SIST ISO 22262-1:2013
Air quality - Bulk materials - Part 1: Sampling and qualitative determination of asbestos in commercial bulk materials
Air quality - Bulk materials - Part 1: Sampling and qualitative determination of asbestos in commercial bulk materials
This part of ISO 22262 specifies methods for sampling bulk materials and identification of asbestos in commercial
bulk materials. This part of ISO 22262 specifies appropriate sample preparation procedures and describes in
detail the procedure for identification of asbestos by polarized light microscopy and dispersion staining.
This part of ISO 22262 also specifies simple procedures for separation of asbestos fibres from matrix materials
such as asphalt, cement, and plastics products. Optionally, identification of asbestos can be carried out using
scanning electron microscopy or transmission electron microscopy with energy dispersive X-ray analysis.
Information is also provided on common analytical problems, interferences and other types of fibre that may
be encountered in the analysis.
This part of ISO 22262 is applicable to qualitative identification of asbestos in specific types of manufactured
asbestos-containing products and commercial minerals. This part of ISO 22262 is applicable to the analysis
of fireproofing, thermal insulation, and other manufactured products or minerals in which asbestos fibres can
readily be separated from matrix materials for identification.
NOTE This part of ISO 22262 is intended for use by microscopists who are familiar with polarized light microscopy
methods and the other analytical procedures specified (References [16]?[19]). It is not the intention of this part of ISO 22262
to provide instruction in the fundamental analytical techniques.
Qualité de l'air - Matériaux solides - Partie 1: Échantillonnage et dosage qualitatif de l'amiante dans les matériaux solides d'origine commerciale
La présente partie de l'ISO 22262 spécifie les méthodes d'échantillonnage de matériaux solides et d'identification
de l'amiante dans les matériaux solides d'origine commerciale. La présente partie de l'ISO 22262 spécifie
les procédures appropriées de préparation de l'échantillon et décrit en détail la procédure d'identification de
l'amiante par microscopie en lumière polarisée et dispersion de coloration.
La présente partie de l'ISO 22262 spécifie également des procédures simples de séparation des fibres
d'amiante des matériaux matriciels tels que les produits bitumineux, à base de ciment et de plastique.
L'identification de l'amiante peut également être effectuée en utilisant la microscopie électronique à balayage
ou la microscopie électronique à transmission avec analyse en dispersion d'énergie des rayons X. Des
informations sont également données sur les problèmes habituels d'analyse, les interférences et autres types
de fibres susceptibles d'être rencontrés au cours de l'analyse.
La présente partie de l'ISO 22262 est applicable à l'identification qualitative de l'amiante dans des types
spécifiques de produits manufacturés et de minéraux commercialisés contenant de l'amiante. La présente
partie de l'ISO 22262 est applicable à l'analyse des matériaux ignifuges, produits d'isolation thermique et
autres produits manufacturés ou minéraux dans lesquels les fibres d'amiante peuvent être facilement séparées
des matériaux matriciels pour être identifiées.
NOTE La présente partie de l'ISO 22262 est destinée à être utilisée par les microscopistes familiarisés avec les
méthodes de microscopie en lumière polarisée et par les personnes chargées de l'analyse, expérimentées et familiarisées
avec les procédures d'analyse spécifiées (Références [16] à [19]). L'objectif de la présente partie de l'ISO 22262 n'est pas
de fournir des informations sur les techniques d'analyse fondamentale.
Kakovost zraka - Razsuti materiali - 1. del: Vzorčenje in kvantitativno določevanje azbesta v razsutih materialih za prodajo
Ta del standarda ISO 22262 določa metode za vzorčenje razsutih materialov in določevanje azbesta v razsutih materialih za prodajo. Ta del standarda ISO 22262 določa ustrezne postopke za pripravo vzorcev in podrobno opisuje postopek za določevanje azbesta s polarizirano svetlobno mikroskopijo in disperzijskim obarvanjem. Ta del standarda ISO 22262 določa tudi preproste postopke za ločevanje azbestnih vlaken od matričnih materialov, kot so asfalt, cement in plastični izdelki. Po izbiri se lahko določevanje azbesta izvede tudi z uporabo vrstične elektronske mikroskopije ali presevne mikroskopije z energijsko-disperzivno rentgensko analizo. Zagotovljene so tudi informacije v zvezi s splošnimi analiznimi težavami, motnjami in drugimi vrstami vlaken, do katerih lahko pride med analizo. Ta del standarda ISO 22262 se uporablja za kvalitativno določevanje azbesta v posebnih vrstah proizvedenih izdelkov in mineralov za prodajo, ki vsebujejo azbest. Ta del standarda ISO 22262 se uporablja za analizo izdelkov ali mineralov za odpornost na ogenj in toplotno izolacijo ter drugih proizvedenih izdelkov ali mineralov, v katerih je mogoče azbestna vlakna preprosto ločiti od matričnih materialov za določevanje.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2013
.DNRYRVW]UDND5D]VXWLPDWHULDOLGHO 9]RUþHQMHLQNYDQWLWDWLYQRGRORþHYDQMH
D]EHVWDYUD]VXWLKPDWHULDOLK]DSURGDMR
Air quality - Bulk materials - Part 1: Sampling and qualitative determination of asbestos in
commercial bulk materials
Qualité de l'air - Matériaux solides - Partie 1: Échantillonnage et dosage qualitatif de
l'amiante dans les matériaux solides d'origine commerciale
Ta slovenski standard je istoveten z: ISO 22262-1:2012
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL ISO
STANDARD 22262-1
First edition
2012-07-01
Air quality — Bulk materials —
Part 1:
Sampling and qualitative determination of
asbestos in commercial bulk materials
Qualité de l’air — Matériaux solides —
Partie 1: Échantillonnage et dosage qualitatif de l’amiante dans les
matériaux solides d’origine commerciale
Reference number
©
ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
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Published in Switzerland
ii © ISO 2012 – All rights reserved
Contents Page
Foreword . v
Introduction .vi
1 Scope . 1
2 Terms and definitions . 1
3 Symbols and abbreviated terms . 7
4 Principle . 8
4.1 General . 8
4.2 Substance determination . 8
4.3 Type of sample . 8
4.4 Range . 8
4.5 Limit of detection . 9
4.6 Limitations of PLM in the detection of asbestos . 9
5 Sample collection . 9
5.1 Requirements . 9
5.2 Procedure .10
6 Sample preparation .14
6.1 General .14
6.2 Removal of organic materials by ashing .14
6.3 Removal of soluble constituents by acid treatment .14
6.4 Sedimentation and flotation .14
6.5 Combination of gravimetric reduction procedures .14
7 Analysis by PLM .14
7.1 Requirements .14
7.2 Qualitative analysis by PLM .19
8 Analysis by SEM .29
8.1 General .29
8.2 Requirements .29
8.3 Calibration .29
8.4 Sample preparation .30
8.5 Qualitative analysis by SEM .30
9 Analysis by transmission electron microscope .31
9.1 General .31
9.2 Requirements .32
9.3 Calibration .32
9.4 Sample preparation .33
9.5 Qualitative analysis by TEM .33
10 Test report .35
Annex A (normative) Types of commercial asbestos-containing material .36
Annex B (normative) Interference colour chart .40
Annex C (normative) Dispersion staining charts .41
Annex D (normative) Asbestos identification by PLM and dispersion staining in
commercial materials .43
Annex E (normative) Asbestos identification by SEM in commercial materials .52
Annex F (normative) Asbestos identification by TEM in commercial materials .58
Annex G (informative) Example of sampling record .67
Annex H (informative) Example of test report .68
Bibliography .69
iv © ISO 2012 – All rights reserved
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject 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. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22262-1 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 3, Ambient
atmospheres.
ISO 22262 consists of the following parts, under the general title Air quality — Bulk materials:
— Part 1: Sampling and qualitative determination of asbestos in commercial bulk materials
The following part is under preparation:
— Part 2: Quantitative determination of asbestos by gravimetric and microscopical methods
Introduction
In the past, asbestos was used in a wide range of products. Three varieties of asbestos found extensive
commercial application. Chrysotile accounted for approximately 95 % of consumption, and this variety is
therefore likely to be encountered most frequently during the analysis of samples. Materials containing high
proportions of chrysotile asbestos were used in buildings and in industry for fireproofing, thermal insulation,
and acoustic insulation. Chrysotile was also used to reinforce materials to improve fracture and bending
characteristics. A large proportion of the chrysotile produced was used in asbestos–cement products. These
include flat sheets, tiles and corrugated sheets for roofing, pipes and open troughs for the collection of rainwater,
as well as pressure pipes for supply of potable water. Chrysotile was also incorporated into products such as
decorative coatings and plasters, glues, sealants and resins, floor tiles, gaskets, and road paving. In some
products, chrysotile was incorporated to modify rheological properties, e.g. in the manufacture of ceiling tile
panels and oil drilling muds. Long textile grade chrysotile fibre was also used to manufacture woven, spun,
felted and paper products.
Amosite and crocidolite accounted for almost all of the remaining asbestos use. Amosite was widely used as
fireproofing and in thermal insulation products, e.g. pipe coverings and insulating boards. Crocidolite was also
used as fireproofing and in thermal insulation products, but was particularly prized because it is highly resistant
to acids, flexible enough to be spun and has high tensile strength for reinforcement. Crocidolite found application
as a reinforcing fibre in acid containers such as those used for lead–acid batteries, in high-performance textiles
and gaskets, and was particularly important for the manufacture of high-pressure asbestos cement pipes for
delivery of potable water.
Three other types of asbestos are currently regulated. Materials containing commercial anthophyllite are
relatively rare, but they have also been used as a filler and reinforcing fibre in composite materials, and as
a filtration medium. Tremolite asbestos and actinolite asbestos were not extensively used commercially, but
some occurrences of tremolite asbestos in surfacing materials and fireproofing have been found in Japan.
Tremolite asbestos and actinolite asbestos sometimes occur as contaminants of other commercial minerals.
Other minerals can also occur as asbestos. For example, richterite asbestos and winchite asbestos occur
at mass fractions between 0,1 % and 6 % associated with vermiculite, formerly mined at Libby, Montana,
USA. Vermiculite from this source was widely distributed and is often found as loose fill insulation and as a
constituent in a range of construction materials and fireproofing.
While the asbestos mass fraction in some products can be very high and in some cases approach 100 %, in
other products the mass fractions of asbestos used were significantly lower and often between 1 % and 15 %.
In some ceiling tile panels, the mass fraction of asbestos used was close to 1 %. There are only a few known
materials in which the asbestos mass fraction used was less than 1 %. Some adhesives, sealing compounds
and fillers were manufactured in which asbestos mass fractions were lower than 1 %. There are no known
materials in which asbestos was intentionally added at mass fractions lower than 0,1 %.
In this part of ISO 22262, procedures for collection of samples and qualitative analysis of commercial bulk
materials for the presence of asbestos are specified. The primary method used to identify asbestos is polarized
light microscopy. Because of the wide range of matrix materials into which asbestos was incorporated, polarized
light microscopy cannot provide reliable analysis of all types of asbestos-containing materials in untreated
samples. The applicability of polarized light microscopy can be extended by the use of simple treatments such
as ashing and treatment with acid. Optionally, either scanning electron microscopy or transmission electron
microscopy may be used as an alternative or confirmatory method to identify asbestos.
Although this part of ISO 22262 specifies that, optionally, a visual estimate of the asbestos mass fraction within
very broad ranges may also be made, it is recognized that the accuracy and reproducibility of such estimates
is very limited. Quantitative determination of the asbestos content can be needed for a number of reasons,
e.g. assessment and management of the risk from asbestos materials in buildings or to comply with regulatory
definitions for asbestos-containing materials. The necessity to quantify asbestos in a material depends on the
maximum mass fraction that has been adopted by the jurisdiction to define an asbestos-containing material
for the purpose of regulation. Definitions range from “any asbestos” to 0,1 %, 0,5 % or 1 %. For jurisdictions in
which an asbestos-containing material is defined as one containing “any asbestos”, a particular problem is how
to determine whether a material does not contain asbestos, since all methods have limits of detection.
vi © ISO 2012 – All rights reserved
For practical purposes, since no known commercial materials exist in which commercial asbestos was
intentionally added at mass fractions lower than 0,1 %, this part of ISO 22262 specifies that samples be
classified as asbestos-containing (i.e. containing more than 0,1 % asbestos) if either chrysotile, amosite,
crocidolite or anthophyllite, or any of these varieties in combination, is detected in the analysis. When the
definition of an asbestos-containing material is either 0,5 % or 1 %, depending on the nature of the product, it
is often necessary to proceed to other parts of this International Standard in order to quantify the asbestos for
the purpose of defining the regulatory status of the material.
The occurrence of tremolite, actinolite or richterite/winchite in a material is usually a consequence of natural
contamination of the constituents, and the detection of these minerals does not necessarily indicate that
the mass fraction is more than 0,1 % asbestos. Accordingly, determination of the regulatory status of these
materials by any of the criteria can often be achieved only by quantitative analysis. Since these minerals were
not specifically mined and utilized for their fibrous properties, they may also occur in materials as either non-
asbestiform or asbestiform analogues, or as mixtures of both. Evaluation of these types of material may require
a more detailed analysis.
Simple analytical procedures such as polarized light microscopy are not capable of detecting or reliably
identifying asbestos in some types of commercial products containing asbestos, either because the fibres are
below the resolution of optical microscopy or because the matrix material adheres too strongly to the fibres.
For these types of product, it may be necessary to utilize electron microscopy.
For a list of parts of this International Standard, see the Foreword.
[11] [13]
The method specified in this part of ISO 22262 is based on MDHS 77, VDI 3866 Part 1, VDI 3866 Part
[14] [15] [8] [10] [12]
4, , VDI 3866 Part 5, , AS 4964-2004, EPA/600/R-93/116, and NF X46-020:2008.
INTERNATIONAL STANDARD ISO 22262-1:2012(E)
Air quality — Bulk materials — Part 1: Sampling and qualitative
determination of asbestos in commercial bulk materials
IMPORTANT — The electronic file of this document contains colours which are considered to be
useful for the correct understanding of the document. Users should therefore consider printing this
document using a colour printer.
1 Scope
This part of ISO 22262 specifies methods for sampling bulk materials and identification of asbestos in commercial
bulk materials. This part of ISO 22262 specifies appropriate sample preparation procedures and describes in
detail the procedure for identification of asbestos by polarized light microscopy and dispersion staining.
This part of ISO 22262 also specifies simple procedures for separation of asbestos fibres from matrix materials
such as asphalt, cement, and plastics products. Optionally, identification of asbestos can be carried out using
scanning electron microscopy or transmission electron microscopy with energy dispersive X-ray analysis.
Information is also provided on common analytical problems, interferences and other types of fibre that may
be encountered in the analysis.
This part of ISO 22262 is applicable to qualitative identification of asbestos in specific types of manufactured
asbestos-containing products and commercial minerals. This part of ISO 22262 is applicable to the analysis
of fireproofing, thermal insulation, and other manufactured products or minerals in which asbestos fibres can
readily be separated from matrix materials for identification.
NOTE This part of ISO 22262 is intended for use by microscopists who are familiar with polarized light microscopy
methods and the other analytical procedures specified (References [16]–[19]). It is not the intention of this part of ISO 22262
to provide instruction in the fundamental analytical techniques.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
achromat
microscope objective in which chromatic aberration is corrected for two wavelengths and spherical aberration
and other aperture-dependent defects are minimized for one other wavelength (usually about 550 nm)
EXAMPLE One wavelength less than about 500 nm, the other greater than about 600 nm.
NOTE This term does not imply any degree of correction for curvature of image field; coma and astigmatism are
minimized for wavelengths within the achromatic range.
[3]
[ISO 10934-1:2002, 2.6]
2.2
acicular
shape shown by an extremely slender crystal with cross-sectional dimensions which are small relative to its
length, i.e. needle-like
[4]
[ISO 13794:1999, 2.1]
2.3
alpha refractive index
α
lowest refractive index exhibited by a fibre
2.4
amphibole
group of rock-forming ferromagnesium silicate minerals, closely related in crystal form and composition, and
having the nominal formula:
A B C T O (OH,F,Cl)
0-1 2 5 8 22 2
where
A is K, Na
2+
B is Fe , Mn, Mg, Ca, Na
3+ 2+
C is Al, Cr, Ti, Fe , Mg, Fe
3+
T is Si, Al, Cr, Fe , Ti
NOTE 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 silicon:oxygen ratio of 4:11, by columnar or fibrous
prismatic crystals and by good prismatic cleavage in two directions parallel to the crystal faces and intersecting at angles
of about 56° and 124°.
[4]
[ISO 13794:1999, 2.2]
2.5
amphibole asbestos
amphibole in an asbestiform habit
[4]
[ISO 13794:1999, 2.3]
2.6
analyser
polar used after the object to determine optical effects produced by the object on the light, polarized or
otherwise, with which it is illuminated
NOTE It is usually positioned between the objective and the primary image plane.
[3]
[ISO 10934-1:2002, 2.117.1]
2.7
anisotropy
state or quality of having different properties along different axes
EXAMPLE An anisotropic transparent particle can show different refractive indices with the vibration direction of
incident light.
2.8
asbestiform
specific type of mineral fibrosity in which the fibres and fibrils possess high tensile strength and flexibility
[4]
[ISO 13794:1999, 2.6]
2.9
asbestos
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, flexible, strong fibres
when crushed or processed
NOTE 1 The Chemical Abstracts Service Registry Numbers of the most common asbestos varieties are: chrysotile
(12001-29-5), crocidolite (12001-28-4), grunerite asbestos (amosite) (12172-73-5), anthophyllite asbestos (77536-67-5),
tremolite asbestos (77536-68-6) and actinolite asbestos (77536-66-4).
2 © ISO 2012 – All rights reserved
[4]
[ISO 13794:1999, 2.7]
NOTE 2 Other varieties of asbestiform amphibole, such as richterite asbestos and winchite asbestos (Reference [20]),
are also found in some products such as vermiculite and talc.
2.10
aspect ratio
ratio of length to width of a particle
[4]
[ISO 13794:1999, 2.10]
2.11
Bertrand lens
intermediate lens which transfers an image of the back focal plane of the objective into the primary image plane
NOTE The Bertrand lens is used for conoscopic observation in polarized light microscopy and for adjustment of the
microscope illuminating system, especially in phase-contrast and modulation-contrast microscopy.
[3]
[ISO 10934-1:2002, 2.87.2]
2.12
birefringence
quantitative expression of the maximum difference in refractive index due to double refraction
[3]
[ISO 10934-1:2002, 2.16]
2.13
camera length
equivalent projection length between the specimen and its electron diffraction pattern, in the absence of lens action
[4]
[ISO 13794:1999, 2.12]
2.14
chrysotile
fibrous mineral of the serpentine group which has the nominal composition:
Mg Si O (OH)
3 2 5 4
NOTE Most natural chrysotile deviates little from this nominal composition. In some varieties of chrysotile, minor
3+ 3+ 2+ 3+ 2+ 2+ 2+
substitution of silicon by Al may occur. Minor substitution of magnesium by Al , Fe , Fe , Ni , Mn and Co may
also be present. Chrysotile is the most prevalent type of asbestos.
[4]
[ISO 13794:1999, 2.13]
2.15
cleavage
breaking of a mineral along one of its crystallographic directions
[4]
[ISO 13794:1999, 2.14]
2.16
cleavage fragment
fragment of a crystal that is bounded by cleavage faces
NOTE Crushing of non-asbestiform amphibole generally yields elongated fragments that conform to the definition of
a fibre, but rarely have aspect ratios exceeding 30:1.
2.17
crossed polars
state in which the polarization directions of the polars (polarizer and analyser) are mutually perpendicular
[3]
[ISO 10934-1:2002, 2.117.2]
2.18
d-spacing
distance between identical adjacent and parallel planes of atoms in a crystal
[4]
[ISO 13794:1999, 2.18]
2.19
dispersion
variation of refractive index with wavelength of light
[1]
[ISO 7348:1992, 05.03.26]
2.20
dispersion staining
effect produced when a transparent object is immersed in a surrounding medium, the refractive index of which
is equal to that of the object at a wavelength in the visible range, but which has a significantly higher optical
dispersion than the object
NOTE Only the light refracted at the edges of the object is imaged, and this gives rise to colours at the interface
between the object and the surrounding medium. The particular colour is a measure of the wavelength at which the
refractive index of the object and that of the medium are equal.
2.21
electron diffraction
technique in electron microscopy by which the crystal structure of a specimen is examined
[4]
[ISO 13794:1999, 2.19]
2.22
electron scattering power
extent to which a thin layer of substance scatters impinging electrons from their original directions
[4]
[ISO 13794:1999, 2.20]
2.23
energy dispersive X-ray analysis
EDXA
measurement of the energies and intensities of X-rays by use of a solid-state detector and multichannel
analyser system
[4]
[ISO 13794:1999, 2.22]
2.24
eucentric
condition in which the area of interest of an object is placed on a tilting axis, at the intersection of the electron
beam with that axis, and is in the plane of focus
[4]
[ISO 13794:1999, 2.23]
2.25
extinction
condition in which an optically anisotropic object appears dark when observed between crossed polars
[3]
[ISO 10934-1:2002, 2.51]
NOTE Extinction occurs when the vibration directions of the crystal are parallel to the vibration directions in the
polarizer and analyser.
2.26
extinction angle
angle between the extinction position and the position at which the length of a fibre is parallel to the polarizer
or analyser vibration directions
4 © ISO 2012 – All rights reserved
2.27
fibril
single fibre of asbestos which cannot be further separated longitudinally into smaller components without
losing its fibrous properties or appearances
[4]
[ISO 13794:1999, 2.25]
2.28
fibre
elongated particle which has parallel or stepped sides
[4]
[ISO 13794:1999, 2.26]
NOTE For the purposes of this part of ISO 22262, a fibre is defined to have an aspect ratio greater than or equal to 3:1.
2.29
fibre bundle
structure composed of parallel, smaller diameter fibres attached along their lengths
NOTE A fibre bundle may exhibit diverging fibres at one or both ends.
[4]
[ISO 13794:1999, 2.27]
2.30
gamma refractive index
γ
highest refractive index exhibited by a fibre
2.31
habit
characteristic crystal growth form, or combination of these forms, of a mineral, including characteristic
irregularities
[4]
[ISO 13794:1999, 2.30]
2.32
high-efficiency particulate air filter
HEPA
filter that is at least 99,97 % efficient by volume on 0,3 µm particles
[6]
[ISO 14952-1:2003, 2.13]
2.33
isotropic
having the same properties in all directions
[5]
[ISO 14686:2003, 2.23]
2.34
Köhler illumination
method of illuminating specimens in which an image of the illumination source is projected by a collector into
the plane of the aperture diaphragm in the front focal plane of the condenser, which then projects an image of
an illuminated field diaphragm at the opening of the collector into the specimen plane
2.35
lamda zero
λ
matching wavelength corresponding to the dispersion staining colour shown by a particle in an immersion medium
NOTE At this wavelength, the particle and the immersion medium have the same refractive index.
2.36
matrix
material in a laboratory sample within which fibres are dispersed
2.37
Miller index
set of either three or four integer numbers used to specify the orientation of a crystallographic plane in relation
to the crystal axes
[4]
[ISO 13794:1999, 2.33]
2.38
pleochroism
property of an optically anisotropic medium by which it exhibits different brightness and/or colour for different
directions of light propagation, or for different vibrations, on account of variation in selective spectral absorption
of transmitted light
2.39
polarized light
light in which the vibrations are partially or completely suppressed in certain directions at any given instant
NOTE The vector of vibration may describe a linear, circular or elliptical shape.
[3]
[ISO 10934-1:2002, 2.88.1]
2.40
polarizer
polar placed in the light path before the object
[3]
[ISO 10934-1:2002, 2.117.4]
2.41
polar
device which selects plane-polarized light from natural light
[3]
[ISO 10934-1:2002, 2.117]
2.42
refractive index
n
ratio of the speed of light (more exactly, the phase velocity) in a vacuum to that in a given medium
[3]
[ISO 10934-1:2002, 2.124]
2.43
retardation
difference in optical path length expressed in wavelengths, length units or phase angles between two mutually
perpendicular plane-polarized waves
[3]
[ISO 10934-1:2002, 2.128]
2.44
selected area electron diffraction
technique in electron microscopy in which the crystal structure of a small area of a sample is examined
[4]
[ISO 13794:1999, 2.38]
6 © ISO 2012 – All rights reserved
2.45
serpentine
group of common rock-forming minerals having the nominal formula:
Mg Si O (OH)
3 2 5 4
[4]
[ISO 13794:1999, 2.39]
2.46
sign of elongation
description of the directions of the high and low refractive indices in a fibre
NOTE The fibre is described as positive when the higher refractive index is parallel to the length of the fibre, and
negative when the lower refractive index is parallel to the length of the fibre.
2.47
temperature coefficient of refractive index
measure of the change of refractive index of a substance with temperature
2.48
twinning
occurrence of crystals of the same species joined together at a particular mutual orientation, and such that the
relative orientations are related by a definite law
[4]
[ISO 13794:1999, 2.41]
2.49
unopened fibre
large diameter asbestos fibre bundle that has not been separated into its constituent fibrils or fibres
[4]
[ISO 13794:1999, 2.42]
2.50
zone-axis
line or crystallographic direction through the centre of a crystal which is parallel to the intersection edges of the
crystal faces defining the crystal zone
[4]
[ISO 13794:1999, 2.43]
3 Symbols and abbreviated terms
dn
change of RI of an immersion medium per degree Celsius change of temperature
dT
n RI of a liquid for the sodium D line (589,3 nm) and at a temperature of 25 °C
D
α lowest RI of an anisotropic particle
β intermediate RI of an anisotropic particle
γ highest RI of an anisotropic particle
λ wavelength at which the RI of a particle is equal to the RI of the liquid in which it is immersed
ED electron diffraction
EDXA energy dispersive X-ray analysis
FWHM full width, half maximum
HEPA high-efficiency particle absolute
MEC mixed esters of cellulose
PC polycarbonate
PCOM phase contrast optical microscopy
PLM polarized light microscopy
RI refractive index
SAED selected area electron diffraction
SEM scanning electron microscopy
TEM transmission electron microscopy
4 Principle
4.1 General
A suitable tool is used, in compliance with the relevant safety regulations, to take a sample from the material to
be analysed. The sample is then appropriately packed and labelled for transportation to the laboratory.
A representative sample of the bulk material is initially examined using a stereo-binocular microscope.
Typical fibres are removed using tweezers and mounted in appropriate liquid immersion media on slides
for examination by polarized light microscopy. Asbestos fibres are identified based on morphology, colour,
pleochroism, and the α (lowest) and γ (highest) refractive indices qualitatively assessed using the dispersion
staining technique. Detection of commercial asbestos (chrysotile, amosite, crocidolite or anthophyllite), either
alone or in combination, is assumed to indicate that the asbestos is present at a mass fraction exceeding 0,1 %.
Optionally, a visual estimate of the asbestos mass fraction is reported in one of several broad mass fraction
ranges. Tremolite, actinolite and richterite/winchite are identified by the same procedure, but since they are
usually present as contaminants of mineral products, detection of these minerals does not provide information
as to their minimum mass fraction. Optionally, fibres may be identified by SEM or TEM.
4.2 Substance determination
This International Standard specifies a number of reference methods for determination of asbestos in
solid materials. This part of ISO 22262 provides a method for qualitative analysis of specific commercial
products for the presence of asbestos (chrysotile, amosite, crocidolite, tremolite, actinolite, anthophyllite and
richterite/winchite). Other parts of this International Standard provide methods for the analysis of specific types
of commercial products for which the use of PLM on the untreated sample yields unacceptable rates of error,
and for the quantification of asbestos in the low mass fraction range below approximately 5 %.
4.3 Type of sample
The method specified in this part of ISO 22262 is applicable to sampling and analysis of commercial products
from which individual fibres of asbestos can be manually separated from the matrix material, either by picking
fibres from surfaces and newly fractured surfaces, or after chemical treatments, acid extraction or ashing,
such that the fibres can be identified by one of the specified identification methods. This part of ISO 22262
is generally applicable to asbestos-containing building materials such as fireproofing, thermal pipe and boiler
insulations, asbestos cement, plasters, roofing, and other similar materials. The method is also applicable to
the identification of asbestos in a range of other industrial minerals and materials.
4.4 Range
Experience from proficiency testing has shown that the range of this part of ISO 22262, when it is applied to a
suitably prepared sample in which the asbestos fibres are sufficiently large to be optically visible using a low-
8 © ISO 2012 – All rights reserved
magnification stereomicroscope, is from less than 0,1 % to 100 %. The lower end of the range can be extended
downwards by use of appropriate techniques.
4.5 Limit of detection
The limit of detection of this method is defined as the detection and identification of one fibre or fibre bundle in
the amount of sample examined. The limit of detection that can be achieved depends on:
a) the nature of the matrix of the sample;
b) the size of the asbestos fibres and bundles;
c) the use of appropriate sample preparation and matrix reduction procedures;
d) the amount of time expended on examination of the sample;
e) the method of analysis used — PLM, SEM or TEM.
With appropriate matrix reduction procedures that are tailored to the nature of the sample, the limit of detection
can be significantly lower than 0,01 %.
4.6 Limitations of PLM in the detection of asbestos
The ability to detect and identify asbestos by PLM is limited by the resolution of the optical microscope and
sometimes by the masking effects of other materials that comprise the balance of the sample. Asbestos fibres
with widths below approximately 0,2 µm are unlikely to be detected by PLM. However, for all varieties of
amphibole asbestos, and most varieties of chrysotile, a large proportion of the mass comprises fibres that
exceed this width and, because of this, asbestos can be reliably detected by PLM. Accordingly, provided that
the nature of the matrix material on the microscope preparation is such that it does not obscure any asbestos
fibres that might be present, a non-detected result by PLM indicates that the mass fraction of asbestos is below
the limit of detection.
One commercial source of chrysotile presents problems of detection by PLM. Chrysotile originating from the
Coalinga deposit in California, USA, contains no fibrils longer than approximately 30 µm and, if these are well
dispersed in a sample matrix, the majority of the chrysotile is below the size that can be reliably detected and
identified by PLM. The range of application of Coalinga chrysotile is limited to floor tiles, ceiling tiles, drywall
joint compounds, mastics, paints, sealants, adhesives, drilling mud, moulded cement building products, and
as filler in some plastics. There is a high probability that this variety of chrysotile may not be detected by PLM,
even when present in high mass fractions. The size distribution of Coalinga chrysotile makes it unsuitable for
most other applications in which asbestos was used and the possibility that it will be encountered in other types
of product can generally be discounted. If, on the basis of PLM examination, Coalinga chrysotile is suspected
to be present, it is recommended that the sample be examined by electron microscopy.
Asbestos fibres may not be detected by PLM because they are obscured by the matrix of the sample. The
matrix reduction methods specified in this part of ISO 22262 are intended to minimize the possibility of failing
to detect asbestos in such samples.
5 Sample collection
5.1 Requirements
5.1.1 Sampling apparatus. Depending on the nature of the material to be sampled, an appropriate tool is
required for collection of the sample. If the material is soft, such as thermal insulation or fireproofing, a knife or
scalpel may be sufficient. In other situations, a cork borer may be used to sample all of the layers of a layered
material. If the material is hard, e.g. asbestos–cement, tools such as pliers, a wire cutter, hammer and chisel or
rotating hole saw can be needed.
5.1.2 HEPA vacuum cleaner. A HEPA vacuum cleaner, approved for asbestos, is required for cleaning
around the sampling location after collection of the sample to minimize dispersion of asbestos-containing dust
or particulate matter.
5.1.3 Materials and supplies for sampling.
5.1.3.1 Wetting agent. A wetting agent may be used to limit the generation of airborne dust during the
collection of the sample. Water, or water to which a small amount of surfactant has been added, may be applied
to the surface before sampling using a spray bottle or brush.
IMPORTANT If a sample is being collected for the purpose of product identification, use no wetting
agent, since this may result in alteration of the sample composition by addition of surfactant, and by
dissolution and loss of water-soluble constituents.
5.1.3.2 Filler. After collection of the sample, a minor repair may be necessary to seal the damaged area.
Depending on the circumstances, spray paint, touch-up paint or plaster may be used.
5.1.3.3 Sample containers. Appropriate dust-tight containers are required for packaging the sample. Plastic
bags with “zip” closures or bottles with screw caps may be used.
5.1.3.4 Labels. A method for labelling samples is required. Self-adhesive paper labels may be used.
Alternatively, a waterproof marker may be sufficient for field use.
5.1.3.5 Dust mask. A dust mask with filter approved for respiratory protection against airborne asbestos
fibres. Approved filters conform to either the National Institute for Occupational Safety and Health (NIOSH)
[9]
P100 or the European Standard EN 143 P3 specification. Other types of personal protective equipment may
be used if warranted by the situation.
5.1.3.6 Light. Either a flashlight or an appropriate light source is required for collection of samples in dark locations.
5.1.3.7 Plastic bags. Labelled plastic bags of appropriate size that can be closed tightly and are required
to collect the waste generated during sampling. Bags containing waste should be placed inside another tightly
closed plastic bag.
5.1.3.8 Cleaning supplies. Cleaning materials, such as disposable paper towels and a supply of water, are
required for cleaning sampling tools to avoid cross-contamination between samples.
5.1.3.9 Location identifiers. The use of some means of identifying the precise location from which each
sample is taken is recommended, since it may be necessary to resample the material at a later date to resolve
discrepancies if they arise. A location identifier is invaluable if the sample collected is found not to be representative
of the overall area, such as if the sample has been taken from a patch in a location that has been repaired. A
specific colour of spray paint, or appropriate permanent labels applied to the precise location, may be used.
5.2 Procedure
5.2.1 Safety precautions
Handling asbestos is regulated by many jurisdictions, and regulations often specify a variety of procedures to
ensure that individuals performing work and those in close proximity are not exposed to excessive concentrations
of airborne asbestos. Exceptions from the regulations are generally permitted for some types of activity that are
minimally invasive, such as the removal of material samples for analysis.
IMPORTANT — Care is necessary during sampling of materials that may contain asbestos, and precautions
should be taken to avoid creating and inhaling airborne asbestos particles when sampling materials
suspected of containing asbestos. If the handling instructions in this clause are followed, it may be
10 © ISO 2012 – All rights reserved
assumed that the level of dust meets the thresholds of safety defined in the regulations. In exceptional
cases, more extensive precautions may be necessary to prevent the release of airborne fibres.
Sometimes different materials may have been applied to a surface as several layers. It is recommended that
samples of all of the individual layers be collected. If a borer or hole-sawing device is used to penetrat
...
INTERNATIONAL ISO
STANDARD 22262-1
First edition
2012-07-01
Air quality — Bulk materials —
Part 1:
Sampling and qualitative determination of
asbestos in commercial bulk materials
Qualité de l’air — Matériaux solides —
Partie 1: Échantillonnage et dosage qualitatif de l’amiante dans les
matériaux solides d’origine commerciale
Reference number
©
ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
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Tel. + 41 22 749 01 11
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Published in Switzerland
ii © ISO 2012 – All rights reserved
Contents Page
Foreword . v
Introduction .vi
1 Scope . 1
2 Terms and definitions . 1
3 Symbols and abbreviated terms . 7
4 Principle . 8
4.1 General . 8
4.2 Substance determination . 8
4.3 Type of sample . 8
4.4 Range . 8
4.5 Limit of detection . 9
4.6 Limitations of PLM in the detection of asbestos . 9
5 Sample collection . 9
5.1 Requirements . 9
5.2 Procedure .10
6 Sample preparation .14
6.1 General .14
6.2 Removal of organic materials by ashing .14
6.3 Removal of soluble constituents by acid treatment .14
6.4 Sedimentation and flotation .14
6.5 Combination of gravimetric reduction procedures .14
7 Analysis by PLM .14
7.1 Requirements .14
7.2 Qualitative analysis by PLM .19
8 Analysis by SEM .29
8.1 General .29
8.2 Requirements .29
8.3 Calibration .29
8.4 Sample preparation .30
8.5 Qualitative analysis by SEM .30
9 Analysis by transmission electron microscope .31
9.1 General .31
9.2 Requirements .32
9.3 Calibration .32
9.4 Sample preparation .33
9.5 Qualitative analysis by TEM .33
10 Test report .35
Annex A (normative) Types of commercial asbestos-containing material .36
Annex B (normative) Interference colour chart .40
Annex C (normative) Dispersion staining charts .41
Annex D (normative) Asbestos identification by PLM and dispersion staining in
commercial materials .43
Annex E (normative) Asbestos identification by SEM in commercial materials .52
Annex F (normative) Asbestos identification by TEM in commercial materials .58
Annex G (informative) Example of sampling record .67
Annex H (informative) Example of test report .68
Bibliography .69
iv © ISO 2012 – All rights reserved
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject 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. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22262-1 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 3, Ambient
atmospheres.
ISO 22262 consists of the following parts, under the general title Air quality — Bulk materials:
— Part 1: Sampling and qualitative determination of asbestos in commercial bulk materials
The following part is under preparation:
— Part 2: Quantitative determination of asbestos by gravimetric and microscopical methods
Introduction
In the past, asbestos was used in a wide range of products. Three varieties of asbestos found extensive
commercial application. Chrysotile accounted for approximately 95 % of consumption, and this variety is
therefore likely to be encountered most frequently during the analysis of samples. Materials containing high
proportions of chrysotile asbestos were used in buildings and in industry for fireproofing, thermal insulation,
and acoustic insulation. Chrysotile was also used to reinforce materials to improve fracture and bending
characteristics. A large proportion of the chrysotile produced was used in asbestos–cement products. These
include flat sheets, tiles and corrugated sheets for roofing, pipes and open troughs for the collection of rainwater,
as well as pressure pipes for supply of potable water. Chrysotile was also incorporated into products such as
decorative coatings and plasters, glues, sealants and resins, floor tiles, gaskets, and road paving. In some
products, chrysotile was incorporated to modify rheological properties, e.g. in the manufacture of ceiling tile
panels and oil drilling muds. Long textile grade chrysotile fibre was also used to manufacture woven, spun,
felted and paper products.
Amosite and crocidolite accounted for almost all of the remaining asbestos use. Amosite was widely used as
fireproofing and in thermal insulation products, e.g. pipe coverings and insulating boards. Crocidolite was also
used as fireproofing and in thermal insulation products, but was particularly prized because it is highly resistant
to acids, flexible enough to be spun and has high tensile strength for reinforcement. Crocidolite found application
as a reinforcing fibre in acid containers such as those used for lead–acid batteries, in high-performance textiles
and gaskets, and was particularly important for the manufacture of high-pressure asbestos cement pipes for
delivery of potable water.
Three other types of asbestos are currently regulated. Materials containing commercial anthophyllite are
relatively rare, but they have also been used as a filler and reinforcing fibre in composite materials, and as
a filtration medium. Tremolite asbestos and actinolite asbestos were not extensively used commercially, but
some occurrences of tremolite asbestos in surfacing materials and fireproofing have been found in Japan.
Tremolite asbestos and actinolite asbestos sometimes occur as contaminants of other commercial minerals.
Other minerals can also occur as asbestos. For example, richterite asbestos and winchite asbestos occur
at mass fractions between 0,1 % and 6 % associated with vermiculite, formerly mined at Libby, Montana,
USA. Vermiculite from this source was widely distributed and is often found as loose fill insulation and as a
constituent in a range of construction materials and fireproofing.
While the asbestos mass fraction in some products can be very high and in some cases approach 100 %, in
other products the mass fractions of asbestos used were significantly lower and often between 1 % and 15 %.
In some ceiling tile panels, the mass fraction of asbestos used was close to 1 %. There are only a few known
materials in which the asbestos mass fraction used was less than 1 %. Some adhesives, sealing compounds
and fillers were manufactured in which asbestos mass fractions were lower than 1 %. There are no known
materials in which asbestos was intentionally added at mass fractions lower than 0,1 %.
In this part of ISO 22262, procedures for collection of samples and qualitative analysis of commercial bulk
materials for the presence of asbestos are specified. The primary method used to identify asbestos is polarized
light microscopy. Because of the wide range of matrix materials into which asbestos was incorporated, polarized
light microscopy cannot provide reliable analysis of all types of asbestos-containing materials in untreated
samples. The applicability of polarized light microscopy can be extended by the use of simple treatments such
as ashing and treatment with acid. Optionally, either scanning electron microscopy or transmission electron
microscopy may be used as an alternative or confirmatory method to identify asbestos.
Although this part of ISO 22262 specifies that, optionally, a visual estimate of the asbestos mass fraction within
very broad ranges may also be made, it is recognized that the accuracy and reproducibility of such estimates
is very limited. Quantitative determination of the asbestos content can be needed for a number of reasons,
e.g. assessment and management of the risk from asbestos materials in buildings or to comply with regulatory
definitions for asbestos-containing materials. The necessity to quantify asbestos in a material depends on the
maximum mass fraction that has been adopted by the jurisdiction to define an asbestos-containing material
for the purpose of regulation. Definitions range from “any asbestos” to 0,1 %, 0,5 % or 1 %. For jurisdictions in
which an asbestos-containing material is defined as one containing “any asbestos”, a particular problem is how
to determine whether a material does not contain asbestos, since all methods have limits of detection.
vi © ISO 2012 – All rights reserved
For practical purposes, since no known commercial materials exist in which commercial asbestos was
intentionally added at mass fractions lower than 0,1 %, this part of ISO 22262 specifies that samples be
classified as asbestos-containing (i.e. containing more than 0,1 % asbestos) if either chrysotile, amosite,
crocidolite or anthophyllite, or any of these varieties in combination, is detected in the analysis. When the
definition of an asbestos-containing material is either 0,5 % or 1 %, depending on the nature of the product, it
is often necessary to proceed to other parts of this International Standard in order to quantify the asbestos for
the purpose of defining the regulatory status of the material.
The occurrence of tremolite, actinolite or richterite/winchite in a material is usually a consequence of natural
contamination of the constituents, and the detection of these minerals does not necessarily indicate that
the mass fraction is more than 0,1 % asbestos. Accordingly, determination of the regulatory status of these
materials by any of the criteria can often be achieved only by quantitative analysis. Since these minerals were
not specifically mined and utilized for their fibrous properties, they may also occur in materials as either non-
asbestiform or asbestiform analogues, or as mixtures of both. Evaluation of these types of material may require
a more detailed analysis.
Simple analytical procedures such as polarized light microscopy are not capable of detecting or reliably
identifying asbestos in some types of commercial products containing asbestos, either because the fibres are
below the resolution of optical microscopy or because the matrix material adheres too strongly to the fibres.
For these types of product, it may be necessary to utilize electron microscopy.
For a list of parts of this International Standard, see the Foreword.
[11] [13]
The method specified in this part of ISO 22262 is based on MDHS 77, VDI 3866 Part 1, VDI 3866 Part
[14] [15] [8] [10] [12]
4, , VDI 3866 Part 5, , AS 4964-2004, EPA/600/R-93/116, and NF X46-020:2008.
INTERNATIONAL STANDARD ISO 22262-1:2012(E)
Air quality — Bulk materials — Part 1: Sampling and qualitative
determination of asbestos in commercial bulk materials
IMPORTANT — The electronic file of this document contains colours which are considered to be
useful for the correct understanding of the document. Users should therefore consider printing this
document using a colour printer.
1 Scope
This part of ISO 22262 specifies methods for sampling bulk materials and identification of asbestos in commercial
bulk materials. This part of ISO 22262 specifies appropriate sample preparation procedures and describes in
detail the procedure for identification of asbestos by polarized light microscopy and dispersion staining.
This part of ISO 22262 also specifies simple procedures for separation of asbestos fibres from matrix materials
such as asphalt, cement, and plastics products. Optionally, identification of asbestos can be carried out using
scanning electron microscopy or transmission electron microscopy with energy dispersive X-ray analysis.
Information is also provided on common analytical problems, interferences and other types of fibre that may
be encountered in the analysis.
This part of ISO 22262 is applicable to qualitative identification of asbestos in specific types of manufactured
asbestos-containing products and commercial minerals. This part of ISO 22262 is applicable to the analysis
of fireproofing, thermal insulation, and other manufactured products or minerals in which asbestos fibres can
readily be separated from matrix materials for identification.
NOTE This part of ISO 22262 is intended for use by microscopists who are familiar with polarized light microscopy
methods and the other analytical procedures specified (References [16]–[19]). It is not the intention of this part of ISO 22262
to provide instruction in the fundamental analytical techniques.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
achromat
microscope objective in which chromatic aberration is corrected for two wavelengths and spherical aberration
and other aperture-dependent defects are minimized for one other wavelength (usually about 550 nm)
EXAMPLE One wavelength less than about 500 nm, the other greater than about 600 nm.
NOTE This term does not imply any degree of correction for curvature of image field; coma and astigmatism are
minimized for wavelengths within the achromatic range.
[3]
[ISO 10934-1:2002, 2.6]
2.2
acicular
shape shown by an extremely slender crystal with cross-sectional dimensions which are small relative to its
length, i.e. needle-like
[4]
[ISO 13794:1999, 2.1]
2.3
alpha refractive index
α
lowest refractive index exhibited by a fibre
2.4
amphibole
group of rock-forming ferromagnesium silicate minerals, closely related in crystal form and composition, and
having the nominal formula:
A B C T O (OH,F,Cl)
0-1 2 5 8 22 2
where
A is K, Na
2+
B is Fe , Mn, Mg, Ca, Na
3+ 2+
C is Al, Cr, Ti, Fe , Mg, Fe
3+
T is Si, Al, Cr, Fe , Ti
NOTE 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 silicon:oxygen ratio of 4:11, by columnar or fibrous
prismatic crystals and by good prismatic cleavage in two directions parallel to the crystal faces and intersecting at angles
of about 56° and 124°.
[4]
[ISO 13794:1999, 2.2]
2.5
amphibole asbestos
amphibole in an asbestiform habit
[4]
[ISO 13794:1999, 2.3]
2.6
analyser
polar used after the object to determine optical effects produced by the object on the light, polarized or
otherwise, with which it is illuminated
NOTE It is usually positioned between the objective and the primary image plane.
[3]
[ISO 10934-1:2002, 2.117.1]
2.7
anisotropy
state or quality of having different properties along different axes
EXAMPLE An anisotropic transparent particle can show different refractive indices with the vibration direction of
incident light.
2.8
asbestiform
specific type of mineral fibrosity in which the fibres and fibrils possess high tensile strength and flexibility
[4]
[ISO 13794:1999, 2.6]
2.9
asbestos
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, flexible, strong fibres
when crushed or processed
NOTE 1 The Chemical Abstracts Service Registry Numbers of the most common asbestos varieties are: chrysotile
(12001-29-5), crocidolite (12001-28-4), grunerite asbestos (amosite) (12172-73-5), anthophyllite asbestos (77536-67-5),
tremolite asbestos (77536-68-6) and actinolite asbestos (77536-66-4).
2 © ISO 2012 – All rights reserved
[4]
[ISO 13794:1999, 2.7]
NOTE 2 Other varieties of asbestiform amphibole, such as richterite asbestos and winchite asbestos (Reference [20]),
are also found in some products such as vermiculite and talc.
2.10
aspect ratio
ratio of length to width of a particle
[4]
[ISO 13794:1999, 2.10]
2.11
Bertrand lens
intermediate lens which transfers an image of the back focal plane of the objective into the primary image plane
NOTE The Bertrand lens is used for conoscopic observation in polarized light microscopy and for adjustment of the
microscope illuminating system, especially in phase-contrast and modulation-contrast microscopy.
[3]
[ISO 10934-1:2002, 2.87.2]
2.12
birefringence
quantitative expression of the maximum difference in refractive index due to double refraction
[3]
[ISO 10934-1:2002, 2.16]
2.13
camera length
equivalent projection length between the specimen and its electron diffraction pattern, in the absence of lens action
[4]
[ISO 13794:1999, 2.12]
2.14
chrysotile
fibrous mineral of the serpentine group which has the nominal composition:
Mg Si O (OH)
3 2 5 4
NOTE Most natural chrysotile deviates little from this nominal composition. In some varieties of chrysotile, minor
3+ 3+ 2+ 3+ 2+ 2+ 2+
substitution of silicon by Al may occur. Minor substitution of magnesium by Al , Fe , Fe , Ni , Mn and Co may
also be present. Chrysotile is the most prevalent type of asbestos.
[4]
[ISO 13794:1999, 2.13]
2.15
cleavage
breaking of a mineral along one of its crystallographic directions
[4]
[ISO 13794:1999, 2.14]
2.16
cleavage fragment
fragment of a crystal that is bounded by cleavage faces
NOTE Crushing of non-asbestiform amphibole generally yields elongated fragments that conform to the definition of
a fibre, but rarely have aspect ratios exceeding 30:1.
2.17
crossed polars
state in which the polarization directions of the polars (polarizer and analyser) are mutually perpendicular
[3]
[ISO 10934-1:2002, 2.117.2]
2.18
d-spacing
distance between identical adjacent and parallel planes of atoms in a crystal
[4]
[ISO 13794:1999, 2.18]
2.19
dispersion
variation of refractive index with wavelength of light
[1]
[ISO 7348:1992, 05.03.26]
2.20
dispersion staining
effect produced when a transparent object is immersed in a surrounding medium, the refractive index of which
is equal to that of the object at a wavelength in the visible range, but which has a significantly higher optical
dispersion than the object
NOTE Only the light refracted at the edges of the object is imaged, and this gives rise to colours at the interface
between the object and the surrounding medium. The particular colour is a measure of the wavelength at which the
refractive index of the object and that of the medium are equal.
2.21
electron diffraction
technique in electron microscopy by which the crystal structure of a specimen is examined
[4]
[ISO 13794:1999, 2.19]
2.22
electron scattering power
extent to which a thin layer of substance scatters impinging electrons from their original directions
[4]
[ISO 13794:1999, 2.20]
2.23
energy dispersive X-ray analysis
EDXA
measurement of the energies and intensities of X-rays by use of a solid-state detector and multichannel
analyser system
[4]
[ISO 13794:1999, 2.22]
2.24
eucentric
condition in which the area of interest of an object is placed on a tilting axis, at the intersection of the electron
beam with that axis, and is in the plane of focus
[4]
[ISO 13794:1999, 2.23]
2.25
extinction
condition in which an optically anisotropic object appears dark when observed between crossed polars
[3]
[ISO 10934-1:2002, 2.51]
NOTE Extinction occurs when the vibration directions of the crystal are parallel to the vibration directions in the
polarizer and analyser.
2.26
extinction angle
angle between the extinction position and the position at which the length of a fibre is parallel to the polarizer
or analyser vibration directions
4 © ISO 2012 – All rights reserved
2.27
fibril
single fibre of asbestos which cannot be further separated longitudinally into smaller components without
losing its fibrous properties or appearances
[4]
[ISO 13794:1999, 2.25]
2.28
fibre
elongated particle which has parallel or stepped sides
[4]
[ISO 13794:1999, 2.26]
NOTE For the purposes of this part of ISO 22262, a fibre is defined to have an aspect ratio greater than or equal to 3:1.
2.29
fibre bundle
structure composed of parallel, smaller diameter fibres attached along their lengths
NOTE A fibre bundle may exhibit diverging fibres at one or both ends.
[4]
[ISO 13794:1999, 2.27]
2.30
gamma refractive index
γ
highest refractive index exhibited by a fibre
2.31
habit
characteristic crystal growth form, or combination of these forms, of a mineral, including characteristic
irregularities
[4]
[ISO 13794:1999, 2.30]
2.32
high-efficiency particulate air filter
HEPA
filter that is at least 99,97 % efficient by volume on 0,3 µm particles
[6]
[ISO 14952-1:2003, 2.13]
2.33
isotropic
having the same properties in all directions
[5]
[ISO 14686:2003, 2.23]
2.34
Köhler illumination
method of illuminating specimens in which an image of the illumination source is projected by a collector into
the plane of the aperture diaphragm in the front focal plane of the condenser, which then projects an image of
an illuminated field diaphragm at the opening of the collector into the specimen plane
2.35
lamda zero
λ
matching wavelength corresponding to the dispersion staining colour shown by a particle in an immersion medium
NOTE At this wavelength, the particle and the immersion medium have the same refractive index.
2.36
matrix
material in a laboratory sample within which fibres are dispersed
2.37
Miller index
set of either three or four integer numbers used to specify the orientation of a crystallographic plane in relation
to the crystal axes
[4]
[ISO 13794:1999, 2.33]
2.38
pleochroism
property of an optically anisotropic medium by which it exhibits different brightness and/or colour for different
directions of light propagation, or for different vibrations, on account of variation in selective spectral absorption
of transmitted light
2.39
polarized light
light in which the vibrations are partially or completely suppressed in certain directions at any given instant
NOTE The vector of vibration may describe a linear, circular or elliptical shape.
[3]
[ISO 10934-1:2002, 2.88.1]
2.40
polarizer
polar placed in the light path before the object
[3]
[ISO 10934-1:2002, 2.117.4]
2.41
polar
device which selects plane-polarized light from natural light
[3]
[ISO 10934-1:2002, 2.117]
2.42
refractive index
n
ratio of the speed of light (more exactly, the phase velocity) in a vacuum to that in a given medium
[3]
[ISO 10934-1:2002, 2.124]
2.43
retardation
difference in optical path length expressed in wavelengths, length units or phase angles between two mutually
perpendicular plane-polarized waves
[3]
[ISO 10934-1:2002, 2.128]
2.44
selected area electron diffraction
technique in electron microscopy in which the crystal structure of a small area of a sample is examined
[4]
[ISO 13794:1999, 2.38]
6 © ISO 2012 – All rights reserved
2.45
serpentine
group of common rock-forming minerals having the nominal formula:
Mg Si O (OH)
3 2 5 4
[4]
[ISO 13794:1999, 2.39]
2.46
sign of elongation
description of the directions of the high and low refractive indices in a fibre
NOTE The fibre is described as positive when the higher refractive index is parallel to the length of the fibre, and
negative when the lower refractive index is parallel to the length of the fibre.
2.47
temperature coefficient of refractive index
measure of the change of refractive index of a substance with temperature
2.48
twinning
occurrence of crystals of the same species joined together at a particular mutual orientation, and such that the
relative orientations are related by a definite law
[4]
[ISO 13794:1999, 2.41]
2.49
unopened fibre
large diameter asbestos fibre bundle that has not been separated into its constituent fibrils or fibres
[4]
[ISO 13794:1999, 2.42]
2.50
zone-axis
line or crystallographic direction through the centre of a crystal which is parallel to the intersection edges of the
crystal faces defining the crystal zone
[4]
[ISO 13794:1999, 2.43]
3 Symbols and abbreviated terms
dn
change of RI of an immersion medium per degree Celsius change of temperature
dT
n RI of a liquid for the sodium D line (589,3 nm) and at a temperature of 25 °C
D
α lowest RI of an anisotropic particle
β intermediate RI of an anisotropic particle
γ highest RI of an anisotropic particle
λ wavelength at which the RI of a particle is equal to the RI of the liquid in which it is immersed
ED electron diffraction
EDXA energy dispersive X-ray analysis
FWHM full width, half maximum
HEPA high-efficiency particle absolute
MEC mixed esters of cellulose
PC polycarbonate
PCOM phase contrast optical microscopy
PLM polarized light microscopy
RI refractive index
SAED selected area electron diffraction
SEM scanning electron microscopy
TEM transmission electron microscopy
4 Principle
4.1 General
A suitable tool is used, in compliance with the relevant safety regulations, to take a sample from the material to
be analysed. The sample is then appropriately packed and labelled for transportation to the laboratory.
A representative sample of the bulk material is initially examined using a stereo-binocular microscope.
Typical fibres are removed using tweezers and mounted in appropriate liquid immersion media on slides
for examination by polarized light microscopy. Asbestos fibres are identified based on morphology, colour,
pleochroism, and the α (lowest) and γ (highest) refractive indices qualitatively assessed using the dispersion
staining technique. Detection of commercial asbestos (chrysotile, amosite, crocidolite or anthophyllite), either
alone or in combination, is assumed to indicate that the asbestos is present at a mass fraction exceeding 0,1 %.
Optionally, a visual estimate of the asbestos mass fraction is reported in one of several broad mass fraction
ranges. Tremolite, actinolite and richterite/winchite are identified by the same procedure, but since they are
usually present as contaminants of mineral products, detection of these minerals does not provide information
as to their minimum mass fraction. Optionally, fibres may be identified by SEM or TEM.
4.2 Substance determination
This International Standard specifies a number of reference methods for determination of asbestos in
solid materials. This part of ISO 22262 provides a method for qualitative analysis of specific commercial
products for the presence of asbestos (chrysotile, amosite, crocidolite, tremolite, actinolite, anthophyllite and
richterite/winchite). Other parts of this International Standard provide methods for the analysis of specific types
of commercial products for which the use of PLM on the untreated sample yields unacceptable rates of error,
and for the quantification of asbestos in the low mass fraction range below approximately 5 %.
4.3 Type of sample
The method specified in this part of ISO 22262 is applicable to sampling and analysis of commercial products
from which individual fibres of asbestos can be manually separated from the matrix material, either by picking
fibres from surfaces and newly fractured surfaces, or after chemical treatments, acid extraction or ashing,
such that the fibres can be identified by one of the specified identification methods. This part of ISO 22262
is generally applicable to asbestos-containing building materials such as fireproofing, thermal pipe and boiler
insulations, asbestos cement, plasters, roofing, and other similar materials. The method is also applicable to
the identification of asbestos in a range of other industrial minerals and materials.
4.4 Range
Experience from proficiency testing has shown that the range of this part of ISO 22262, when it is applied to a
suitably prepared sample in which the asbestos fibres are sufficiently large to be optically visible using a low-
8 © ISO 2012 – All rights reserved
magnification stereomicroscope, is from less than 0,1 % to 100 %. The lower end of the range can be extended
downwards by use of appropriate techniques.
4.5 Limit of detection
The limit of detection of this method is defined as the detection and identification of one fibre or fibre bundle in
the amount of sample examined. The limit of detection that can be achieved depends on:
a) the nature of the matrix of the sample;
b) the size of the asbestos fibres and bundles;
c) the use of appropriate sample preparation and matrix reduction procedures;
d) the amount of time expended on examination of the sample;
e) the method of analysis used — PLM, SEM or TEM.
With appropriate matrix reduction procedures that are tailored to the nature of the sample, the limit of detection
can be significantly lower than 0,01 %.
4.6 Limitations of PLM in the detection of asbestos
The ability to detect and identify asbestos by PLM is limited by the resolution of the optical microscope and
sometimes by the masking effects of other materials that comprise the balance of the sample. Asbestos fibres
with widths below approximately 0,2 µm are unlikely to be detected by PLM. However, for all varieties of
amphibole asbestos, and most varieties of chrysotile, a large proportion of the mass comprises fibres that
exceed this width and, because of this, asbestos can be reliably detected by PLM. Accordingly, provided that
the nature of the matrix material on the microscope preparation is such that it does not obscure any asbestos
fibres that might be present, a non-detected result by PLM indicates that the mass fraction of asbestos is below
the limit of detection.
One commercial source of chrysotile presents problems of detection by PLM. Chrysotile originating from the
Coalinga deposit in California, USA, contains no fibrils longer than approximately 30 µm and, if these are well
dispersed in a sample matrix, the majority of the chrysotile is below the size that can be reliably detected and
identified by PLM. The range of application of Coalinga chrysotile is limited to floor tiles, ceiling tiles, drywall
joint compounds, mastics, paints, sealants, adhesives, drilling mud, moulded cement building products, and
as filler in some plastics. There is a high probability that this variety of chrysotile may not be detected by PLM,
even when present in high mass fractions. The size distribution of Coalinga chrysotile makes it unsuitable for
most other applications in which asbestos was used and the possibility that it will be encountered in other types
of product can generally be discounted. If, on the basis of PLM examination, Coalinga chrysotile is suspected
to be present, it is recommended that the sample be examined by electron microscopy.
Asbestos fibres may not be detected by PLM because they are obscured by the matrix of the sample. The
matrix reduction methods specified in this part of ISO 22262 are intended to minimize the possibility of failing
to detect asbestos in such samples.
5 Sample collection
5.1 Requirements
5.1.1 Sampling apparatus. Depending on the nature of the material to be sampled, an appropriate tool is
required for collection of the sample. If the material is soft, such as thermal insulation or fireproofing, a knife or
scalpel may be sufficient. In other situations, a cork borer may be used to sample all of the layers of a layered
material. If the material is hard, e.g. asbestos–cement, tools such as pliers, a wire cutter, hammer and chisel or
rotating hole saw can be needed.
5.1.2 HEPA vacuum cleaner. A HEPA vacuum cleaner, approved for asbestos, is required for cleaning
around the sampling location after collection of the sample to minimize dispersion of asbestos-containing dust
or particulate matter.
5.1.3 Materials and supplies for sampling.
5.1.3.1 Wetting agent. A wetting agent may be used to limit the generation of airborne dust during the
collection of the sample. Water, or water to which a small amount of surfactant has been added, may be applied
to the surface before sampling using a spray bottle or brush.
IMPORTANT If a sample is being collected for the purpose of product identification, use no wetting
agent, since this may result in alteration of the sample composition by addition of surfactant, and by
dissolution and loss of water-soluble constituents.
5.1.3.2 Filler. After collection of the sample, a minor repair may be necessary to seal the damaged area.
Depending on the circumstances, spray paint, touch-up paint or plaster may be used.
5.1.3.3 Sample containers. Appropriate dust-tight containers are required for packaging the sample. Plastic
bags with “zip” closures or bottles with screw caps may be used.
5.1.3.4 Labels. A method for labelling samples is required. Self-adhesive paper labels may be used.
Alternatively, a waterproof marker may be sufficient for field use.
5.1.3.5 Dust mask. A dust mask with filter approved for respiratory protection against airborne asbestos
fibres. Approved filters conform to either the National Institute for Occupational Safety and Health (NIOSH)
[9]
P100 or the European Standard EN 143 P3 specification. Other types of personal protective equipment may
be used if warranted by the situation.
5.1.3.6 Light. Either a flashlight or an appropriate light source is required for collection of samples in dark locations.
5.1.3.7 Plastic bags. Labelled plastic bags of appropriate size that can be closed tightly and are required
to collect the waste generated during sampling. Bags containing waste should be placed inside another tightly
closed plastic bag.
5.1.3.8 Cleaning supplies. Cleaning materials, such as disposable paper towels and a supply of water, are
required for cleaning sampling tools to avoid cross-contamination between samples.
5.1.3.9 Location identifiers. The use of some means of identifying the precise location from which each
sample is taken is recommended, since it may be necessary to resample the material at a later date to resolve
discrepancies if they arise. A location identifier is invaluable if the sample collected is found not to be representative
of the overall area, such as if the sample has been taken from a patch in a location that has been repaired. A
specific colour of spray paint, or appropriate permanent labels applied to the precise location, may be used.
5.2 Procedure
5.2.1 Safety precautions
Handling asbestos is regulated by many jurisdictions, and regulations often specify a variety of procedures to
ensure that individuals performing work and those in close proximity are not exposed to excessive concentrations
of airborne asbestos. Exceptions from the regulations are generally permitted for some types of activity that are
minimally invasive, such as the removal of material samples for analysis.
IMPORTANT — Care is necessary during sampling of materials that may contain asbestos, and precautions
should be taken to avoid creating and inhaling airborne asbestos particles when sampling materials
suspected of containing asbestos. If the handling instructions in this clause are followed, it may be
10 © ISO 2012 – All rights reserved
assumed that the level of dust meets the thresholds of safety defined in the regulations. In exceptional
cases, more extensive precautions may be necessary to prevent the release of airborne fibres.
Sometimes different materials may have been applied to a surface as several layers. It is recommended that
samples of all of the individual layers be collected. If a borer or hole-sawing device is used to penetrate several
layers, the device should be operated so that it rotates slowly. This ensures that only coarse turnings are
produced. High-speed devices are not recommended, since it is then necessary to take more complex safety
precautions such as local suction and filtration to collect the dust generated.
5.2.2 Sample size requirements
5.2.2.1 General
Although only a few milligrams of sample are required for the analytical methods specified, it is necessary
to take into account the homogeneity of the material, and to ensure that the sample is of sufficient size to be
representative of the material under investigation. If inspection shows that the material is finely divided and
homogeneous when examined visually, or if the nature of the material is recognized as such from previous
knowledge, a minimum sample size of approximately 1 cm generally provides sufficient material for analysis.
However, a minimum volume of 10 cm is recommended for materials such as sprayed fireproofing, and as
much as 1 000 cm for materials such as loose-fill vermiculite.
5.2.2.2 Representative sample
A wide range of asbestos-containing materials was used in the past. Experience is very valuable in the selection
of the materials to be sampled and sampling can be facilitated by the use of all available prior knowledge
about the materials or component
...
NORME ISO
INTERNATIONALE 22262-1
Première édition
2012-07-01
Qualité de l’air — Matériaux solides —
Partie 1:
Échantillonnage et dosage qualitatif de
l’amiante dans les matériaux solides
d’origine commerciale
Air quality — Bulk materials —
Part 1: Sampling and qualitative determination of asbestos in
commercial bulk materials
Numéro de référence
©
ISO 2012
DOCUMENT PROTÉGÉ PAR COPYRIGHT
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l’accord écrit
de l’ISO à l’adresse ci-après ou du comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
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Publié en Suisse
ii © ISO 2012 – Tous droits réservés
Sommaire Page
Avant-propos . v
Introduction .vi
1 Domaine d’application . 1
2 Termes et définitions . 1
3 Symboles et termes abrégés . 8
4 Principe . 8
4.1 Généralités . 8
4.2 Détection de la substance . 9
4.3 Type d’échantillon . 9
4.4 Étendue de mesure . 9
4.5 Limite de détection . 9
4.6 Limitations du MOLP dans la détection de l’amiante . 9
5 Prélèvement de l’échantillon .10
5.1 Exigences .10
5.2 Mode opératoire . 11
6 Préparation de l’échantillon .15
6.1 Généralités .15
6.2 Élimination des matériaux organiques par calcination .15
6.3 Élimination des constituants solubles par traitement à l’acide .15
6.4 Sédimentation et flottation.15
6.5 Combinaison des procédures de réduction gravimétrique .16
7 Analyse par MOLP .16
7.1 Exigences .16
7.2 Analyse qualitative par MOLP .20
8 Analyse par MEB .31
8.1 Généralités .31
8.2 Exigences .31
8.3 Étalonnage .32
8.4 Préparation de l’échantillon .32
8.5 Analyse qualitative par MEB .32
9 Analyse par microscope électronique à transmission .34
9.1 Généralités .34
9.2 Exigences .34
9.3 Étalonnage .35
9.4 Préparation de l’échantillon .35
9.5 Analyse qualitative par MET .36
10 Rapport d’essai .37
Annexe A (normative) Types de matériaux contenant de l’amiante d’origine commerciale .39
Annexe B (normative) Échelle des teintes d’interférence .43
Annexe C (normative) Échelle des couleurs de dispersion .44
Annexe D (normative) Identification de l’amiante par MOLP et dispersion de coloration dans les
matériaux d’origine commerciale .46
Annexe E (normative) Identification de l’amiante par MEB dans les matériaux d’origine commerciale .55
Annexe F (normative) Identification de l’amiante par MET dans les matériaux d’origine commerciale .61
Annexe G (informative) Exemple de rapport d’échantillonnage .70
Annexe H (informative) Exemple de rapport d’essai .71
Bibliographie .72
iv © ISO 2012 – Tous droits réservés
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes nationaux de
normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est en général confiée aux
comités techniques de l’ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du comité
technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales,
en liaison avec l’ISO participent également aux travaux. L’ISO collabore étroitement avec la Commission
électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI, Partie 2.
La tâche principale des comités techniques est d’élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur publication
comme Normes internationales requiert l’approbation de 75 % au moins des comités membres votants.
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de droits
de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable de ne pas avoir
identifié de tels droits de propriété et averti de leur existence.
L’ISO 22262-1 a été élaborée par le comité technique ISO/TC 146, Qualité de l’air, sous-comité SC 3,
Atmosphères ambiantes.
L’ISO 22262 comprend les parties suivantes, présentées sous le titre général Qualité de l’air — Matériaux solides:
— Partie 1: Échantillonnage et dosage qualitatif de l’amiante dans les matériaux solides d’origine commerciale
La partie suivante est en cours d’élaboration:
— Partie 2: Dosage quantitatif de l’amiante en utilisant les méthodes gravimétrique et microscopique
Introduction
L’amiante était auparavant utilisé dans une vaste gamme de produits. Trois variétés d’amiante ont été très
utilisées dans le commerce. Le chrysotile représentait environ 95 % de la consommation. Il est donc la variété
la plus fréquemment rencontrée lors de l’analyse des échantillons. Des matériaux contenant de grandes
proportions de chrysotile étaient utilisés dans les secteurs de la construction et de l’industrie pour l’ignifugation,
l’isolation thermique et l’isolation phonique. Le chrysotile était également utilisé pour renforcer les matériaux
et pour améliorer les caractéristiques de rupture et de flexion. Une grande proportion du chrysotile produit
était utilisée dans les produits en amiante-ciment, notamment les plaques planes, les tuiles et les plaques
ondulées pour la couverture, les tuyaux et gouttières pour la récupération d’eau de pluie ainsi que les tuyaux
sous pression pour l’alimentation en eau potable. Le chrysotile était également incorporé dans des produits
tels que les revêtements et les enduits décoratifs, les colles, les mastics, les résines, les dalles, les joints
et les revêtements routiers. Dans certains produits, du chrysotile était ajouté pour modifier les propriétés
rhéologiques, par exemple dans la fabrication de panneaux de faux plafond et les boues de forage pétrolier. Le
chrysotile de qualité textile (longue fibre) était également utilisé pour fabriquer des produits tissés, filés, feutrés
et en papier.
L’amosite et la crocidolite représentaient la quasi-totalité du reste. L’amosite était généralement utilisée comme
matériau ignifuge ou dans les produits d’isolation thermique, tels que calorifugeage de tuyaux et panneaux
isolants. La crocidolite était également utilisée comme matériau ignifuge et dans les produits d’isolation
thermique; en outre, elle était particulièrement prisée pour sa grande résistance aux acides, était suffisamment
souple pour se prêter au filage et présentait une grande résistance à la traction. La crocidolite était également
employée comme fibre de renfort dans les récipients d’acide tels que ceux utilisés pour les accumulateurs au
plomb, dans des textiles de haute performance et dans des joints. Elle a également joué un rôle important dans
la fabrication de canalisations haute pression en amiante-ciment pour l’alimentation en eau potable.
Trois autres types d’amiante sont actuellement soumis à réglementation. Les matériaux contenant de
l’anthophyllite d’origine commerciale sont relativement rares, mais ils ont également été utilisés comme
colmatant et fibre de renfort dans les matériaux composites, et comme milieu filtrant. L’amiante trémolite et
l’amiante actinote ont été peu utilisés dans le commerce, mais la présence d’amiante trémolite a été parfois
détectée dans des matériaux de surfaçage et des matériaux ignifuges au Japon. L’amiante trémolite et l’amiante
actinote ont parfois été le résultat d’une contamination d’autres minéraux commercialisés. D’autres minéraux
peuvent également apparaître sous forme d’amiante. Par exemple, l’amiante richtérite et l’amiante winchite
apparaissent à des fractions massiques comprises entre 0,1 % et 6% dans la vermiculite anciennement
extraite de la mine de Libby, Montana, États-Unis. La vermiculite de cette origine a été largement distribuée
et sert souvent d’isolant en vrac et de constituant dans une vaste gamme de matériaux de construction et de
matériaux ignifuges.
Alors que la fraction massique d’amiante dans certains produits peut être très élevée et approcher parfois
les 100 %, les fractions massiques d’amiante dans d’autres produits étaient nettement inférieures et souvent
comprises entre 1 % et 15 %. Dans certains panneaux de faux plafond, la fraction massique d’amiante
utilisée était proche de 1 %. Il n’existe que quelques matériaux connus dans lesquels la fraction massique
d’amiante était inférieure à 1 %. Certains adhésifs, produits d’étanchéité et mastics ont été fabriqués avec des
fractions massiques d’amiante inférieures à 1 %. On ne connaît aucun matériau dans lequel de l’amiante a été
intentionnellement ajouté à des fractions massiques inférieures à 0,1 %.
Dans la présente partie de l’ISO 22262 sont décrites les procédures de prélèvement d’échantillons et d’analyse
qualitative des matériaux solides d’origine commerciale pour la détection d’amiante. La microscopie en
lumière polarisée constitue la principale méthode d’identification de l’amiante. En raison de la vaste gamme
de matériaux matriciels dans lesquels de l’amiante a été incorporé, la microscopie en lumière polarisée ne
permet pas d’effectuer des analyses fiables de tous les types de matériaux contenant de l’amiante dans les
échantillons non traités. L’applicabilité de la microscopie en lumière polarisée peut être élargie en utilisant des
traitements simples tels que la calcination et le traitement à l’acide. Pour identifier l’amiante, il est également
possible d’utiliser la microscopie électronique à balayage ou la microscopie électronique à transmission comme
méthode alternative ou de confirmation.
Bien que la présente partie de l’ISO 22262 spécifie qu’une estimation visuelle de la concentration en
amiante peut éventuellement être réalisée dans de très vastes gammes, il est reconnu que l’exactitude
et la reproductibilité de ces estimations sont très limitées. La procédure de quantification de la teneur en
vi © ISO 2012 – Tous droits réservés
amiante peut être nécessaire pour un certain nombre de raisons telles que, par exemple, l’évaluation et la
gestion du risque lié aux matériaux contenant de l’amiante dans les bâtiments pour répondre aux définitions
réglementaires relatives aux matériaux contenant de l’amiante. La nécessité de quantifier la teneur en amiante
dans un matériau dépend de la fraction massique maximale adoptée par la réglementation pour définir un
matériau contenant de l’amiante à des fins de réglementation. Les définitions vont de «tout amiante» jusqu’à
0,1 %, 0,5 % ou 1 %. Pour les réglementations dans lesquelles un matériau contenant de l’amiante est défini
comme contenant «tout amiante», il se pose un problème particulier concernant la manière de déterminer si un
matériau contient ou non de l’amiante, car toutes les méthodes ont des limites de détection.
Pour des raisons pratiques, étant donné qu’on ne connaît aucun matériau commercial dans lequel de l’amiante
d’origine commerciale a été intentionnellement ajouté à des fractions massiques inférieures à 0,1 %, la présente
partie de l’ISO 22262 spécifie que les échantillons doivent être classés comme contenant de l’amiante (c’est-
à-dire contenant plus de 0,1 % d’amiante) si du chrysotile, de l’amosite, de la crocidolite ou de l’anthophyllite,
ou des combinaisons de ces variétés, sont détectés au cours de l’analyse. Lorsque les matériaux contenant
de l’amiante sont définis comme étant des matériaux contenant 0,5 % ou 1 % d’amiante, selon la nature du
produit, il est souvent nécessaire de se référer aux autres parties de l’ISO 22262 pour quantifier l’amiante afin
de définir le statut réglementaire des matériaux.
La présence de trémolite, d’actinote ou de richtérite/winchite dans un matériau est en général le résultat de la
contamination naturelle des constituants, et la détection de ces minéraux ne signifie pas nécessairement que la
fraction massique d’amiante est supérieure à 0,1 %. En conséquence, il arrive souvent que la détermination du
statut réglementaire de ces matériaux par l’un quelconque des critères ne puisse se faire que par une analyse
quantitative. Ces minéraux n’ayant pas été spécifiquement extraits des mines et utilisés pour leurs propriétés
fibreuses, ils peuvent également apparaître dans les matériaux comme des analogues non asbestiformes ou
asbestiformes, ou comme un mélange des deux. L’évaluation de ces types de matériaux peut requérir une
analyse plus détaillée.
Les procédures d’analyse simples, telles que la microscopie en lumière polarisée, ne permettent pas de détecter
ou d’identifier de manière fiable l’amiante contenu dans certains types de produits commerciaux comprenant
des matériaux contenant de l’amiante; soit parce que la taille des fibres est inférieure à la résolution de la
microscopie optique, soit parce que le matériau matriciel adhère trop aux fibres. Pour ces types de produits, il
peut être nécessaire d’utiliser la microscopie électronique.
Voir l’Avant-propos pour la liste des autres parties de la présente Norme internationale.
[11]
La méthode spécifiée dans la présente partie de l’ISO 22262 s’appuie sur les documents MDHS 77 ,
[13] [14] [15] [8] [10]
VDI 3866 Partie 1 , VDI 3866 Partie 4 , VDI 3866 Partie 5 , AS 4964-2004 , EPA/600/R-93/116
[12]
et NF X46-020:2008 .
NORME INTERNATIONALE ISO 22262-1:2012(F)
Qualité de l’air — Matériaux solides —
Partie 1:
Échantillonnage et dosage qualitatif de l’amiante dans les
matériaux solides d’origine commerciale
IMPORTANT — Le fichier électronique du présent document contient des couleurs qui sont jugées
utiles pour la bonne compréhension du document. Il convient donc aux utilisateurs de considérer
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1 Domaine d’application
La présente partie de l’ISO 22262 spécifie les méthodes d’échantillonnage de matériaux solides et d’identification
de l’amiante dans les matériaux solides d’origine commerciale. La présente partie de l’ISO 22262 spécifie
les procédures appropriées de préparation de l’échantillon et décrit en détail la procédure d’identification de
l’amiante par microscopie en lumière polarisée et dispersion de coloration.
La présente partie de l’ISO 22262 spécifie également des procédures simples de séparation des fibres
d’amiante des matériaux matriciels tels que les produits bitumineux, à base de ciment et de plastique.
L’identification de l’amiante peut également être effectuée en utilisant la microscopie électronique à balayage
ou la microscopie électronique à transmission avec analyse en dispersion d’énergie des rayons X. Des
informations sont également données sur les problèmes habituels d’analyse, les interférences et autres types
de fibres susceptibles d’être rencontrés au cours de l’analyse.
La présente partie de l’ISO 22262 est applicable à l’identification qualitative de l’amiante dans des types
spécifiques de produits manufacturés et de minéraux commercialisés contenant de l’amiante. La présente
partie de l’ISO 22262 est applicable à l’analyse des matériaux ignifuges, produits d’isolation thermique et
autres produits manufacturés ou minéraux dans lesquels les fibres d’amiante peuvent être facilement séparées
des matériaux matriciels pour être identifiées.
NOTE La présente partie de l’ISO 22262 est destinée à être utilisée par les microscopistes familiarisés avec les
méthodes de microscopie en lumière polarisée et par les personnes chargées de l’analyse, expérimentées et familiarisées
avec les procédures d’analyse spécifiées (Références [16] à [19]). L’objectif de la présente partie de l’ISO 22262 n’est pas
de fournir des informations sur les techniques d’analyse fondamentale.
2 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
2.1
achromat
objectif de microscope dans lequel l’aberration chromatique est corrigée pour deux longueurs d’onde et
l’aberration sphérique, ainsi que les autres défauts dépendant de l’ouverture, sont minimisés pour une autre
longueur d’onde (généralement environ 550 nm)
EXEMPLE Une longueur d’onde inférieure à 500 nm environ, l’autre supérieure à 600 nm environ.
NOTE Ce terme n’implique pas un degré quelconque de correction pour la courbure du champ d’image; la coma et
l’astigmatisme sont minimisés pour les longueurs d’ondes situées dans la gamme achromatique.
[3]
[ISO 10934-1:2002 , 2.6]
2.2
aciculaire
forme présentée par un cristal extrêmement fin dont les dimensions transversales sont petites par rapport à sa
longueur, c’est-à-dire en forme d’aiguille
[4]
[ISO 13794:1999 , 2.1]
2.3
indice de réfraction alpha
α
indice de réfraction minimal présenté par une fibre
2.4
amphibole
groupe de minéraux cardinaux de silicate de ferromagnésium, étroitement proches en termes de forme et de
composition cristallines, et de formule nominale:
A B C T O (OH,F,Cl)
0-1 2 5 8 22 2
où
A est K, Na;
2+
B est Fe , Mn, Mg, Ca, Na;
3+ 2+
C est Al, Cr, Ti, Fe , Mg, Fe ;
3+
T est Si, Al, Cr, Fe , Ti
NOTE Dans certaines variétés d’amphibole, ces éléments peuvent être partiellement substitués par Li, Pb ou Zn.
L’amphibole est caractérisée par une double chaîne de tétraèdres Si-O avec un rapport silicium:oxygène de 4:11, par des
cristaux prismatiques fibreux ou en colonnes et par un clivage prismatique bien marqué dans deux directions parallèles
aux faces du cristal et se coupant à des angles d’environ 56° et 124°.
[4]
[ISO 13794:1999 , 2.2]
2.5
amiante amphibole
amphibole de forme asbestiforme
[4]
[ISO 13794:1999 , 2.3]
2.6
analyseur
polaroïd placé après l’objet pour déterminer les effets optiques produits par l’objet sur la lumière, polarisée ou
autre, qui l’éclaire
NOTE L’analyseur est placé généralement entre l’objectif et le plan d’image primaire.
[3]
[ISO 10934-1:2002 , 2.117.1]
2.7
anisotropie
état ou qualité d’avoir des caractéristiques différentes selon des axes différents
EXEMPLE Une particule transparente anisotrope peut avoir différents indices de réfraction en fonction de la direction
de vibration de la lumière incidente.
2 © ISO 2012 – Tous droits réservés
2.8
asbestiforme
type de fibrosité minérale spécifique dans lequel les fibres et les fibrilles possèdent une résistance à la traction
et une flexibilité élevées
[4]
[ISO 13794:1999 , 2.6]
2.9
amiante
terme s’appliquant à un groupe de minéraux de silicates appartenant aux groupes des amphiboles et des
serpentines qui se sont cristallisés en faciès asbestiforme, ce qui permet, lorsqu’ils sont traités ou broyés, de
les séparer facilement en fibres longues, minces, flexibles et solides
NOTE 1 Les numéros de registre CAS des variétés d’amiante les plus courantes sont: chrysotile (12001-29-5),
crocidolite (12001-28-4), amiante grunérite (amosite) (12172-73-5), amiante anthophyllite (77536-67-5), amiante trémolite
(77536-68-6) et amiante actinote (77536-66-4).
[4]
[ISO 13794:1999 , 2.7]
NOTE 2 D’autres variétés d’amphibole asbestiforme, notamment l’amiante richtérite et l’amiante winchite
(Référence [20]), sont également présentes dans certains produits tels que la vermiculite et le talc.
2.10
rapport largeur/longueur
rapport de la longueur d’une particule à sa largeur
[4]
[ISO 13794:1999 , 2.10]
2.11
lentille de Bertrand
lentille intermédiaire qui transfère une image du foyer-image de l’objectif sur le plan d’image primaire
NOTE La lentille de Bertrand est utilisée pour observation conoscopique en microscopie de polarisation et pour réglage
du système d’éclairage d’un microscope, notamment en microscopie à contraste de phase et à contraste de modulation.
[3]
[ISO 10934-1:2002 , 2.87.2]
2.12
biréfringence
expression quantitative de la différence maximale dans l’indice de réfraction due à la double réfraction
[3]
[ISO 10934-1:2002 , 2.16]
2.13
longueur de caméra
longueur de projection équivalente entre l’échantillon et son diagramme de diffraction électronique, en l’absence
d’action de la lentille
[4]
[ISO 13794:1999 , 2.12]
2.14
chrysotile
minéral fibreux du groupe des serpentines, de composition nominale:
Mg Si O (OH)
3 2 5 4
NOTE La majeure partie du chrysotile naturel possède une composition nominale proche de celle-ci. Dans certaines
3+
variétés de chrysotile, une substitution mineure du silicium par Al peut survenir. Une substitution mineure du magnésium
3+ 2+ 3+ 2+ 2+ 2+
par Al , Fe , Fe , Ni , Mn et Co peut également se produire. Le chrysotile est le principal type d’amiante.
[4]
[ISO 13794:1999 , 2.13]
2.15
clivage
fissuration d’un minéral dans une de ses directions cristallographiques
[4]
[ISO 13794:1999 , 2.14]
2.16
fragment de clivage
fragment d’un cristal lié par les faces de clivage
NOTE En général, le broyage de l’amphibole non asbestiforme produit des fragments allongés conformes à la
définition d’une fibre, mais dont les rapports largeur/longueur dépassent rarement 30:1.
2.17
polaroïds croisés
état dans lequel les directions de polarisation des polaires (polariseur et analyseur) sont perpendiculaires
l’une à l’autre
[3]
[ISO 10934-1:2002 , 2.117.2]
2.18
espacement d
distance entre des plans adjacents et parallèles identiques d’atomes dans un cristal
[4]
[ISO 13794:1999 , 2.18]
2.19
dispersion
variation de l’indice de réfraction en fonction de la longueur d’onde de la lumière
[1]
[ISO 7348:1992 , 05.03.26]
2.20
dispersion de coloration
effet produit lorsqu’un objet transparent est immergé dans un milieu environnant, dont l’indice de réfraction
est égal à celui de l’objet à une longueur d’onde dans la gamme visible, mais dont la dispersion optique est
nettement supérieure à l’objet
NOTE Seule la lumière réfractée aux bords de l’objet apparaît sur l’image, ce qui produit des couleurs au niveau de
l’interface entre l’objet et le milieu environnant. La couleur particulière est une mesure de la longueur d’onde à laquelle
l’indice de réfraction de l’objet et celui du milieu sont égaux.
2.21
diffraction électronique
technique de microscopie électronique consistant à examiner la structure cristalline d’un échantillon
[4]
[ISO 13794:1999 , 2.19]
2.22
puissance de diffusion des électrons
degré de diffusion des électrons d’une mince couche de substance depuis leurs directions d’origine
[4]
[ISO 13794:1999 , 2.20]
2.23
analyse en dispersion d’énergie des rayons X
EDXA
mesure des énergies et des intensités des rayons X à l’aide d’un détecteur à semi-conducteurs et d’un
analyseur multicanal
[4]
[ISO 13794:1999 , 2.22]
4 © ISO 2012 – Tous droits réservés
2.24
eucentrique
condition dans laquelle la région d’intérêt d’un objet est placée sur un axe de basculement, à l’intersection du
faisceau d’électrons et de cet axe, et se trouve dans le plan focal
[4]
[ISO 13794:1999 , 2.23]
2.25
extinction
condition dans laquelle un objet optiquement anisotrope apparaît foncé lorsqu’il est observé entre polaroïds croisés
[3]
[ISO 10934-1:2002 , 2.51]
NOTE L’extinction se produit lorsque les directions de vibration du cristal sont parallèles aux directions de vibration
du polariseur et de l’analyseur.
2.26
angle d’extinction
angle entre la position d’extinction et la position à laquelle la longueur d’une fibre est parallèle aux directions
de vibration du polariseur ou de l’analyseur
2.27
fibrille
fibre d’amiante unique, qui ne peut pas être davantage séparée dans le sens longitudinal en de plus petits
composants sans perdre ses propriétés ou ses aspects fibreux
[4]
[ISO 13794:1999 , 2.25]
2.28
fibre
particule allongée dont les côtés sont parallèles ou étagés
[4]
[ISO 13794:1999 , 2.26]
NOTE Pour les besoins de la présente partie de l’ISO 22262, une fibre est définie comme ayant un rapport
largeur/longueur supérieur ou égal ou 3:1.
2.29
faisceau de fibres
structure composée de fibres parallèles de diamètre inférieur attachées sur leur longueur
NOTE Un faisceau de fibres peut présenter des fibres divergentes à une ou deux extrémités.
[4]
[ISO 13794:1999 , 2.27]
2.30
indice de réfraction gamma
γ
indice de réfraction minimal présenté par une fibre
2.31
habitus
forme de croissance cristalline caractéristique d’un minéral ou combinaison de ces formes, notamment les
irrégularités caractéristiques
[4]
[ISO 13794:1999 , 2.30]
2.32
filtre à haute efficacité pour les particules de l’air
HEPA
filtre efficace à au moins 99,97 % en volume pour les particules de 0,3 µm
[6]
[ISO 14952-1:2003 , 2.13]
2.33
isotrope
qui a les mêmes propriétés dans toutes les directions
[5]
[ISO 14686:2003 , 2.23]
2.34
éclairage Köhler
méthode d’éclairage d’échantillons dans laquelle une image de la source d’éclairage est projetée par un
collecteur dans le plan du diaphragme d’ouverture dans le premier plan focal du condensateur, qui projette
ensuite une image d’un diaphragme de champ éclairé au niveau de l’ouverture du collecteur dans le plan de
l’échantillon
2.35
lambda zéro
λ
longueur d’onde de la couleur de dispersion de coloration présentée par une particule dans un milieu d’immersion
NOTE À cette longueur d’onde, la particule et le milieu d’immersion ont le même indice de réfraction.
2.36
matrice
matériau dans un échantillon pour laboratoire dans lequel les fibres sont dispersées
2.37
indice de Miller
groupe de trois ou quatre nombres entiers utilisés pour spécifier l’orientation d’un plan cristallographique par
rapport aux axes du cristal
[4]
[ISO 13794:1999 , 2.33]
2.38
pléochroïsme
propriété d’un milieu optiquement anisotrope par laquelle il présente une luminosité et/ou couleur différente
pour diverses directions de propagation de la lumière ou pour diverses vibrations, en raison de la variation
d’absorption spectrale sélective de la lumière transmise
2.39
lumière polarisée
lumière dans laquelle les vibrations sont partiellement ou complètement supprimées dans certaines directions
à tout instant donné
NOTE Le vecteur de vibration peut décrire une forme linéaire, circulaire ou elliptique.
[3]
[ISO 10934-1:2002 , 2.88.1]
2.40
polariseur
polaroïd placé dans la marche de la lumière devant l’objet
[3]
[ISO 10934-1:2002 , 2.117.4]
2.41
polaroïd
tout dispositif qui sélectionne une lumière à polarisation plane à partir de la lumière naturelle
[3]
[ISO 10934-1:2002 , 2.117]
6 © ISO 2012 – Tous droits réservés
2.42
indice de réfraction
n
rapport entre la vitesse de la lumière (plus exactement la vélocité de phase) dans un vide et celle dans
un milieu donné
[3]
[ISO 10934-1:2002 , 2.124]
2.43
retard
différence de longueurs de parcours optique, exprimée en longueurs d’onde, unités de longueur ou angles de
phase, entre deux ondes polarisées perpendiculaires l’une à l’autre
[3]
[ISO 10934-1:2002 , 2.128]
2.44
diffraction électronique en aire sélectionnée
technique de microscopie électronique consistant à examiner la structure cristalline d’une petite aire d’un échantillon
[4]
[ISO 13794:1999 , 2.38]
2.45
serpentine
groupe de minéraux cardinaux courants de formule nominale:
Mg Si O (OH)
3 2 5 4
[4]
[ISO 13794:1999 , 2.39]
2.46
signe d’allongement
description des directions des indices de réfraction élevés et faibles dans une fibre
NOTE La fibre est décrite comme étant positive lorsque l’indice de réfraction supérieur est parallèle à la longueur de
la fibre, et négative lorsque l’indice de réfraction inférieur est parallèle à la longueur de la fibre.
2.47
coefficient de température de l’indice de réfraction
mesure du changement d’indice de réfraction d’une substance en fonction de la température
2.48
macle
formation de cristaux de la même espèce accolés selon une orientation mutuelle particulière, et telle que les
orientations relatives obéissent à une règle définie
[4]
[ISO 13794:1999 , 2.41]
2.49
fibre non ouverte
faisceau de fibres d’amiante de diamètre élevé qui n’a pas été séparé en ses fibrilles ou fibres constituantes
[4]
[ISO 13794:1999 , 2.42]
2.50
axe de zone
ligne ou direction cristallographique à travers le centre d’un cristal qui est parallèle aux faces d’intersection des
plans d’un cristal définissant la zone cristalline
[4]
[ISO 13794:1999 , 2.43]
3 Symboles et termes abrégés
changement d’IR d’un milieu d’immersion par degré Celsius de variation de température
dn
dT
IR d’un liquide pour la ligne D du sodium (589,3 nm) et à une température de 25 °C
n
D
α
IR minimal d’une particule anisotrope
β
IR intermédiaire d’une particule anisotrope
γ
IR maximal d’une particule anisotrope
λ longueur d’onde à laquelle l’IR d’une particule est égal à l’IR du liquide dans lequel elle est
immergée
DE diffraction électronique
EDXA analyse en dispersion d’énergie des rayons X
LMH largeur à mi-hauteur
HEPA filtre à haute efficacité pour les particules de l’air
MEC mélange d’esters de cellulose
PC polycarbonate
MOCP microscopie optique à contraste de phase
MOLP microscopie en lumière polarisée
IR indice de réfraction
SAED diffraction électronique en aire sélectionnée
MEB microscope électronique à balayage
MET microscope électronique à transmission
4 Principe
4.1 Généralités
Conformément aux règles de sécurité applicables, un outil approprié est utilisé pour prélever un échantillon du
matériau à analyser. L’échantillon est ensuite adéquatement emballé et étiqueté pour être envoyé au laboratoire.
Un échantillon représentatif du matériau solide est d’abord examiné à l’aide d’un stéréo-microscope binoculaire.
Les fibres types sont retirées avec des pinces et placées dans un milieu d’immersion liquide approprié sur des
lames, pour être examinées par microscopie en lumière polarisée. Les fibres d’amiante sont identifiées d’après
la morphologie, la couleur, le pléochroïsme et les indices de réfraction α (minimaux) et γ (maximaux) évalués
de manière qualitative en utilisant la technique de dispersion de coloration. La détection d’amiante d’origine
commerciale (chrysotile, amosite, crocidolite ou anthophyllite), seul ou en mélange, est censée indiquer que
la fraction massique d’amiante est supérieure à 0,1 %. Facultativement, une estimation visuelle de la fraction
massique d’amiante est réalisée dans l’une des nombreuses et larges gammes de fractions massiques. La
trémolite, l’actinote et la richtérite/winchite sont identifiées en utilisant la même procédure. Toutefois, étant
donné que leur présence est généralement le résultat de la contamination des produits minéraux, la détection de
ces minéraux ne fournit pas d’informations sur leur fraction massique minimale. Les fibres peuvent également
être identifiées par MEB ou MET.
8 © ISO 2012 – Tous droits réservés
4.2 Détection de la substance
L’ISO 22262 spécifie plusieurs méthodes de référence pour détecter l’amiante dans les matériaux solides.
La présente partie de l’ISO 22262 fournit une méthode d’analyse qualitative de produits commerciaux
spécifiques pour la présence d’amiante (chrysotile, amosite, crocidolite, trémolite, actinote, anthophyllite et
richtérite/winchite). Les autres parties de l’ISO 22262 fournissent des méthodes d’analyse de types de produits
commerciaux spécifiques pour lesquels l’utilisation de la MOLP sur l’échantillon non traité engendre des taux
d’erreur inacceptables, et des méthodes de quantification de l’amiante dans la gamme de fractions massiques
basse inférieure à environ 5 %.
4.3 Type d’échantillon
La méthode spécifiée dans la présente partie de l’ISO 22262 est applicable à l’échantillonnage et à l’analyse
des produits commerciaux dont les fibres individuelles d’amiante peuvent être séparées manuellement du
matériau matriciel, soit en prélevant les fibres des surfaces et des surfaces fraîchement cassées, soit après
traitement chimique, extraction acide ou calcination, de sorte que les fibres peuvent être identifiées à l’aide
des méthodes d’identification spécifiées. La présente partie de l’ISO 22262 est généralement applicable
aux matériaux de construction contenant de l’amiante tels que les matériaux ignifuges, les joints de tuyaux
thermiques et de chaudières, l’amiante-ciment, les enduits, les matériaux de couverture et d’autres matériaux
similaires. La méthode est également applicable pour l’identification d’amiante dans une gamme d’autres
minéraux ou matériaux industriels.
4.4 Étendue de mesure
L’expérience issue des essais d’aptitude a révélé que l’étendue de mesure de la présente partie de l’ISO 22262,
lorsqu’elle est appliquée à un échantillon préparé de manière appropriée dans lequel les fibres d’amiante
sont suffisamment grosses pour être visibles avec un microscope stéréoscopique à faible grossissement,
est comprise entre moins de 0,1 % et 100 %. La valeur inférieure de l’étendue de mesure peut être réduite en
utilisant des techniques appropriées.
4.5 Limite de détection
La limite de détection de la présente méthode est définie comme étant la détection et l’identification d’une
fibre ou d’un faisceau de fibres dans la quantité d’échantillon examinée. La limite de détection qui peut être
atteinte dépend de:
a) la nature de la matrice de l’échantillon;
b) la taille des fibres d’amiante et des faisceaux;
c) l’utilisation de procédures appropriées de préparation de l’échantillon et de réduction de la matrice;
d) le temps passé à examiner l’échantillon;
e) la méthode d’analyse utilisée — MOLP, MEB ou MET.
Avec des procédures appropriées de réduction de la matrice qui sont adaptées à la nature de l’échantillon, la
limite de détection peut être nettement inférieure à 0,01 %.
4.6 Limitations du MOLP dans la détection de l’amiante
La capacité de détection et d’identification de l’amiante par MOLP est limitée par la résolution du microscope
optique et parfois par le masquage par d’autres matériaux constituant le reste de l’échantillon. Il est peu
probable que les fibres d’amiante de largeurs inférieures à environ 0,2 µm puissent être détectées par MOLP.
Toutefois, pour toutes les variétés d’amiante amphibole et pour la plupart des variétés de chrysotile, une
grande proportion de la masse comprend des fibres dont la largeur dépasse cette valeur et, pour cette raison,
l’amiante peut être détecté de manière fiable par MOLP. En conséquence, sous réserve que la matrice du
matériau de la préparation pour le microscope soit telle qu’elle ne masque pas les éventuelles fibres d’amiante
présentes, un résultat non détecté par MOLP indique que la fraction massique d’amiante est inférieure à la
limite de détection.
Une source commerciale de chrysotile pose des problèmes de détection par MOLP. Le chrysotile provenant
de Coalinga en Californie (États-Unis) ne contient aucune fibrille de longueur supérieure à environ 30 µm; par
conséquent, si ces fibrilles sont bien dispersées dans une matrice d’échantillon, la majeure partie du chrysotile
se situe au-dessous de la taille pouvant être détectée et identifiée de manière fiable par MOLP. Le champ
d’application du chrysotile de Coalinga est limité aux dalles de planchers, aux panneaux de plafonds, aux
composés à joints pour cloisons sèches, aux mastics, aux peintures, aux matériaux d’étanchéité, aux adhésifs,
aux boues de forage, aux produits de construction moulés en ciment et aux charges minérales de certains
plastiques. Il existe une très forte probabilité pour que cette variété de chrysotile ne puisse pas être détectée par
MOLP, même si elle est présente en fractions massiques élevées. En raison de sa granulométrie, le chrysotile
de Coalinga est inadéquat pour la plupart des autres applications dans lesquelles l’amiante a été utilisé et la
probabilité qu’il puisse être rencontré dans d’autres types de produits est généralement extrêmement faible. Si,
sur la base de l’examen par MOLP, la présence de chrysotile de Coalinga est suspectée, il est recommandé
d’examiner l’échantillon par microscopie électronique.
Les fibres d’amiante ne peuvent pas être détectées par MOLP quand elles sont masquées par la matrice de
l’échantillon. Les méthodes de réduction de matrice spécifiées dans la présente partie de l’ISO 22262 sont
destinées à réduire autant que possible la possibilité de non-détection de l’amiante dans de tels échantillons.
5 Prélèvement de l’échantillon
5.1 Exigences
5.1.1 Appareil d’échantillonnage. En fonction de la nature du matériau à échantillonner, un outil approprié
est requis pour prélever l’échantillon. Si le matériau est mou, par exemple s’il s’agit d’un matériau d’isolation
thermique ou ignifuge, un couteau ou un scalpel peuvent suffire. Dans d’autres cas, un perce-bouchon peut
être utilisé pour échantillonner toutes les couches d’un matériau stratifié. Si le matériau est dur, par exemple s’il
s’agit d’amiante-ciment, des outils tels que des pinces, un coupe-fil, un marteau et un burin, ou une scie-cloche
rotative peuvent être nécessaires.
5.1.2 Aspirateur HEPA. Un aspirateur HEPA approuvé pour l’amiante est requis pour nettoyer la région autour
de l’emplacement du site d’échantillonnage après prélèvement de l’échantillon afin de réduire au minimum la
dispersion de poussières ou de particules contenant de l’amiante.
5.1.3 Matériaux et produits d’échantillonnage
5.1.3.1 Agent mouillant. Un agent mouillant peut être utilisé pour limiter la dispersion de poussière pendant
le prélèvement de l’échantillon. Avant l’échantillonnage, de l’eau, ou de l’eau mélangée avec une petite quantité
de tensioactif, peut être appliquée sur la surface à l’aide d’un pulvérisateur ou d’une brosse.
IMPORTANT — Si un échantillon est prélevé pour identifier le produit, ne pas utiliser d’agent mouillant
car ce dernier peut entraîner une altération de la composition de l’échantillon par ajout de tensioactif
et par dissolution et perte des constituants hydrosolubles.
5.1.3.2 Colmatant. Après le prélèvement de l’échantillon, une réparation mineure peut être nécessaire pour
colmater la région endommagée. Selon les cas, de la peinture à pulvériser, de la peinture de retouche ou de
l’enduit peut être utilisé.
5.1.3.3 Récipien
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