ASTM_E_1718_-_95_2004.pdf

Designation:E 1718 95(Reapproved 2004)Standard Guide forAdministrative and Engineering Controls for Silicon CarbideWhisker Work Areas1This standard is issued under the fixed designation E 1718;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide applies to workplaces where unbound siliconcarbide whiskers are manufactured,processed into products,orotherwise used.1.2 This guide offers guidance for controlling workplaceexposures to airborne silicon carbide whiskers.1.3 All applicable federal,state,county,and local regula-tions must be complied with when this guide is used.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:2E 1437 Practice for Handling Silicon Carbide WhiskersE 1451 Guide for Disposal of Wastes Containing SiliconCarbide Whiskers and FibersE 1716 Guide for the Selection and Use of Personal Protec-tive Equipment for Humans Working with RespirableSilicon Carbide WhiskersE 1717 Guide for Workplace Health and Safety Training forRespirable Silicon Carbide Whiskers3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 respirable silicon carbidea crystalline silicon car-bide material,approximately cylindrical in shape,whiskers andfibers with an aspect ratio equal to or greater than 5,and adiameter less than 3.0 m with the potential to becomeairborne.3.1.2 silicon carbide whisker work areaa hood,labora-tory,room,building,facility,or other defined area whereunbound silicon carbide whiskers are handled,and to whichpotential airborne silicon carbide whiskers can be reasonablyrestricted.3.1.3 unbound silicon carbide whiskers and fiberswhiskers and fibers with the potential to become airborne.4.Controls for Unbound Silicon Carbide Whisker WorkAreas4.1 ApplicationThe following controls should be fol-lowed for areas where unbound silicon carbide whiskers arehandled outside of closed containers,or where silicon carbidewhisker airborne concentrations are known or expected to bepresent in any quantity,regardless of duration.4.2 Administrative Controls:4.2.1 All employees associated with a silicon carbide whis-ker workplace should be trained in accordance with GuideE 1717 and Practice E 1437.4.2.2 Eating,drinking,or smoking are not permitted insilicon carbide whisker work areas.4.2.3 Shoe cleaners,tacky mats,or other type of control formaterials tracked by shoes,should be provided at appropriatelocations to prevent introduction of unbound silicon carbidewhiskers to non-work areas.4.2.4 Rotation of workers to reduce 8-h time weightedaverage exposures to silicon carbide whiskers is not recom-mended.4.3 PersonalProtectiveEquipmentConsultGuideE 1716.4.4 Engineering Controls:4.4.1 Local exhaust controls engineered for a process arepreferred.General exhaust controls are acceptable,but gener-ally less effective than local exhaust.Exhaust air from centralcollection points should be externally exhausted,filtered asappropriate to meet applicable standards.Small self-containedunits may be exhausted to the work area,if the air stream isfirst HEPA filtered before reintroduction to the work area.4.4.2 Vapor capture velocity parameters are sufficient for thedesign of exhaust controls for silicon carbide whisker workareas or points of operations.Higher design velocities may be1This guide is under the jurisdiction of ASTM Committee E34 on OccupationalHealth and Safety and is the direct responsibility of Subcommittee E34.70 on SingleCrystal Ceramic Whiskers.Current edition approved February 1,2004.Published March 2004.Originallyapproved in 1995.Last previous edition approved in 1995 as E 1718-95.2For 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.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.needed if other particulate material is a health concern ornuisance.For additional information,consult ACGIH Indus-trial VentilationA Manual of Recommended Practice.34.5 Cleaning:4.5.1 Good housekeeping should be maintained to preventaccumulations of silicon carbide whiskers.4.5.2 Compressed air shall never be used for cleaning.4.5.3 Dry sweeping with brooms shall never be used forcleaning.4.5.4 Cleaning should be done with HEPA filtered vacuumcleaners,wet sweeping methods,or equivalent methods.4.5.5 A suitable disposal container for unbound siliconcarbide whisker