1、BSI BS*IS0*103L2 95 1624669 0498847 327 = BRITISH STANDARD - Implementation of IS0 10312 : 1995 Ambient air - Determination of asbestos fibres - Direct-transfer transmission electron microscopy method BS IS0 10312 : 1995 BSI BS*ISO*LO3L2 95 Lb24669 0498848 2b3 Amd. No. BS IS0 10312 : 1996 Date Text
2、affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee Em, Air quaiity, upon which the following bodies were represented AEA Technology Association of Consulting Scientists British Cement Association British Coal Corpor
3、ation Chartered Institution of Environmental Health Combustion Engineering Association Department of Health Department of the Environment (Her Majestys Inspectorate of Pollution) Department of A-ade and Industry (Laboratory of the Government Chemist) Engineering Equipment and Materials Users Associa
4、tion European Resin Manufacturers Association GAMBICA (BEAMA Ltd.) Health and Safety Executive Institute of Petroleum , National Society for Clean Air Royal Society of Chemistry The foilowjng bodies were also represented in the drafting of the standard, through subcommittees and panelc: Asbestosis R
5、esearch Council BCIRA British Iron and Steel Producers Association Dement of A-ade and Industry (National Physical Laboratory) Fibre Cement Manufadurers Association Limited Lead Development Association Meteorological Office WRA Technology Ltd. This British Standard, having been prepared under the di
6、recon of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15 October 1995 O BSI 1995 Amendments issued since publication The following BSI references relate to the work on this standard Committee reference EHE! Draft for comme
7、nt 92/50316 DC ISBN O 580 24833 X BSI BS*ISO*L312 75 Lb24669 O498847 LTT BS IS0 10312 : 1995 National foreword This British Standard reproduces verbatim IS0 10312 : 1995 and implements it as the UK national standard. This British Standard is published under the direction of the Health and Environmen
8、t Sector Board whose Technical Committee Em, Air quaJity, has the responsibility to: - aid enquire= to understand the text; - present to the responsible international committee any enquiries on interpretation, or proposais for change, and keep UK interests informed; - monitor related international a
9、nd European developments and promulgate them intheUK. NOTE. International and European Standards, as well as overseas standards, are available from Customer Senices, BSI, 389 Chiswick High Road, London W4 4AL. Compliance with a British Standard does not of itself confer immunity from legai obligatio
10、ns. i BSI BS*IS0*10322 95 W Lb24669 0498850 LL W I N T E R NAT I O NA L STANDARD IS0 10312 First edition 1995-05-01 Ambient air - Determination of asbestos fibres - Direct-transfer transmission electron microscopy method Air ambiant - Dtermination des fibres damiante - Mthode de microscopie lectroni
11、que transmission directe Reference number IS0 1031 2:1995(E) IS0 10312:1995(E) Contents Page 1 Scope 1 2 Normative references . 2 3 Definitions . 2 4 Principle . 3 5 Symbols of units and abbreviations 4 6 Reagents . 5 7 Apparatus 5 8 Air sample collection . 10 9 Procedure for analysis . 11 10 Perfor
12、mance characteristics 18 11 Test report . 19 Annexes A B C D E F G H J Determination of operating conditions for plasma asher 22 Calibration procedures . 23 Structure counting criteria 25 Fibre identification procedure 33 Determination of the concentrations of asbestos fibres and bundles longer than
13、 5 pm, and PCM equivalent asbestos fibres . 42 Calculation of results 43 Strategies for collection of air samples . 47 Methods for removal of gypsum fibres . 48 Bibliography 49 Q IS0 1995 All rights reserved . Unless otherwise specified. no part of this publication may be reproduced or utilized in a
14、ny form or by any means. electronic or mechanical. including photocopying and microfilm. without permission in writing from the publisher . International Organization for Standardization Case Postale 56 CH-1211 Genve 20 Switzerland Printed in Switzerland II BSI BS*ISO*LO3L2 95 = Lb24669 0498852 794
15、IS0 10312:1995(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a sub
16、ject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnical Commission (I
17、EC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Sta
18、ndard IS0 1031 2 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 3, Ambient atmospheres. Annexes A, B, C, D, E and F form an integral part of this International Standard. Annexes G, H and J are for information only. . 111 BSI BS*IS0*10332 95 1624664 0498853 620 IS0 10312
19、:1995(E) Introduction This International Standard is applicable to the determination of airborne asbestos in a wide range of ambient air situations, including the interior atmospheres of buildings, and for detailed evaluation of any atmosphere in which asbestos structures are likely to be present. B
20、ecause the best available medical evidence indicates that the numerical fibre concentration and the fibre sizes are the relevant parameters for evaluation of the inhalation hazards, a fibre counting technique is the only logical approach. Most fibres in ambient atmospheres are not asbestos, and ther
21、efore there is a requirement for fibres to be identified. Many airborne asbestos fibres in ambient atmospheres have diameters below the resolution limit of the optical microscope. This International Standard is based on transmission electron microscopy, which has adequate resolution to allow detecti
22、on of small fibres and is currently the only technique capable of unequivocal identification of the majority of individual fibres of asbestos. Asbestos is often found, not as single fibres, but as very complex, aggregated struc- tures which may or may not be also aggregated with other particles. The
23、 fibres found suspended in an ambient atmosphere can often be identified unequivocally, if a sufficient measurement effort is expended. However, if each fibre were to be identified in this way, the analysis would become prohibitively expensive. Because of instrumental deficiencies or because of the
24、nature of the particulate, some fibres cannot be positively identified as asbestos, even though the measurements all indicate that they could be asbestos. Subjective factors therefore contribute to this measurement, and consequently a very precise definition of the procedure for identifica- tion and
25、 enumeration of asbestos fibres is required. The method specified in this International Standard is designed to provide the best description possible of the nature, numerical concentration, and sizes of asbestos- containing particles found in an air sample. This International Standard is necessarily
26、 complex, because the instrumental techniques used are com- plex, and also because a very detailed and logical procedure must be specified to reduce the subjective aspects of the measurement. The method of data recording specified in this International Standard is de- signed to allow re-evaluation o
27、f the structure counting data as new med- ical evidence becomes available. All of the feasible specimen preparation techniques result in some modification of the airborne particulate. Even the collection of particles from a three-dimensional airborne dispersion onto a two-dimensional filter surface
28、can be considered a modification of the particulate, and some of the particles in most samples are modified by the specimen preparation procedures. However, the procedures spec- ified in this International Standard are designed to minimize the disturb- ance of the collected particulate material, and
29、 the effect of those disturbances which do occur can be evaluated. This International Standard describes the method of analysis for a single air filter. However, one of the largest potential errors in characterizing asbestos in ambient atmospheres is associated with the variability be- tween filter
30、samples. For this reason, it is necessary to design a replicate sampling scheme in order to determine this International Standards ac- curacy and precision. iv INTERNATIONAL STANDARD IS0 10312:1995(E) Ambient air - Determination of asbestos fibres - Direct-transfer transmission electron microscopy m
31、ethod 1 Scope 1.1 Substance determined This International Standard specifies a reference method using transmission electron microscopy for the determination of the concentration of asbestos structures in ambient atmospheres and includes measurement of the lengths, widths and aspect ratios of the asb
32、estos structures. The method allows deter- mination of the type(s) of asbestos fibres present. The method cannot discriminate between individual fibres of the asbestos and non-asbestos analogues of the same amphibole mineral. 1.2 Type of sample The method is defined for polycarbonate capillary-pore
33、filters or cellulose ester (either mixed esters of cellu- lose or cellulose nitrate) filters through which a known volume of air has been drawn. The method is suitable for determination of asbestos in both exterior and building atmospheres. 1.3 Measuring range The range of concentration which can be
34、 determined is 50 structures/mm2 to 7 O00 structures/mm2 on the filter. The air concentrations represented by these values are a function of the volume of air sampled. There is no lower limit to the dimensions of asbestos fibres which can be detected. In practice, microscopists vary in their ability
35、 to detect very small asbestos fibres. Therefore, a minimum length of 0,5 pm has been defined as the shortest fibre to be incorporated in the reported results. 1.4 Limit of detection The limit of detection theoretically can be lowered in- definitely by filtration of progressively larger volumes of a
36、ir and by extending the examination of the speci- mens in the electron microscope. In practice, the lowest achievable limit of detection for a particular area of TEM specimen examined is controlled by the total suspended particulate concentration. For total suspended articulate concentrations of ap-
37、 proximately 10 pg/m , corresponding to clean, rural atmospheres, and assuming filtration of 4 O00 litres of air, an analytical sensitivity of 0,5 structurel1 can be obtained, equivalent to a limit of detection of 1,8 structure/l, if an area of 0,195 mm2 of the TEM specimens is examined. If higher t
38、otal suspended particulate concentrations are present, the volume of air filtered must be reduced in order to maintain an acceptable particulate loading on the filter, leading to a proportionate increase in the analytical sensitivity. c: Where this is the case, lower limits of detection can be achie
39、ved by increasing the area of the TEM speci- mens that is examined. In order to achieve lower limits of detection for fibres and bundles longer than 5 pm, and for PCM equivalent fibres, lower magni- fications are specified which permit more rapid ex- amination of larger areas of the TEM specimens wh
40、en the examination is limited to these dimensions of fi- bre. The direct analytical method cannot be used if the general particulate loading of the sample collection filter exceeds approximately 10 pg/cm2 of filter sur- face, which corresponds to approximately 1 O % cov- erage of the collection filt
41、er by particulate. If the total suspended particulate is largely organic material, the limit of detection can be lowered significantly by using an indirect preparation method. 1 BSI BS*ISO*10312 95 m 1624669 0498855 4T3 m IS0 1031 2: 1995( E) 2 Normative references The following standards contain pr
42、ovisions which, through reference in this text, constitute provisions of this International Standard. At the time of publica- tion, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate t
43、he possibility of applying the most re- cent editions of the standards indicated below. Members of IEC and IS0 maintain registers of cur- rently valid International Standards. IS0 4225: 1994, Air quality - General aspects - Vo- cabulary. IS0 4226:1993, Air quality - General aspects - Units of measur
44、ement. IS0 Standard Handbook No. 2:1993, Quantities and units. IS0 Standard Handbook No. 3: 1989, Statistical Meth- ods. 3 Definitions For the purposes of this International Standard, the following definitions apply (see also IS0 4225). 3.1 acicular: The shape of an extremely slender crystal with cr
45、oss-sectional dimensions which are small relative to its length, .e. needle-like. 3.2 amphibole: A group of rock-forming ferromagnesium silicate minerals, closely related in crystal form and composition, with the nominal for- mula: A, or ,B2C,T8022(OH,F,CI)2 where A = K, Na B = Fe2+, Mn, Mg, Ca, Na
46、C = AI, Cr, Ti, Fe3+, Mg, Fe2+ T = Si, AI, Cr, Fe3+, Ti In some varieties of amphibole, these elements can be partially substituted by Li, Pb or Zn. Amphibole is characterized by a cross-linked double chain of Si-O tetrahedra with a si1icon:oxygen ratio of 4:11, by co- lumnar or fibrous prismatic cr
47、ystals and by good prismatic cleavage in two directions parallel to the crystal faces and intersecting at angles of about 56“ and 124“. 3.3 amphibole asbestos: Amphibole in an asbestiform habit. 3.4 analytical sensitivity: The calculated airborne asbestos structure concentration in asbestos structur
48、es/litre, equivalent to counting of one asbestos structure in the analysis. The method in this International Standard does not specify an analytical sensitivity. 3.5 asbestiform: A specific type of mineral fibrosity in which the fibres and fibrils possess high tensile strength and flexibility. 3.6 a
49、sbestos: A term applied to a group of silicate minerals belonging to the serpentine and amphibole groups which have crystallized in the asbestiform habit, causing them to be easily separated into long, thin, strong fibres when crushed or processed. The Chemical Abstracts Service Registry Numbers of the most common asbestos varieties are: chrysotile (1 2001-29-51, crocidolite (1 2001-28-41, grnerite asbestos amosite) (1 21 72-73-5), anthophyllite asbestos (77536-67-51, tremolite asbestos (77536-68-6) and actinolite asbestos (77536-66-4). 3.7 asbestos structure: A term app
