1、Designation: E1132 06E1132 13Standard Practice forHealth Requirements Relating to Occupational Exposure toRespirable Crystalline Silica1This standard is issued under the fixed designation E1132; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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.INTRODUCTIONSilicon dioxide (silica, SiO2) is encountered in nature and industry in a wide variety of form
3、s. Theserange from essentially anhydrous types with or without a very high degree of crystallinity, to highlyhydroxylated or hydrated types which are amorphous by x-ray diffraction examination. Crystallinesilica2 exists in a number of forms or polymorphs. The three major forms, quartz, cristobalite,
4、 andtridymite, pertain to this practice. Quartz (or alpha quartz) is the more common form encountered asairborne particulates. Two of the polymorphs, cristobalite and tridymite, are formed at elevatedtemperatures and are much less common in nature, but might be encountered in several occupationswher
5、e silicas are fired (calcined) at high temperatures.3 These silica materials have a broad range ofphysical and chemical properties.1. Scope1.1 This practice covers a description of several actions that should be taken to reduce the risk of harmful occupationalexposures to humans in environments cont
6、aining respirable crystalline silica. This practice is intended for, but not limited to,industries regulated by the U.S. Mine Safety and Health Administration (MSHA) and the U.S. Occupational Safety and HealthAdministration (OSHA).Aseparate practice, designed for the unique conditions of the constru
7、ction industry is under development.Whilehas been designated Practice E2625this practice was not designed specifically for construction, it can be applied and maybe beneficial, to the extent feasible and practical, pending adoption of a construction industry standard1.2 Nothing in this practice shal
8、l be interpreted as requiring any action that violates any statute or requirement of any federal,state, or other regulatory agency.1.3 UnitsThe values stated in SI units are to be regarded as the standard. No other units of measurement are included in thisstandard.1.4 This standard does not purport
9、to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. It is the responsibility of the user to consult all
10、 material safety data sheets and labels pertaining to anyhazardous materials used in this standard.2. Referenced Documents2.1 ASTM Standards:4D4532 Test Method for Respirable Dust in Workplace Atmospheres Using Cyclone SamplersE2625 Practice for Controlling Occupational Exposure to Respirable Crysta
11、lline Silica for Construction and DemolitionActivities1 This practice is under the jurisdiction of ASTM Committee E34 on Occupational Health and Safetyand is the direct responsibility of Subcommittee E34.16 on Silicas.Current edition approved Dec. 1, 2006July 1, 2013. Published January 2007July 2013
12、. Originally approved in 1999. Last previous edition approved in 19992006 asE1132 - 99a.E1132 - 06. DOI: 10.1520/E1132-06.10.1520/E1132-13.2 Smith, Deane K., Opal, cristobalite, and tridymite: Noncrystallinity versus crystallinity, nomenclature of the silica minerals and bibliography, Powder Diffrac
13、tion, Vol13, 1998, pp. 118.3 Miles, W. J., Crystalline silica analysis of Wyoming bentonite by X-ray diffraction after phosphoric acid digestion, Analytical Chemistry Acta, Vol 286, 1994, pp. 97105.4 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service a
14、t serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous ver
15、sion. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM Internatio
16、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 ANSI Standards:5ANSI/AIHA Z9.2 Fundamentals Governing the Design and Operation of Local Exhaust SystemsANSI Z9.7Z88.2 American National Standard Practice for Respiratory Protection2.3 Code of Federal Regulat
17、ions:629 CFR 1910.94, Ventilation29 CFR 1910.134, Respiratory Protection29 CFR 1910.1000, Air Contaminants29 CFR 1910.1200, Hazard Communication29 CFR 1926.57 Ventilation29 CFR 1926.103 Respiratory Protection30 CFR 47, Hazard Communication30 CFR 56, Title 30, Subpart D, Air Quality, Radiation, and P
18、hysical Agents (MSHA)42 CFR 84 Title 42, Part 84, Approval of Respiratory Protective Devices, Tests for Permissibility, Fees2.4 NIOSH Publications:7Manual of Analytical Methods, 4th Ed., DHHS (NIOSH), Publication No. 94-113, August 1994Method 7500 for Silica, Crystalline, Respirable (XRD)Method 7601
19、 for Silica, Crystalline Visible Absorption SpectrophotometryMethod 7602 for Silica, Crystalline (IR)Method 7603 for Coal Mine Dust by IR2000 Guidelines for the Use of the ILO International Classification of Radiographs of Pneumoconioses2.5 Other References:National Industrial Sand Association, Occu
20、pational Health Program for Exposure to Crystalline Silica in the Industrial SandIndustry, March 1997American Thoracic Society, Standardization of Spirometry3. Significance and Use3.1 These practices and criteria were developed for occupational exposures. They are intended to (a) protect against cli
21、nicaldisease from exposure to respirable crystalline silica, (b) be measurable by techniques that are valid, reproducible, and readilyavailable, and (c) be attainable with existing technology and protective practices.4. General Requirements4.1 Occupational Exposure Limits (OEL):4.1.1 Permissible Exp
22、osure Limit (PEL) established by U.S. Occupational Health and Safety Administration (OSHA) GeneralIndustry (see 29 CFR 1910.1000)Workers shall not be exposed to respirable dust containing 1 % or more quartz exceeding10/(% quartz + 2) mg/m3 as an 8-h time weighted average in any 8-h work shift of a 4
23、0-h work week or, for total dust (respirableplus non-respirable), 30/(% quartz + 2) mg/m3. The PEL for respirable cristobalite and tridymite is one-half the value for quartz.4.1.1.1 PEL (mg/m3) (respirable fraction):10%quartz1%cristobalite32!1%tridymite32!12#4.1.1.2 PEL (mg/m3) (total dust):30%quart
24、z1%cristobalite32!1%tridymite32!12#NOTE 1Federal OSHA PEL is approximately equivalent to a quartz level of 100 g/m3.4.1.2 PEL established by U.S. Mine Safety and Health Administration (MSHA) (non-coal) (see 30 CFR 56.5001)Workersshall not be exposed to respirable dust containing 1 % or more quartz e
25、xceeding the PEL as determined for a time weighted 8-hworkday and 40-h workweek based on the following formula: PEL= 10/(% quartz + 2) mg/m3. The PELfor respirable cristobaliteand tridymite is one-half the value for quartz.4.1.3 Occupational Exposure Limits may vary country by country. Please consul
26、t the authority in the country, where theoperation exists. Examples of other OELs are provided in Appendix X2.4.1.4 Employers shall determine the appropriate OEL for their operation, but in no case shall the OEL be less stringent than theapplicable government limit.4.2 Exposure Assessment and Monito
27、ring:5 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.6 Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.7
28、 Available from National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering, 4676 Columbia Parkway, Cincinnati, OH 45226.E1132 1324.2.1 Risk can be assessed qualitatively based on Material Safety Data Sheets (MSDS),(SDS), prior information, likelihood ofdust
29、generation, proximity of airborne dust to workers, nature of the industrial process (example: wet worklow risk; dryworkhigher risk), and location of workers (example: control room). Note that the absence of visible dust is not a guarantee oflack of risk.4.2.2 Initial sampling of representative worke
30、rsWhere qualitative risk assessment indicates that a potential risk is present,initial sampling of tasks or representative workers exposures shall be made to characterize the exposure and its variability, todetermine compliance with standards given in 4.1, and to establish a baseline exposure level
31、in all areas where workers are or mayhave the potential to be exposed to silica. Initial task sampling would be not required for short duration or transient tasks, taskswhere timely sampling results would not be available,timely, representative concentrations are already known, and provenknownor pro
32、ved task protection is in place. Exposure sampling should be periodic, and should occur frequently enough that a Conductexposure sampling when needed to detect overexposures due to significant and deleterious change in the contaminant generationprocess or the exposure controls is not permitted to go
33、 undetected. controls. This is particularly true for areas or operations whereconditions can change dramatically within a short span of time.4.2.3 When sampling is conducted, workers with a high relative risk of dust exposure should be sampled first. Sampling shouldthen progress toward those individ
34、uals with low exposure risk. High relative risk can be assigned to any area where the processinvolved may generate respirable crystalline silica particles and persons are potentially exposed for most or all of a workshift.Sampling strategy should follow good industrial hygiene practice.4.2.4 Employe
35、rs shall sample occupational exposures of workers exposed to respirable crystalline silica and maintain recordsof such sampling.Recordkeeping required under this practice shall be maintained and made available for review by employees andconsistent with federal or state requirements.4.2.5 For workers
36、 with regular exposure to high silica concentrations that are placed inside of supplied air respirators orventilated enclosures, such as in sandblasting, sampling should be conducted inside of the control device to determine employeeexposure. The sampling line shall not interfere with the fit of the
37、 respirator. Consultation with the respirator manufacturer may benecessary to achieve the above requirement.4.2.6 In areas where overexposures are persistent, a written Exposure Control Plan shall be established to implementengineering, work practice, and administrative controls to reduce silica exp
38、osures to below the OEL, or other elected limit,whichever is lower, to the extent feasible. A root cause analysis should be conducted for all exposures in excess of the OEL thatcannot be accounted for. Root cause analysis involves investigating cause(s) for the excessive exposure, providing remedies
39、, andconducting follow-up sampling to document that exposures are below the OEL.4.2.7 Sampling shall be done at a frequency that provides reliable information for determining an appropriate control strategy.Sampling information and recommended frequency is summarized in Table 1.4.2.8 Because people
40、have different work habits, sampling should be rotated among different employees performing the sametask with a goal of sampling each individual at least once every three years or use statistical random sampling.4.2.9 Measurement of worker occupational exposures shall be within the workers breathing
41、 zone and shall meet the criteria ofthis section. Such measurements should be representative of the workers customary activity and should be representative ofworkshift exposure. Area sampling may be used to characterize exposures and identify effective controls when appropriate to thecircumstances.4
42、.2.10 Respirable dust samples are to be collected according to accepted methods. Refer to Test Method D4532 and seeAppendix X1 for an example.4.2.11 Sampling data records shall include employee identification, a log of the date and time of sample collection, samplingtime duration, volumetric flow ra
43、te of sampling, documentation of pump calibration, description of the sampling location,analytical methods, and other pertinent information. See Figs. X1.1-X1.3 for example sampling record, calibration forms, andemployee notification of dust sampling results.4.2.12 Samples for silica analysis should
44、 be analyzed by an AIHA-accredited laboratory.4.3 Observation of Exposure Monitoring:4.3.1 Employee ObservationThe employer shall provide affected employees or their designated representatives an opportunityto observe any monitoring of employee exposure to silica and provide an employees with an exp
45、lanation of the samplingprocedure.4.3.2 Monitoring ProceduresWhenever observation of the monitoring of employee exposure to respirable crystalline silicarequires exposure monitoring activities require entry into an area where the use of respirators, protective clothing, or equipmentis required, the
46、employer shall provide and ensure the use of such personal protective equipment and shall require compliance withall other applicable safety and health procedures.4.3.3 Monitoring ResultsObservers shall be entitled to:Sampled employees shall be provided with copies of their samplingresults when retu
47、rned by the laboratory and explanations of their data.4.3.3.1 Receive an explanation of the measurement and analytical procedures,4.3.3.2 Observe all steps related to the monitoring of respirable crystalline silica performed at the place of exposure, andE1132 133TABLE 1 Sampling InformationCondition
48、 ActionQualitative assessment Based on evaluation of process andmaterials used and visual review ofdust generation potential.Initial sampling Conducted at representative jobfunctions starting with assumed highestdust exposure levels.Results used to establishsampling plan.Initial sampling Conducted a
49、t representative jobfunctions starting with assumed highestdust exposure levels or based onrepresentative sampling data fordefined tasks. Results used to establishsampling or protection plan, or both.Sampling results are below one halfthe OELNo periodic sampling necessary butadditional samples may be required dueto process changes.Sampling results are belowOELNo periodic sampling necessary butadditional samples may be required dueto process changes or new qualitativeassessments.No OEL overexposures were found,but exposures exceed one half theOELThese note
