ASTM_D_6058_-_96_2011.pdf

Designation:D605896(Reapproved 2011)Standard Practice forDetermining Concentration of Airborne Single-CrystalCeramic Whiskers in the Workplace Environment1This standard is issued under the fixed designation D6058;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is intended to assist individuals in thesampling and analysis of single-crystal ceramic whiskers(SCCW),such as silicon carbide and silicon nitride,in theworkplace environment.It describes sampling and analyticaltechniques used to assess the airborne concentration and sizedistribution of SCCW,which may occur in and around theworkplace where these materials are manufactured,processed,transported,or used.1.2 The protocols currently in use for asbestos and otherfibrous materials have been used as a guide in developingsampling and analytical procedures for characterizing fibersproduced from the manufacture and use of SCCW.Thesampling and analysis protocols described here have beenwritten specifically for SCCW,however,they may be appro-priate for other man-made mineral fibers(MMMF).1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 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 practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD6056 Test Method for Determining Concentration of Air-borne Single-Crystal Ceramic Whiskers in the WorkplaceEnvironment by Transmission Electron MicroscopyD6057 Test Method for Determining Concentration of Air-borne Single-Crystal Ceramic Whiskers in the WorkplaceEnvironment by Phase Contrast MicroscopyD6059 Test Method for Determining Concentration of Air-borne Single-Crystal Ceramic Whiskers in the WorkplaceEnvironment by Scanning Electron Microscopy3.Terminology3.1 For definitions of terms used in this practice,refer toTerminology D1356.3.2 Definitions:3.2.1 man-made mineral fiber,nany inorganic fibrousmaterial produced by chemical or physical processes.3.2.2 single-crystal ceramic whisker,na man-made min-eral fiber that has a single-crystal structure.3.2.2.1 DiscussionAlthough the terms fiber and whiskerare,for convenience,used interchangeably in this practice,whisker is correctly applied only to single-crystal fiberswhereas a fiber may be single-or poly-crystalline or may benoncrystalline.4.Summary of Practice4.1 This practice is based on a three-tier approach to thequantitative assessment of airborne SCCW levels.It includesdetailed procedures to analyze standard air sampling cassettesby phase contrast microscopy(PCM),scanning electron mi-croscopy(SEM),and transmission electron microscopy(TEM).4.2 The choice of a particular analytical method shall bebased on the visibility limitation of each instrument and anunderstanding of the actual size distribution of the fibers beinganalyzed.4.3 In general,PCM is suitable for the analysis of fibers thatare greater than approximately 0.25 m in diameter.Dependingon the instrument and the sample preparation method used,theSEM may be capable of examining fibers as small as 0.10 min diameter.TEM has been shown to be suitable for the studyof even finer fibers.The high resolution of this instrumentmakes it well suited for the determination of the fraction of afiber population with diameters#0.10 to 0.25 m.1This practice is under the jurisdiction ofASTM Committee 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 1996.Last previous edition approved in 2006 as D6058-96(2006).DOI:10.1520/D6058-96R11.2For referenced 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.4 In addition to an enhanced image resolution,SEM andTEM have the further advantage of providing elementalcomposition information on a single fiber.Furthermore,TEMmay also be used to ascertain crystallographic data on the fiber.This additional information is frequently helpful in the analysisof samples which contain numerous unknown fibers and,thus,SEM or TEM,or both,are preferred in such instances.5.Significance and Use5.1 The SCCW may be present in the workplace atmospherewherethesematerialsaremanufactured,process