1、Designation:D720106(Reapproved 2011)Standard Practice forSampling and Counting Airborne Fibers,Including AsbestosFibers,in the Workplace,by Phase Contrast Microscopy(with an Option of Transmission Electron Microscopy)1This standard is issued under the fixed designation D7201;the number immediately f
2、ollowing the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice2descri
3、bes the determination of the con-centration of fibers,expressed as the number of such fibers permillilitre of air,using phase contrast microscopy and optionallytransmission electron microscopy to evaluate particulate mate-rial collected on a membrane filter in the breathing zone of anindividual or b
4、y area sampling in a specific location.Thispractice is based on the core procedures provided in theInternational Organization for Standardization(ISO)StandardISO 8672(1)3,the National Institute for Occupational andHealth(NIOSH)Manual of Analytical Methods,NIOSH 7400(2),and the Occupational Safety an
5、d Health Administration(OSHA)Method ID 160(3).This practice indicates the impor-tant points where these methods differ,and provides informa-tion regarding the differences,which will allow the user toselect the most appropriate procedure for a particular applica-tion.However,selecting portions of pro
6、cedures from differentpublished methods generally requires a user to report that theyhave used a modification to a method rather than claim theyhave used the method as written.1.2 The practice is used for routine determination of anindex of occupational exposure to airborne fibers in work-places.Wor
7、kplaces are considered those places where workersare exposed to airborne fibers including asbestos.Additionalinformation on sampling strategies,sample collection(includ-ing calibration)and use of sample results for asbestos abate-ment projects is provided in a standard Practice for AirMonitoring for
8、 Management of Asbestos-Containing Materials(WK 8951)currently being considered by ASTM subcommit-tee E06.24.A further practice has been approved for thespecific purpose of sampling and counting airborne fibers inmines and quarries(Practice D7200),although the practiceherein may also be used for thi
9、s purpose.The current practicemay be used as a means of monitoring occupational exposureto asbestos fibers when asbestos fibers are known a priori to bepresent in the airborne dust.The practice gives an index ofairborne fiber concentration.This practice may be used inconjunction with electron micros
10、copy(See Appendix X1)forassistance in identification of fibers.This practice may be usedfor other materials such as fibrous glass,or man-made mineralfibers by using alternate counting rules(see Annex A4).1.3 This practice specifies the equipment and procedures forsampling the atmosphere in the breat
11、hing zone of an individualand for determining the number of fibers accumulated on afilter membrane during the course of an appropriately-selectedsampling period.The practice may also be used to sample theatmosphere in a specific location or room of a building(areasampling),where this may be helpful
12、in assessing exposure toworkers handling fiber-containing products.1.4 The ideal working range of this test practice extendsfrom 100 fibers/mm2to 1300 fibers/mm2of filter area.For a1000-L air sample,this corresponds to a concentration rangefrom approximately 0.04 to 0.5 fiber/mL(or fiber/cm3).Lowera
13、nd higher ranges of fiber concentration can be measured byreducing or increasing the volume of air collected.However,when this practice is applied to sampling the presence of other,non-asbestos dust,the level of total suspended particulate mayimpose an upper limit to the volume of air that can be sa
14、mpledif the filters produced are to be of appropriate fiber loading forfiber counting.1.5 Users should determine their own limit of detectionusing the procedure in Practice D6620.For Reference theNIOSH 7400 method gives the limit of detection as 7 fibers/mm2of filter area.For a 1000 L air sample,thi
15、s corresponds toa limit of detection of 0.0027 fiber/mL(or fiber/cm3).ForOSHA method ID 160 the limit of detection is given as 5.5fibers/mm2of filter area.For a 1000 L air sample,thiscorresponds to a limit of detection of 0.0022 fiber/mL(orfiber/cm3).1This practice is under the jurisdiction ofASTM C
16、ommittee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 2006.Last previous edition approved in 2006 as D7201 06.DOI:10.1520/D7201-06R11.2This test method is based on NIOSH 7400,OSHA Method ID 160,and ISO8672.Users of this ASTM standard are cautioned that if they wish to comply withone of these specific procedures exactly they should follow that procedure,otherwise
