in its preparation was entrusted to Technical Panel AW/-/3, Food analysis Ð Horizontal methods, which has the responsibility to: Ð aid enquirers to understand the text; Ð present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; Ð monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this panel can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled ªInternational Standards Correspondence Indexº, or by using the ªFindº facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover. This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 1999  BSI 03-1999

ISBN 0 580 30691 7

Amendments issued since publication Amd. No.

Date

Text affected

EN 12396-2

EUROPEAN STANDARD NORME EUROPEÂENNE EUROPAÈISCHE NORM

October 1998

ICS 67.040 Descriptors: food products, chemical analysis, determination of content, pesticides, fungicides, pesticide residues, chromatographic analysis, gas chromatography

English version

Non-fatty foods Ð Determination of dithiocarbamate and thiuram disulfide residues Ð Part 2: Gas chromatographic method

Aliments non gras Ð DeÂtermination des reÂsidus de dithiocarbamates et de bisulfures de thiurame Ð Partie 2: MeÂthode par chromatographie en phase gazeuse

Fettarme Lebensmittel Ð Bestimmung von Dithiocarbamat- und Thiuramdisulfid-RuÈckstaÈnden Ð Teil 2: Gaschromatographisches Verfahren

This European Standard was approved by CEN on 2 October 1998. 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, Czech Republic, 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  1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12396-2:1998 E

Page 2 EN 12396-2:1998

Foreword This European Standard has been prepared by Technical Committee CEN/TC 275, Food analysis Ð Horizontal methods, the Secretariat of which is held by DIN. 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 April 1999, and conflicting national standards shall be withdrawn at the latest by April 1999. This European Standard EN 12396, Non-fatty foods Ð Determination of dithiocarbamate and thiuram disulfide residues, consists of three parts: Part 1: Spectrometric method; Part 2: Gas chromatographic method; Part 3: Xanthogenate method. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

Contents Foreword 1 Scope 2 Normative references 3 Principle 4 Reagents 5 Apparatus 6 Sampling 7 Preparation of the samples 8 Procedure 9 Expression of the results 10 Confirmatory tests 11 Precision 12 Test report Annex A (informative) Precision Annex B (informative) Gas chromatographic operating conditions Annex C (informative) Bibliography

Page 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 7

 BSI 03-1999

Page 3 EN 12396-2:1998

1 Scope

4 Reagents

This European Standard specifies a gas chromatographic method for the determination of residues of dithiocarbamates and thiuram disulfides, which release carbon disulfide under the described conditions (e.g. mancozeb, maneb, propineb, thiuram, zineb). It is applicable to such compounds in and on fruits and some vegetables but also in and on cereals and other foodstuffs of plant origin. Only the quantification of the whole group is possible using this method, not the identification of individual compounds. Generally the maximum residue limits (MRLs) are expressed in terms of carbon disulfide.

4.1 General Unless otherwise stated, use reagents of recognized analytical grade, preferably for pesticide residue analysis, and only distilled or demineralized water. Label all standard containers with name and purity of all pesticides. For the full chemical names and structures, see ISO 1750. Take every precaution to avoid possible contamination of water, solvents, inorganic salts etc. by plastics and rubber materials or even by air. Use only glass containers for storage and handling of all water and reagents.

2 Normative references

4.2 Acetone.

This European Standard incorporates, by dated and 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 12393-1:1998, Non-fatty foods Ð Multiresidue methods for the gas chromatographic determination of pesticide residues Ð Part 1: General considerations. EN 12393-3, Non-fatty foods Ð Mutiresidue methods for the gas chromatographic determination of pesticide residues Ð Part 3: Determination and confirmatory tests. EN 12396-1, Non-fatty foods Ð Determination of dithiocarbamate and thiuram disulfide residues Ð Part 1: Spectrometric method. ISO 1750, Pesticides and other agrochemicals Ð Common names.

4.3 Light petroleum, boiling range 40 8C to 60 8C.

3 Principle The sample is heated with hydrochloric acid and tin(II)chloride in a gas-tight flask to release carbon disulfide from any dithiocarbamates and/or thiuram disulfide present. The quantity of carbon disulfide collecting in the headspace of the flask is determined by gas chromatography (GC) with an electron capture detector (ECD) or with a flame-photometric detector (FPD) in the sulfur mode. For further information on the principle of this method, see [1] to [4].

1)

r is the mass concentration.

 BSI 03-1999

4.4 Carbon disulfide, colourless, at least 99 % of mass concentration. If stored at 220 8C it is stable for 2 years to 3 years. 4.5 Hydrochloric acid, concentrated, r20(HCl) = 1,16 g/ml. 4.6 Tin(II)chloride - hydrochloric acid solution, r(SnCl2´2H2O) = 15 g/l1). Dissolve 15 g of tin(II)chloride dihydrate in 400 ml of concentrated hydrochloric acid (4.5) and dilute to 1 000 ml with water. 4.7 Carbon disulfide stock solution, r(CS2) ≈ 25 mg/ml. Weigh to the nearest 10 mg a stoppered 50 ml volumetric flask with ground glass neck containing 40 ml of acetone (4.2) or light petroleum (4.3). Pipette into this about 1 ml of carbon disulfide (4.4) (according to about 1,25 g), close the flask immediately and weigh again to the nearest 10 mg in order to determine the exact mass of carbon disulfide taken. Dilute to the mark with light petroleum or acetone and mix well. Prepare freshly for each calibration curve. 4.8 Carbon disulfide standard solutions 4.8.1 Carbon disulfide standard solution I, r(CS2) ≈ 10 mg/ml. Pipette 20 ml of carbon disulfide stock solution (4.7) into a 50 ml volumetric flask and dilute to the mark with light petroleum (4.3) or acetone (4.2) as appropriate. Prepare freshly for each calibration curve. 4.8.2 Carbon disulfide standard solution II, r(CS2) ≈ 1 mg/ml. Pipette 5 ml of carbon disulfide standard solution I (4.8.1) into a 50 ml volumetric flask and dilute to the mark with light petroleum (4.3) or acetone (4.2), as appropriate. Prepare freshly for each calibration curve.

Page 4 EN 12396-2:1998

5 Apparatus 5.1 General Thoroughly clean glassware shall be used. See EN 12393-1:1998, 5.1 for the cleaning of glassware. Usual laboratory equipment and, in particular, the following. 5.2 Digestion flask, 250 ml glass bottle with a screw cap which has been drilled with a 3 mm hole and fitted with a polytetrafluoroethylene (PTFE) septum. 5.3 Water bath, capable of being controlled at approximately 70 8C. 5.4 Gas-tight injection syringes, 100 ml and 1 000 ml. Check the gas-tightness of the syringes regularly. 5.5 Gas chromatograph, equipped with an electron capture detector (ECD) or a flame-photometric detector (FPD) in the sulfur mode (filter 394 nm). A suitable GC system, preferably equipped with separate heaters for injector, detector and column oven, should be used. See annex B. Variation in the detector sensitivity should be checked periodically by verifying the calibration curve using carbon disulfide standard solutions. For the determination of carbon disulfide, packed glass columns are mostly used. For stationary phases and support materials see EN 12393-3.

6 Sampling Prepare the laboratory sample according to a generally recommended method of sampling to achieve a representative part of the product to be analysed. NOTE Sampling procedures for the official control of pesticide residues in and on fruits and vegetables are given in EEC directive 79/700/EEC [5].

7 Preparation of the samples 7.1 Test sample If the sample reaches the laboratory frozen, store it at 220 8C before analysis. Where possible, carry out the analysis of fresh samples immediately after their arrival in the laboratory. Do not analyse a laboratory sample which is wholly or extensively spoiled. For analysis take only the portion of the laboratory sample to which the maximum residue limit applies. No further plant-parts may be removed. A record of the plant-parts which have been removed shall be kept. The sample thus prepared is the analytical sample. If the sample cannot be analysed immediately, store it at 0 8C to 5 8C for no longer than 2 days before analysis. The reduction of the analytical sample shall be carried out in such a way that representative portions are obtained (e.g. by division into four and selection of opposite quadrants). When the samples are in small units (e.g. small fruits, vegetables, cereals), the analytical sample shall be thoroughly mixed before weighing out

the test portion. When the samples are in larger units, take wedge-shaped sections (e.g. large fruits and vegetables) or cross-sections (e.g. cucumbers) which include the outer surface from each unit. NOTE The residues of dithiocarbamate and thiuram disulfide, which are on the surface of the plant-parts and are not systemic, decompose rapidly, especially in chopped samples. Therefore precautions should be taken to avoid decomposition.

If samples have to be stored for more than 2 days, they shall be deep-frozen at 220 8C. To ensure that even after thawing representative samples can be taken, prepare portions of the product which are each sufficient for one analysis. 7.2 Test portion Weigh out test portions of masses up to 200 g to an accuracy of ± 1 %. After weighing out the test portion, remove any parts which would interfere with the analytical procedure. In the case of stone fruits, the stones are removed after weighing out. The basis for the calculation of the residue mass fraction is the mass of the original test portion (with stones). The test portion shall not be cut or reduced to smaller pieces than can just pass the neck of the reaction flask, as the residues of dithiocarbamate and thiuram disulfide fungicides fall the more the test portion is cut. Analyse the test portion immediately after cutting.

8 Procedure 8.1 Safety aspects WARNING: Many dithiocarbamates, thiuram disulfides and carbon disulfide are toxic by various routes of exposure, especially in concentrated form. When working with dithiocarbamates, thiuram disulfides and carbon disulfide, consult safety data sheets of the manufacturer for information. Vapours from some volatile solvents are toxic. Several of these solvents can easily be absorbed through skin. Use effective fume hoods to remove vapours of these solvents as they are set free. 8.2 Preparation of blanks Prepare reagent and commodity blanks. Spiked recovery tests at levels appropriate to the maximum residue limits should be carried out as specified in annex A and shall lead to satisfactory results. Test the purity of the reagents and solvents by performing reagent blanks. Test solvents by gas chromatography to determine whether they are free from any interfering impurity whose concentration is at the limit of determination. Ensure that the laboratory is free from atmospheric contamination that would give a background response for carbon disulfide, by injecting a few hundred microlitres of air into the GC column. The chromatograph shall not show any interfering impurity. NOTE 1 Analysts should thoroughly familiarize themselves with the method before starting the analyses. NOTE 2 Some vegetables (e.g. those of the family Cruciferae) contain naturally occurring compounds which release carbon disulfide under the conditions described in this European Standard. Therefore the analysis of such vegetables can lead to false positive results.

 BSI 03-1999

Page 5 EN 12396-2:1998

8.3 Gas chromatographic operating conditions Pure (oxygen-free) and dry (water-free) nitrogen [this is especially important when using an electron capture detector (ECD)], or an argon/methane mixture (in case of a pulsed ECD) shall be used as the carrier gas for packed columns. The flow rate depends on the size and the type of the column used. Molecular sieve filters shall be installed for all gas supplies and regenerated regularly. Make sure that the GC conditions (column length, stationary phase type, injector, detector and column temperatures, gas flow rates, etc.) are such that the separation of the carbon disulfide likely to be present from interfering peaks originating from the samples is as complete as possible.

9 Expression of the results

NOTE Capillary GC has become an important technique with a separation power superior to that of packed columns. This capillary technique is recommended especially in the case of complex substrates.

If the results indicate that the amount of residue approaches or exceeds the maximum residue limit, at least two further test portions shall be examined.

Typical GC operating conditions are presented in annex B.

NOTE The routine limit of determination depends on the amount of test portion used. If the mass of the test portion is 50 g, the routine limit of determination lies at approximately 0,01 mg/kg.

8.4 Preparation of the calibration curve Place 50 ml of water into each of four digestion flasks and add 100 ml of tin(II)chloride - hydrochloric acid solution (4.6). Fit the screw caps containing the PTFE septa. Inject through the different septa, into the water, aliquot portions of carbon disulfide standard solutions (4.8) to provide a suitable range of concentrations (e.g. 1 ml, 5 ml, 10 ml, 20 ml, 40 ml, 60 ml, 80 ml and 100 ml of 1 mg/ml solution (4.8.2) corresponding to 0,02 mg/kg; 0,1 mg/kg; 0,2 mg/kg; 0,4 mg/kg; 0,8 mg/kg; 1,2 mg/kg; 1,6 mg/kg and 2,0 mg/kg of residue as carbon disulfide in a 50 g sample). Place the spiked digestion flasks in the water bath (5.3) for 2 h and follow the procedure described in 8.5.2. Plot a calibration curve from the peak areas or peak heights against amounts of carbon disulfide added. NOTE As the response from the flame photometric detector follows a square function, the chart recorder readings should be plotted logarithmically to give linearity.

8.5 Sample measurement 8.5.1 Preparation of the digestion flask Introduce a 50 g test portion into the digestion flask (5.2), add 100 ml of tin(II)chloride - hydrochloric acid solution (4.6) and immediately close the flask tightly with the PTFE septum and screw cap. Place the flask into the thermostatically controlled water bath (5.3) for 2 h. Shake vigorously the flask for 2 min at least 3 times during the digestion stage, in order to fully release carbon disulfide from any dithiocarbamate and thiuram disulfide present. Remove the flask and allow to cool to room temperature. 8.5.2 Gas chromatographic measurement Inject 25 ml to 300 ml of the cooled headspace gas from the digestion flask at room temperature into the gas chromatograph (5.5). Injections of the sample shall be preceded and followed by injection of the headspace gas above one of the standard solutions obtained in 8.4.  BSI 03-1999

Read off the amount of carbon disulfide present in the sample from the calibration curve. Calculate the mass fraction of residue, w, in milligrams per kilogram, expressed in terms of carbon disulfide using equation (1): m w= c (1) mt where: mc mt

is the mass of carbon disulfide released (read off from the calibration curve), in micrograms; is the mass of the test portion (before the removal of any parts, for example stones), in grams.

10 Confirmatory tests Analyses for confirmation using a different method should be performed, especially in those cases in which the result indicates that the maximum residue limit has been exceeded. NOTE 1 The method in EN 12396-1 permits carbon disulfide to be determined spectrometrically. NOTE 2 The method in EN 12396-3 permits carbon disulfide to be determined spectrometrically as xanthogenate and is especially useful for the determination of low levels of dithiocarbamate and thiuram disulfide residues. NOTE 3 Coupled gas chromatography-mass spectrometry (GC-MS) is a specific method to confirm the identity and the quantity of carbon disulfide in samples prepared according to 8.5.1. NOTE 4 A method which determines undestroyed ethylene and propylene bis-dithiocarbamates as their respective sodium salts by means of gel chromatographic separation and on-line photometric determination at a wavelength of 285 nm is described in [6].

11 Precision Some general criteria, based on experience, are given in annex A as guidance for the analyst.

12 Test report The test report shall contain at least the following information: Ð all information necessary for the identification of the sample; Ð a reference to this European Standard; Ð the results and the units in which they have been expressed; Ð date and type of sampling procedure (if known); Ð date of receipt of sample in the laboratory; Ð date of test; Ð any particular points observed in the course of the test; Ð any operations not specified in the method or regarded as optional which might have affected the results.

Page 6 EN 12396-2:1998

Annex A (informative) Precision A.1 General The precision of the analytical method should be evaluated in accordance with the requirements of ISO 5725:1986 [7]. A.2 Repeatability conditions Repeatability conditions are defined as conditions under which mutually independent test results are obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within short intervals of time. Each laboratory should periodically determine if its results under repeatability conditions are acceptable by analysing samples which have been spiked with appropriate pesticides, or preferably by using samples with incurred residues at concentrations, if possible, near to the maximum residue limits. Table A.1 shows examples of acceptable differences of test results obtained under repeatability conditions. Table A.1 Ð Examples of acceptable differences of test results obtained under repeatability conditions Residue level

Difference (± )

mg/kg

mg/kg

0,010

0,005

0,100

0,025

1,000

0,125

Residue level

Difference (± )

mg/kg

mg/kg

0,10

0,05

1,00

0,25

B.1 The following gas chromatographic operating conditions have been proven to be satisfactory. B.2 Packed columns Column size Column filling

1,20 m 3 2 mm Tenax, 190 mm to 250 mm (60 mesh to 80 mesh) Column temperature 100 8C 1,50 m 3 4 mm Porapak Q, 150 mm to 190 mm (80 mesh to 100 mesh) Column temperature 200 8C

Table A.2 Ð Examples of acceptable differences of test results obtained under reproducibility conditions

0,01

Annex B (informative) Gas chromatographic operating conditions

Column size Column filling

In this example, 0,01 mg/kg is near the limit of determination. Determine intermediate values by interpolation from a log-log graph. A.3 Reproducibility conditions Reproducibility conditions are defined as those conditions under which test results are obtained with this method on identical test material in different laboratories with different operators using different equipment. Table A.2 shows acceptable differences of test results obtained under reproducibility conditions.

0,01

A.4 Recovery The laboratory performance should be assessed periodically by carrying out recovery studies to establish the recovery level of pesticide residues. This should be done by analysing samples which have been spiked with ethanolic solutions of nabam or thiuram, at concentrations near to the maximum residue limit and at 1/10th of it. These samples should be of the same type as those examined for residue content. The mean of recoveries from replicate determinations should fall within the range of 70 % up to 110 %, with a relative standard deviation less or equal to 30 %.

Column size Column filling

1,80 m 3 4 mm 2 % OV 1 on Gas Chrom Q, 150 mm to 190 mm (80 mesh to 100 mesh) Column temperature 100 8C Column size Column filling

1,80 m 3 2 mm 3 % OV 1 on Chromosorb AW-DMCS, 150 mm to 190 mm (80 mesh to 100 mesh) Column temperature 75 8C Detector

Electron capture detector, temperature 300 8C Injector temperature About 150 8C

In this example, 0,01 mg/kg is near the limit of determination. Determine intermediate values by interpolation from a log-log graph.  BSI 03-1999

Page 7 EN 12396-2:1998

B.3 Capillary columns Column

Fused silica capillary CP-Sil 8CB (50 m 3 0,32 mm; film thickness 1,2 mm)

Column temperature: Ð isothermal 55 8C for 10 min; Ð programmed to rise at 15 8C/min from 55 8C to 200 8C; Ð isothermal at 200 8C for 10 min. Detector

Electron capture detector, temperature 300 8C

Injector temperature About 150 8C

 BSI 03-1999

Annex C (informative) Bibliography [1] McLEOD, H.A., and McCULLY, C.A. Head space gas chromatographic procedure for screening food samples for dithiocarbamate pesticide residues, J. Assoc. Off. Anal. Chem., 1969, 52, 1226-1230. [2] MINISTRY OF AGRICULTURE FISHERIES AND FOOD [UK], Committee for Analytical Methods for Residues of Pesticides and Veterinary Products in Foodstuffs, Panel on determination of dithiocarbamate residues. Determination of residues of dithiocarbamate pesticides in foodstuffs by a headspace method, Analyst, 1981, 106, 782-787. [3] EEC document: 1729/VI/80 - final 1 [4] Part II, Method Dithiocarbamates In: P.A. GREVE, ed. Analytical methods for residues of pesticides in foodstuffs, 5th edition, SDU, Den Hague, 1988. [5] EEC Commission directive of 24.7.79 (79/700/EEC). Establishing community methods of sampling for the official control of pesticide residues in and on fruits and vegetables, Official Journal of the European Communities L 207, 15.8.79. [6] PFLUGMACHER, J and EBING, W. Method S 21, Ethylene and propylene bisdithiocarbamate fungicides, Manual of Pesticide Residue Analysis, VCH Verlagsgesellschaft Weinheim 1987, 1, 407-412. [7] ISO 5725:1986, Precision of test methods Ð Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests.

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.