1、Designation: D7521 16Standard Test Method forDetermination of Asbestos in Soil1This standard is issued under the fixed designation D7521; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parent
2、heses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure to: (1) identifyasbestos in soil, (2) provide an estimate of the concentration ofasbestos in the sampled soil (drie
3、d), and (3) optionally toprovide a concentration of asbestos reported as the number ofasbestos structures per gram of sample.1.2 In this test method, results are produced that may beused for evaluation of sites contaminated by construction, mineand manufacturing wastes, deposits of natural occurrenc
4、es ofasbestos (NOA), and other sources of interest to the investiga-tor.1.3 This test method describes the gravimetric, sieve, andother laboratory procedures for preparing the soil for analysisas well as the identification and quantification of any asbestosdetected. Pieces of collected soil and mate
5、rial embeddedtherein that pass through a 19-mm sieve will become part of thesample that is analyzed and for which results are reported.1.3.1 Asbestos is identified and quantified by polarized lightmicroscopy (PLM) techniques including analysis of morphol-ogy and optical properties. Optional transmis
6、sion electronmicroscopy (TEM) identification and quantification of asbestosis based on morphology, selected area electron diffraction(SAED), and energy dispersive X-ray analysis (EDXA). Someinformation about fiber size may also be determined. The PLMand TEM methods use different definitions and size
7、 criteria forfibers and structures. Separate data sets may be produced.1.4 This test method has an analytical sensitivity of 0.25 %by weight with optional procedures to allow for an analyticalsensitivity of 0.1 % by weight.1.5 This test method does not purport to address samplingstrategies or variab
8、les associated with soil environments. Suchconsiderations are the responsibility of the investigator collect-ing and submitting the sample. Appendix X2 covering ele-ments of soil sampling and good field practices is attached.1.6 UnitsThe values stated in SI units are to be regardedas the standard. O
9、ther units may be cited in the method forinformational purposes only.1.7 HazardsAsbestos fibers are acknowledged carcino-gens. Breathing asbestos fibers can result in disease of thelungs including asbestosis, lung cancer, and mesothelioma.Precautions should be taken to avoid creating and breathingai
10、rborne asbestos particles when sampling and analyzingmaterials suspected of containing asbestos.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health p
11、ractices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C136 Test Method for Sieve Analysis of Fine and CoarseAggregatesD1193 Specification for Reagent WaterD3670 Guide for Determination of Precision and Bias ofMethods of Committee
12、D22D6281 Test Method for Airborne Asbestos Concentration inAmbient and Indoor Atmospheres as Determined byTransmission Electron Microscopy Direct Transfer (TEM)D6620 Practice for Asbestos Detection Limit Based onCountsE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE177 Practice for
13、Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 EPA Standards:3EPA 600/R-93/116 Method for the Determination of Asbes-tos in Bulk Building Materials1This test method is under the jurisdiction o
14、f ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.07 on Sampling andAnalysis of Asbestos.Current edition approved May 1, 2016. Published May 2016. Originallyapproved in 2013. Last previous edition approved in 2013 as D7521 13. DOI:10.1520/D7521-16.2For reference
15、d ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from United States Environmental Protection Agency (EPA), ArielR
16、ios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20004, http:/www.epa.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.3 ISO Standards:4ISO 10312:1995 Ambient Air -Determination of AsbestosFibersDirect Transfer Transmission
17、Electron MicroscopyMethod (1st Ed. 1995-05-01)ISO 17025 General requirements for the competence oftesting and calibration laboratoriesISO/DIS 22262-1 Bulk materialsPart 1: Sampling andqualitative determination of asbestos in commercial bulkmaterials3. Terminology3.1 Definitions:3.1.1 asbestiform, nt
18、ype of fibrous habit in which thefibers are separable into thinner fibers and ultimately intofibrils.3.1.1.1 DiscussionThis habit accounts for greater flexibil-ity and higher tensile strength than other habits of the samemineral. For more information on asbestiform mineralogy, seeSteel and Wylie5and
19、 Zussman.63.1.2 asbestos, na collective term that describes a groupof naturally occurring, inorganic, highly-fibrous, silicate min-erals that are easily separated into long, thin, flexible, strongfibers when crushed or processed.3.1.2.1 DiscussionIncluded in the definition are the as-bestiform varie
20、ties of serpentine (chrysotile); riebeckite (cro-cidolite); grunerite (grunerite asbestos Amosite); anthophyl-lite (anthophyllite asbestos); tremolite (tremolite asbestos); andactinolite (actinolite asbestos). The amphibole mineral compo-sitions are defined according to the nomenclature of theIntern
21、ational Mineralogical Association.3.1.2.2 DiscussionThe mineral fibers described in thisdefinition are listed below. This method is also applicable toother mineral fibers of interest not listed in Table 1.3.1.3 aspect ratio, nratio of the length of a fibrous particleto its average width.3.1.4 bundle
22、, nstructure composed of two or more fibersin a parallel arrangement with the fibers closer than one fiberdiameter to each other.3.1.5 cluster, nstructure with fibers in a random arrange-ment such that all fibers are intermixed and no single fiber isisolated from the group; groupings of fibers shall
23、 have morethan two points touching.3.1.6 fiber (transmission electron microscopy, TEM),nstructure having a minimum length of 0.5 um, an aspectratio of 5:1 or greater, and substantially parallel sides.3.1.7 fibril, nsingle fiber that cannot be separated intosmaller components without losing its fibro
24、us properties orappearance.3.1.8 fibrous (polarized light microscopy, PLM), adjmineral composed of parallel, radiating, or interlaced aggre-gates of fibers from which the fibers may or may not beseparable, that is, the crystalline aggregate may be referred toas fibrous even if it is not composed of
25、separable fibers but hasthat distinct appearance.3.1.8.1 DiscussionThe term fibrous is used in a generalmineralogical way to describe aggregates of grains that crys-tallize in a needle-like habit and appear to be composed offibers. The term fibrous has a much more general meaning thanasbestos. While
26、 it is correct that all asbestos minerals can havea fibrous habit, not all minerals having fibrous habits areasbestos.3.1.9 free fibers, nduring sample collection, these arefibers that are not associated with discrete pieces of buildingmaterial or debris in the soil.3.1.9.1 DiscussionFree fibers may
27、 or may not be visible tothe unaided eye. Their source (for example, weatheredasbestos-cement products) may or may not be present in thesoil in an amount sufficient to collect a bulk sample, if at all.3.1.10 matrix, nstructure in which one or more fibers, orfiber bundles that are touching, are attac
28、hed to or partiallyconcealed by a single particle or connected group of nonfibrousparticles.3.1.10.1 DiscussionThe exposed fiber shall meet the fiberdefinition (see fiber (TEM).3.1.11 point count, nquantitative regimen with definitionsthat can be found under EPA 600 R-93/116. A technique usedto dete
29、rmine the relative projected areas occupied by separatecomponents in a microscope slide preparation of a sample. Forasbestos analysis, this technique is used to determine therelative concentrations of asbestos minerals to non-asbestossample components.3.1.12 soil, nfor this test method, soil is cons
30、ideredmaterial of variable particle size and composition generallyless than 19 mm in size.3.1.12.1 DiscussionExamples may include loosely con-solidated sediments, building materials, and other accumulatedmaterials at the surface. Other materials larger than 19 mm mayalso be submitted at the collecto
31、rs discretion as separate bulksamples.3.1.13 structures (TEM), nterm that is used to categorizeall the types of asbestos particles which are recorded during theanalysis (such as fibers, bundles, clusters, and matrices).3.1.14 visual area estimate, VAE, nquantitative estimateof the amount of asbestos
32、 present most readily obtained byvisual comparison of the bulk sample and slide preparations toother slide preparations and bulk samples with known amountsof asbestos present in them.3.1.14.1 DiscussionGiven that soils are typically4Available from American National Standards Institute (ANSI), 25 W.
33、43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Steel, E., and A. Wylie, “Mineralogical Characteristics of Asbestos,” inGeology of Asbestos Deposits, P. H. Riordon, Ed., SME-AIME, 1981, pp. 93101.6Zussman, J., “The Mineralogy of Asbestos,” in Asbestos: Properties, Applica-tions and Hazar
34、ds, John Wiley and Sons, 1979, pp. 4567.TABLE 1 AsbestosAsbestos Chemical Abstract Service No.Chrysotile 12001-29-5Crocidolite 12001-28-4Amosite 12172-73-5Anthophyllite asbestos 77536-67-5Tremolite asbestos 77536-68-6Actinolite asbestos 77536-66-4Asbestos 1332-21-4D7521 162heterogeneous, sieving the
35、 soil helps to achieve similar particlesize and facilitates subsequent VAE on the three sievedfractions.3.2 Descriptions for TEM Analysis Using Test MethodD6281:3.2.1 asbestos fiber or bundle longer than 5 m, nanyasbestos fiber or any width, bundle, or such fibers that has alength exceeding 5 m.3.2.
36、2 asbestos structure larger than 5 m, nany fiber,bundle, cluster, or matrix for which the largest dimensionexceeds 5 m; does not necessarily contain asbestos fibers orbundles longer than 5 m.3.2.3 compact matrix (Type C), nstructure consisting of aparticle or linked group of particles in which fiber
37、s or bundlescan be seen either within the structure or projecting from it,such that the dimensions of individual fibers and bundlescannot be unambiguously determined.3.2.4 disperse matrix (Type D), nstructure consisting of aparticle or linked group of particles with overlapping orattached fibers or
38、bundles in which at least one of theindividual fibers or bundles can be separately identified and itsdimensions measured.3.2.4.1 DiscussionIn practice, matrices can occur inwhich the characteristics of both types of matrix occur in thesame structure. When this occurs, the structure should beassigned
39、 as a disperse matrix, and then a logical procedureshould be followed by recording structure components accord-ing to the counting criteria.3.2.5 fibers that extend outside the field of view, nduringscanning of a grid opening, count fibers that extend outside thefield of view systematically so as to
40、 avoid double counting.3.2.5.1 DiscussionIn general, a rule should be establishedso that fibers extending outside the field of view in only twoquadrants are counted. Measure the length of each of thesefibers by moving the specimen to locate the other end of thefiber and then return to the original f
41、ield of view beforecontinuing to scan the specimen. Fibers without terminationswithin the field of view shall not be counted.3.2.6 other-structure-counting criteria, nTest MethodD6281 structure-counting criteria may be used for TEM andPCM equivalent analysis of structures in the fine fraction.3.2.7
42、phase contrast microscope (PCM) equivalent fiber,nany particle with parallel or stepped sides with an aspectratio of 3:1 or greater, longer than 5 m that has a diameterbetween 0.2 and 3.0 m (according to Test Method D6281).3.2.7.1 DiscussionFor chrysotile, PCM-equivalent fiberswill always be bundles
43、.3.2.8 PCM-equivalent structure, nany fiber, bundle,cluster, or matrix with an aspect ratio of 3:1 or greater, longerthan 5 m, that has a diameter between 0.2 and 3.0 m.3.2.8.1 DiscussionPCM-equivalent structures do not nec-essarily contain fibers or bundles longer than 5 m or PCM-equivalent fibers.
44、3.2.8.2 DiscussionRecord the dimensions of the structuresuch that the obscured portions of components are taken to beequivalent to the unobscured portions. For example, the lengthof a fiber intersecting a grid bar is taken to be twice theunobscured length. Structures intersecting either of the other
45、two sides shall not be included in the count.4. Summary of Test Method4.1 The sample is dried and sieved with sieves arrangedfrom top to bottom: 19 mm, 2 mm, 106 m, and collection pan.The sieve fractions are designated coarse fraction (2mm), medium fraction (106 m), and fine fraction(19-mm fraction
46、may be ana-lyzed using stereomicroscopy and polarized light microscopy(PLM) and reported separately but are not considered part ofthis method. The results are not included in the final result ofthe other three sieves fractions. Any building material debriscollected from the field along with the soil
47、 sample may also beanalyzed and reported separately. The coarse, medium, and finefractions are all analyzed by stereomicroscopy and PLM visualarea estimation (VAE). Initial results for the PLM analyses areexpressed in calibrated visual area estimated percent andresults for the fine fraction using po
48、int count values if belowdetection limit (see also 11.4.2-11.4.4). In addition, if PLMresults indicate none detected, then the fine fraction of thesample may be analyzed for asbestos using transmissionelectron microscopy (TEM) drop mount as outlined in 11.6.1.If the TEM drop mount is negative or a q
49、uantitative result isdesired, then it is recommended that the sample be gravimetri-cally reduced and visually estimated by TEM to derive aquantitative result expressed as an estimated weight percent.4.2 Optional TEM Analysis by Test Method D6281Additional analysis of the fine fraction may be performed toprovide size data and concentration of asbestos reported as thenumber of asbestos structures per gram of sample.4.3 The nominal quantity of soil sieved and analyzed is a250-cm3sample.Alarger amount (no more than 500 cm3) may
