1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 13794:1999 ICS 13.
2、040.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Ambient air Determination of asbestos fibres Indirect-transfer transmission electron microscopy methodThis British Standard, having been prepared under the direction of the Health and Environment Sector Committee was publi
3、shed under the authority of the Standards Committee and comes into effect 15 November 1999 BSI 11-1999 ISBN 0 580 32865 1 BS ISO 13794:1999 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard reproduces verbatim ISO 13794:1999 and implements it as the U
4、K national standard. The UK participation in its preparation was entrusted by Technical Committee EH/2, Air quality, to Subcommittee EH/2/3, Ambient atmospheres, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enq
5、uiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The
6、 British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A B
7、ritish Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a f
8、ront cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 64, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when this document was last issued.A Referencenumbe r ISO13794:1999(E) LANOITANRETNI DRADNATS OSI 49
9、731 noitidetsriF 51709991 AmbientairDeterminationofasbestos fibresIndirecttransfertransmission electronmicroscopymethod AirambiantDosagedesfibresdamianteMthodeparmicroscopie lectroniquetransmissionpartransfertindirect A ebmunecnerefeR r )E(9991:49731OSI LANOITANRETNI DRADNATS OSI 49731 Firstedition
10、19990715 sotsebsafonoitanimreteDriatneibmA noissimsnartrefsnarttceridnIserbif dohtemypocsorcimnortcele eipocsorcimrapedohtMetnaimadserbifsedegasoDtnaibmariA tceridnitrefsnartrapnoissimsnarteuqinortcel A ebmunecnerefeR r )E(9991:49731OSI INTERNATIONAL STANDARD ISO 13794 Firstedition 19990715 sotsebsa
11、fonoitanimreteDriatneibmA noissimsnartrefsnarttceridnIserbif dohtemypocsorcimnortcele eipocsorcimrapedohtMetnaimadserbifsedegasoDtnaibmariA tceridnitrefsnartrapnoissimsnarteuqinortcel A Referencenumbe r )E(9991:49731OSI LANOITANRETNI STANDARD OSI 13794 noitidetsriF 51709991 AmbientairDeterminationof
12、asbestos fibresIndirecttransfertransmission electronmicroscopymethod AirambiantDosagedesfibresdamianteMthodeparmicroscopie lectroniquetransmissionpartransfertindirect BS ISO 13794:1999)E(9991:49731OSI OSI9991 rllAightsreserved.Unelssotherwisespeceifid,noparotfhtsipubcilatoinamybereproducedorutzilied
13、nianyofrmorbyan ymsnae,lecetrinoc .rehsilbupehtmorfgnitirwninoissimreptuohtiw,mliforcimdnagniypocotohpgnidulcni,lacinahcemro noitazidradnatSrofnoitazinagrOlanoitanretnI 65elatsopesaC 02evneG1121HC dnalreztiwS tenretnI hc.osiosi dnalreztiwSnidetnirP ii Contents Page 1Scope 1 1.1Substancedetermined .
14、1 1.2Typeofsample. .1 1.3Range .1 1.4Limitofdetection. .1 2Termsanddefinitions .2 3Abbreviatedterms .6 4Principle 6 5Apparatus .7 5.1Airsampling . .7 5.2Specimenpreparationlaboratory .8 5.3Equipmentforanalysis . .8 5.4Consumablesupplies .13 6Reagents. 14 7Airsamplecollection .14 7.1Calculationofanal
15、yticalsensitivity 14 7.2Samplecollectionprocedure .15 8Procedureforanalysis . .15 8.1General .15 8.2Cleaningofsamplecassettes . 16 8.3Preparationofanalyticalfilters .16 8.4PreparationofTEMspecimensfromPCanalyticalfilters 17 BS ISO 13794:1999OSI )E(9991:49731OSI iii 8.5PreparationofTEMspecimensfromce
16、lluloseesteranalyticalfilters. . 19 8.6CriteriaforacceptableTEMspecimengrids. . 20 8.7ProcedureforstructurecountingbyTEM . 21 8.8Blankandqualitycontroldeterminations. . 24 8.9Calculationofresults . 25 9Performancecharacteristics 25 9.1General 25 9.2Interferencesandlimitationsoffibreidentification 25
17、 9.3Precisionandaccuracy. . 26 9.4Limitofdetection. . 26 10Testreport . . 27 AnnexA (normative) Determinationofoperatingconditionsforplasmaasher. 30 AnnexB (normative) Determinationandstandardizationofoperatingconditionsforultrasonicbath 31 AnnexC (normative) Calibrationprocedures 3 3 AnnexD (normat
18、ive) Structurecountingcriteria 36 AnnexE (normative) Fibreidentificationprocedure . 44 AnnexF (normative) Determinationofconcentrationsofasbestosfibresandbundleslongerthan5 mm, andofPCMequivalentasbestosfibres . 53 AnnexG (normative) Calculationofresults . 54 AnnexH (normative) Testproceduretodeterm
19、inesuitabilityofcelluloseestersamplecollectionfilters. 60 AnnexI (informative) Strategiesforcollectionofairsamples . 61 Bibliography 62 BS ISO 13794:1999)E(9991:49731OSI OSI iv Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodie
20、s).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in liaisonwithISO,alsotake
21、partinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtot
22、hememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. InternationalStandardISO13794waspreparedbyTechnicalCommitteeISO/TC146, Airquality,Subcommittee SC3, Ambientatmospheres . AnnexesAtoHformanormativepartofthisInternationalStandard.An
23、nexIisforinformationonly. BS ISO 13794:1999OSI )E(9991:49731OSI v Introduction ThisInternationalStandardisapplicabletothemeasurementofairborneasbestosinawiderangeofambientair situations,includingtheinterioratmospheresofbuildings,andfordetailedevaluationofanyatmosphereinwhich asbestosfibresarelikelyt
24、obepresent.Becausethebestavailablemedicalevidenceindicatesthatthenumerical fibreconcentrationandthefibresizeandtypearetherelevantparametersforevaluationoftheinhalationhazards, afibrecountingandmeasuringtechniqueistheonlylogicalapproach.Mostfibresinambientatmospheresarenot asbestos,andthereforetherei
25、sarequirementforfibrestobeidentified.Manyairborneasbestosfibresinambient atmosphereshavediametersbelowtheresolutionlimitoftheopticalmicroscope.ThisInternationalStandardis basedontransmissionelectronmicroscopy,whichhasadequateresolutiontoallowdetectionofsmallfibresandis currentlytheonlytechniquecapab
26、leofunequivocalidentificationofthemajorityofindividualfibresofasbestos.The fibresfoundsuspendedinanambientatmospherecanoftenbeidentifiedunequivocally,ifsufficientmeasurement effortisexpended.However,ifeachfibreweretobeidentifiedinthisway,theanalysisbecomesprohibitively expensive.Becauseofinstrumenta
27、ldeficienciesorbecauseofthenatureoftheparticulate,somefibrescannotbe positivelyidentifiedasasbestos,eventhoughthemeasurementsallindicatethattheycouldbeasbestos.Subjective andinstrumentalfactorsthereforecontributetothismeasurement,andconsequentlyaveryprecisedefinitionofthe procedureforidentificationa
28、ndenumerationofasbestosfibresisrequired. Inadditiontosinglefibresandbundles,asbestosisoftenfoundinairsamplesasverycomplex,aggregated structureswhichmayormaynotbealsoaggregatedwithotherparticles.Thenumberofasbestosfibresand bundlesincorporatedinthesecomplexstructuresoftenexceedsthenumberofisolatedfib
29、resandbundles observed,andmanyofthemmaybecompletelyobscuredindirecttransferTEMpreparations.Themethoddefined inthisInternationalStandardincorporatesspecimenpreparationproceduresthatresultinselectiveconcentrationof asbestosfibres,andremovaloforganicandwatersolublematerials.Theseprocedureshavetheeffect
30、of dispersingthemajorityofthecomplexclustersandaggregatesoffibresintotheircomponentfibresandbundlesso thattheasbestosintheairsamplecanbemoreaccuratelyquantified.Allofthefeasiblespecimenpreparation techniquesresultinsomemodificationoftheairborneparticulate.Eventhecollectionofparticlesfroma threedimen
31、sionalairbornedispersionontoatwodimensionalfiltersurfacecanbeconsideredamodificationofthe particulate,andsomeoftheparticlesinmostsamplesaremodifiedbythespecimenpreparationprocedures. Althoughthismethodresultsindispersalofcomplexclustersandaggregates,itminimizesothereffectsonthesize distributionoffib
32、resandfibrebundles. ThisInternationalStandardisnecessarilycomplex,becausetheinstrumentaltechniquesusedarecomplex,and alsobecauseaverydetailedandlogicalproceduremustbespecifiedtoreducethesubjectiveaspectsofthe measurement.ThemethodofdatarecordingspecifiedinthisInternationalStandardisdesignedtoallow r
33、eevaluationofthefibrecountingdataasnewmedicalevidencebecomesavailable. ThisInternationalStandarddescribesthemethodofanalysisforasingleairfilter.However,oneofthelargest potentialerrorsincharacterizingasbestosinambientatmospheresisassociatedwiththevariabilitybetweenfilter samples.Forthisreason,itisnec
34、essarytodesignareplicatesamplingschemeinordertodeterminethestandards accuracyandprecision. Comparisonofresultsobtainedusingthisindirecttransferprocedurewiththosefromthedirecttransferprocedure maynotbedone apriori. Asitespecificintercomparisonstudymustbedonewhichtakesintoaccountthefibresize andtypeof
35、asbestos,andalsothenatureofthesourceoftheairborneasbestos. BS ISO 13794:1999BS ISO 13794:1999DRADNATSLANOITANRETNI OSI )E(9991:49731OSI 1 AmbientairDeterminationofasbestosfibresIndirect transfertransmissionelectronmicroscopymethod 1Scope 1.1Substance determined ThisInternationalStandardspecifiesaref
36、erencemethodusingtransmissionelectronmicroscopy(TEM)for determinationoftheconcentrationofasbestosstructuresinambientatmospheres.Thespecimenpreparation procedureincorporatesashinganddispersionofthecollectedparticulate,sothatallasbestosismeasured, includingtheasbestosoriginallyincorporatedinparticleag
37、gregatesorparticlesofcompositematerials.Thelengths, widthsandaspectratiosoftheasbestosfibresandbundlesaremeasured,andthese,togetherwiththedensityof thetypeofasbestos,alsoallowthetotalmassconcentrationofairborneasbestostobecalculated.Themethod allowsdeterminationofthetype(s)ofasbestosfibrepresent.The
38、methodcannotdiscriminatebetweenindividual fibresoftheasbestosandnonasbestosanaloguesofthesameamphibolemineral. 1.2 Typeofsample Themethodisdefinedforpolycarbonatecapillaryporefiltersorcelluloseester(eithermixedestersofcelluloseor cellulosenitrate)filtersthroughwhichaknownvolumeofairhasbeendrawn.Them
39、ethodissuitablefor determinationofasbestosinbothexteriorandbuildingatmospheres. 1.3Range Theupperlimitfortherangeofconcentrationthatcanbemeasuredontheanalyticalfilteris7000structures/mm 2 . Thelowerlimitoftherangethatcanbemeasuredontheanalyticalfiltercorrespondstodetectionof2,99structures intheareao
40、fspecimenexamined.Theairconcentrationsrepresentedbythesevaluesareafunctionofthevolume ofairsampledandthedegreeofdilutionorconcentrationselectedduringthespecimenpreparationprocedures. Themethodisparticularlyapplicableformeasurementsinareaswithhighsuspendedparticulateconcentrations (exceeding10g/m 3 )
41、,orwheredetectionandidentificationofasbestosfibresarelikelytobepreventedorhindered byothertypesofparticulateindirecttransferTEMpreparations.Intheory,thereisnolowerlimittothedimensions ofasbestosfibreswhichcanbedetected.Inpractice,microscopistsvaryintheirabilitytodetectverysmall asbestosfibres.Theref
42、ore,aminimumlengthof0,5mhasbeendefinedastheshortestfibretobeincorporatedin thereportedresults. 1.4 Limitofdetection Thelimitofdetectiontheoreticallycanbeloweredindefinitelybyfiltrationofprogressivelylargervolumesofair, concentratingthesampleduringspecimenpreparation,andbyextendingtheexaminationofthe
43、specimensinthe electronmicroscope.Inpractice,thelowestachievablelimitofdetectionforaparticularareaofTEMspecimen examinediscontrolledbythetotalsuspendedparticulateconcentrationremainingaftertheashingandaqueous dispersalsteps,andthisdependsonthechemicalnatureofthesuspendedparticulate.Fortotalsuspended
44、 particulateconcentrationsofapproximately10g/m 3 ,correspondingtoclean,ruralatmospheres,andassuming filtrationof4000litresofair,ananalyticalsensitivityof0,5structure/litrecanbeobtained,equivalenttoalimitof detectionof1,8structures/litre,ifanareaof0,195mm 2 oftheTEMspecimensisexamined.Lowerlimitsof detectioncanbeachievedbyincreasingtheareaoftheTEMspecimenthatisexamined,orbyconcentrationofthe sampleduringspecimenpreparation.I
