ASTM E2625-09(2017)
(Practice)Standard Practice for Controlling Occupational Exposure to Respirable Crystalline Silica for Construction and Demolition Activities
Standard Practice for Controlling Occupational Exposure to Respirable Crystalline Silica for Construction and Demolition Activities
SIGNIFICANCE AND USE
3.1 These practices and criteria were developed for occupational exposures during construction and demolition activities. They are intended to (a) protect against clinically significant disease from exposure to respirable crystalline silica, (b) be measurable by techniques that are valid, reproducible, and readily available, and (c) be attainable with existing technology and protective practices.
SCOPE
1.1 This practice describes several actions to reduce the risk of harmful occupational exposures in environments containing respirable crystalline silica. This practice is intended for the unique conditions during construction and demolition activities.
1.2 Health requirements relating to occupational exposure to respirable crystalline silica not covered in this practice fall under the jurisdiction of Practice E1132.
1.3 Nothing in this practice shall be interpreted as requiring any action that violates any statute or requirement of any federal, state, or other regulatory agency.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2625 − 09 (Reapproved 2017)
Standard Practice for
Controlling Occupational Exposure to Respirable Crystalline
Silica for Construction and Demolition Activities
This standard is issued under the fixed designation E2625; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Silicondioxide(silica,SiO )isencounteredinnatureandindustryinawidevarietyofforms.These
range from essentially anhydrous types with or without a very high degree of crystallinity, to highly
hydroxylated or hydrated types which are amorphous by X-ray diffraction examination. Crystalline
silica exists in a number of forms or polymorphs. The three major forms, quartz, cristobalite, and
tridymite, pertain to this practice. Quartz (or alpha quartz) is the more common form encountered as
airborne particulates. Two of the polymorphs, cristobalite and tridymite, are formed at elevated
temperatures and are much less common in nature, but might be encountered in several occupations
where silicas are fired (calcined) at high temperatures. These silica materials have a broad range of
physical and chemical properties.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This practice describes several actions to reduce the risk
mendations issued by the World Trade Organization Technical
of harmful occupational exposures in environments containing
Barriers to Trade (TBT) Committee.
respirable crystalline silica. This practice is intended for the
unique conditions during construction and demolition activi-
2. Referenced Documents
ties.
2.1 ASTM Standards:
1.2 Health requirements relating to occupational exposure
D4532 Test Method for Respirable Dust in Workplace At-
to respirable crystalline silica not covered in this practice fall
mospheres Using Cyclone Samplers
under the jurisdiction of Practice E1132.
E1132 Practice for Health Requirements Relating to Occu-
1.3 Nothing in this practice shall be interpreted as requiring
pational Exposure to Respirable Crystalline Silica
any action that violates any statute or requirement of any
2.2 ANSI Standards:
federal, state, or other regulatory agency.
Z88.2 1992 American National Standard Practice for Respi-
ratory Protection
1.4 This standard does not purport to address all of the
ANSI/AIHAZ9.22001 FundamentalsGoverningtheDesign
safety concerns, if any, associated with its use. It is the
and Operation of Local Exhaust Systems
responsibility of the user of this standard to establish appro-
2.3 U.S. Code of Federal Regulations:
priate safety, health, and environmental practices and deter-
29 CFR 1910.134 Respiratory Protection
mine the applicability of regulatory limitations prior to use.
29 CFR 1910.1000 Air Contaminants
1.5 This international standard was developed in accor-
29 CFR 1910.1200 Hazard Communication
dance with internationally recognized principles on standard-
42 CFR 84 Title 42, Part 84 Approval of Respiratory
1 Protective Devices, Tests for Permissibility, Fees
This practice is under the jurisdiction of ASTM Committee E34 on Occupa-
tional Health and Safety and is the direct responsibility of Subcommittee E34.80 on
Industrial Heath.
Current edition approved Nov. 1, 2017. Published November 1, 2017. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 2009. Last previous edition approved in 2009 as E2625 – 09. DOI: contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
10.1520/E2625-09R17. Standards volume information, refer to the standard’s Document Summary page on
Smith, Deane K., “Opal, Cristobalite, and Tridymite: Noncrystallinity Versus the ASTM website.
Crystallinity, Nomenclature of the Silica Minerals and Bibliography,” Powder Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Diffraction, Vol 13, 1998, pp 1–18. 4th Floor, New York, NY 10036, http://www.ansi.org.
Miles, W. J., “Crystalline Silica Analysis of Wyoming Bentonite by X-ray AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
Diffraction After Phosphoric Acid Digestion,” Analytical Chemistry Acta, Vol 286, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
1994, pp 97–105. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2625 − 09 (2017)
30 CFR 56, Title 30, Subpart D Air Quality, Radiation, and 4.2.2 Where qualitative risk assessment indicates that a
Physical Agents (MSHA) potential risk is present, initial sampling of tasks or represen-
7 tative workers’ exposures shall be made to characterize the
2.4 NIOSH Publications:
exposure and its variability, to determine compliance with
Manual of Analytical Methods, 4th Ed., DHHS (NIOSH),
standards given in 4.1, and to establish a baseline exposure
Publication No. 94-113 August 1994.
level in all areas where workers are or have the potential to be
Method 7500 for Silica, Crystalline, Respirable (XRD)
exposed to silica. Initial task sampling would be not required
Method 7601 for Silica, Crystalline Visible Absorption
for short duration or transient tasks, tasks where sampling
Spectrophotometry
results would not be timely, representative concentrations are
Method 7602 for Silica, Crystalline (IR)
already known or proven task protection is in place. Conduct
2000 Guidelines for the Use of ILO International Classifi-
exposure sampling when needed to prevent a significant and
cation of Radiographs of Pneumoconioses
deleteriouschangeinthecontaminantgenerationprocessorthe
2.5 Other References:
exposure controls so that overexposures do not go undetected.
American Thoracic Society, Standardization of
This is particularly true for areas or operations where condi-
Spirometry—1994 Update
tions can change dramatically within a short span of time.
4.2.3 Recordkeeping required under this practice shall be
3. Significance and Use
maintained and made available for review by employees.
3.1 These practices and criteria were developed for occu-
4.2.4 For workers with regular exposure to high silica
pational exposures during construction and demolition activi-
concentrationswhoareplacedinsideofsuppliedairrespirators
ties. They are intended to (a) protect against clinically signifi-
or ventilated enclosures, such as in sandblasting, conduct
cant disease from exposure to respirable crystalline silica, (b)
sampling inside of the control device to determine employee
be measurable by techniques that are valid, reproducible, and
exposure. The sampling line shall not interfere with the fit of
readilyavailable,and(c)beattainablewithexistingtechnology
therespirator.Itispossiblethatconsultationwiththerespirator
and protective practices.
manufacturer will be necessary to achieve the above require-
ment.
4. General Requirements
4.2.5 In areas where overexposures are persistent, a written
4.1 Occupational Exposure Limit: exposure control plan shall be established to implement
4.1.1 Permissible Exposure Limit (PEL)—U.S. Occupa- engineering, work practice, and administrative controls to
tional Health and Safety Administration (OSHA) General reduce silica exposures to below the PEL, or other elected
Industry (see 29 CFR 1910.1000)—Workers shall not be limit, whichever is lower, to the extent feasible. Conduct a root
exposed to respirable dust containing 1 % or more quartz cause analysis for all exposures in excess of the PEL that
exceeding 10/(% quartz + 2) mg/m as an 8-h time weighted
cannot be accounted for. Root cause analysis involves investi-
average in any 8-h work shift of a 40-h work week or, for total gatingcause(s)fortheexcessiveexposure,providingremedies,
dust(respirableplusnon-respirable),30/(%quartz+2)mg/m .
and conducting follow-up sampling to document that expo-
ThePELforrespirablecristobaliteandtridymiteisone-halfthe sures are below the PEL.
value for quartz.
4.2.6 The employer shall re-assess exposures when there
3 has been a change in the process, equipment, work practices or
PEL ~mg/m !~respirablefraction! 5 10÷@% quartz1~% cristobalite
control methods that have the potential to result in new or
32 1 % tridymite 32 12
! ~ ! #
additional exposures to crystalline silica or when the employer
PEL mg/m totaldust 5 30÷ % quartz1 % cristobalite 32
~ !~ ! @ ~ !
hasanyreasontobelievethatneworadditionalexposureshave
1~% tridymite 32!12#
occurred.
4.1.2 Federal OSHA PEL is approximately equivalent to a
4.2.7 Measurement of worker occupational exposures shall
quartz level of 100µg/m .
be within the worker’s breathing zone and shall meet the
4.1.3 Employer shall determine the appropriate PEL for
criteria of this section. Such measurements need to be repre-
their operation, but in no case shall the PEL be less stringent
sentative of the worker’s customary activity and be represen-
than the applicable government limit.
tative of work shift exposure. Use area sampling to character-
ize exposures and identify effective controls when appropriate
4.2 Exposure Assessment and Monitoring:
to the circumstances.
4.2.1 Risk can be assessed qualitatively based on material
4.2.8 Respirable dust samples are to be collected in accor-
safety data sheets (MSDS), historical data, likelihood of dust
dance with accepted methods. Refer to Test Method D4532.
generation,proximityofairbornedusttoworkers,natureofthe
construction process (for example, wet work—low risk; dry 4.2.9 Sample data records shall include employee
identification, a log of the date and time of sample collection,
work—higher risk), and location of workers (for example,
sampling time duration, volumetric flow rate of sampling,
closed equipment cab). Note that the absence of visible dust is
documentation of pump calibration, and description of the
not a guarantee of lack of risk.
sampling location, analytical methods, and other pertinent
information.
4.2.10 Analyze samples for silica content analysis by an
Available from CDC/NIOSH, 4676 Columbia Pkwy, Cincinnati, OH 45226-
1998. AIHA-accredited laboratory.
E2625 − 09 (2017)
4.3 Exposure Monitoring: (2) Adequateventilationorother dust suppressionmethods
4.3.1 The employer shall provide employees with an expla- shall be provided to minimize respirable crystalline silica
nation of the sampling procedure. concentrations to below the PEL, where feasible.
4.3.2 Whenever exposure monitoring activities require en- (3) Enclosed workstations, such as control booths and
try into an area where the use of respirators, protective equipment cabs, designed for protection against respirable
clothing, or equipment is required, the employer shall provide crystalline silica dust, shall be provided with filtered air to
and ensure the use of such personal protective equipment and reduce exposures.
shall require compliance with all other applicable safety and (4) Engineering design of tools and equipment shall
health procedures. include, where feasible, provisions to minimize exposure of
4.3.3 Affected employees shall be provided with copies of workers to respirable crystalline silica dust to the PEL or
their sampling results when returned by the laboratory and below. If ventilation systems are used, they shall be designed
explanations of the data. and maintained to prevent the accumulation and re-circulation
of respirable crystalline silica dust in the working environment
4.4 Methods of Compliance:
(see ANSI Z9.2). If wet suppression systems are used, spray
4.4.1 Task-Based Control Strategies—Where exposure lev-
nozzles and associated piping shall be maintained to ensure
els are known from empirical data, a task-based control
that adequate wetting agent is applied where needed to control
strategy shall be applied that matches tasks with controls. The
respirable crystalline silica dust.
following lists examples of this approach.
(5) All engineering controls shall be properly maintained
4.4.1.1 Abrasive Blasting—OSHA has already established
and periodically evaluated and brought up to specifications,
standards for abrasive blasting work requiring ventilation (29
when needed.
CFR 1926.57) and respiratory protection (29 CFR 1926.103).
4.4.3 Work Practices and Administrative Controls:
In the case of abrasive blasting operations, it is recommended
4.4.3.1 Ensure that workers do not work in areas of visible
that the employer provide a Type CE, pressure demand or
dust generated from materials known to contain a significant
positive-pressure, abrasive blasting respirator (APF of 1000 or
percentage of respirable crystalline silica without use of
2000).
respiratoryprotection,unlessproventaskprotectionisinuseor
4.4.1.2 Otherengineeringcontrolswiththepotentialtolimit
air sampling shows exposures less than the PEL.
exposure are:
4.4.3.2 Workers shall not use compressed air to blow
(1) Using alternative materials,
respirable crystalline silica-containing materials from surfaces
(2) Wet suppression systems, and
or clothing, unless the method has been approved by an
(3) Exhaust ventilation.
appropriate regulatory agency.
4.4.1.3 Cutting Clay and Concrete Masonry Units—The
4.4.3.3 Employers shall instruct workers about specific
controls found in Tables 1-5 apply to employees cutting
work practices that minimize exposure to respirable crystalline
masonry units during a full work shift and does not apply to
silica.
occasional cutting limited to 90 min total time
4.4.3.4 Workersshallutilizegoodhousekeepingpracticesto
4.4.2 Exposure-Based Control Strategies—Where exposure
minimize the generation and accumulation of dust.
levels are measured and known to exceed the PEL, an
4.4.3.5 Workers shall utilize available means to reduce
exposure-based control strategy shall be applied that uses the
exposure to dust, including the use of respirators, rest areas,
appropriate controls to lower exposure.
ventilation systems, high efficiency particulate air (HEPA)
4.4.2.1 Engineering Controls:
vacuum cleaners or water spray, wet floor sweepers, and
(1) Use of properly designed engineering controls is the
rotation of personnel to minimize individual exposure.
most desirable approach for controlling dust from crystalline
silica-containing materials. 4.5 Respiratory Protection:
TABLE 1 Cutting Masonry Units
Operation/Task Control Measures Respiratory Protection
Cutting masonry units— Wet Method: Continuously apply stream or Not Required
(Using stationary or portable saws) spray at the cutting point.
OR 100 series filtering face piece
Dry M
...
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 version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: E2625 − 09 E2625 − 09 (Reapproved 2017)
Standard Practice for
Controlling Occupational Exposure to Respirable Crystalline
Silica for Construction and Demolition Activities
This standard is issued under the fixed designation E2625; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Silicon dioxide (silica, SiO ) is encountered in nature and industry in a wide variety of forms. These
range from essentially anhydrous types with or without a very high degree of crystallinity, to highly
hydroxylated or hydrated types which are amorphous by X-ray diffraction examination. Crystalline
silica exists in a number of forms or polymorphs. The three major forms, quartz, cristobalite, and
tridymite, pertain to this practice. Quartz (or alpha quartz) is the more common form encountered as
airborne particulates. Two of the polymorphs, cristobalite and tridymite, are formed at elevated
temperatures and are much less common in nature, but might be encountered in several occupations
where silicas are fired (calcined) at high temperatures. These silica materials have a broad range of
physical and chemical properties.
1. Scope
1.1 This practice describes several actions to reduce the risk of harmful occupational exposures in environments containing
respirable crystalline silica. This practice is intended for the unique conditions during construction and demolition activities.
1.2 Health requirements relating to occupational exposure to respirable crystalline silica not covered in this practice fall under
the jurisdiction of Practice E1132.
1.3 Nothing in this practice shall be interpreted as requiring any action that violates any statute or requirement of any federal,
state, or other regulatory agency.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D4532 Test Method for Respirable Dust in Workplace Atmospheres Using Cyclone Samplers
E1132 Practice for Health Requirements Relating to Occupational Exposure to Respirable Crystalline Silica
2.2 ANSI Standards:
Z88.2 1992 American National Standard Practice for Respiratory Protection
ANSI/AIHA Z9.2 2001 Fundamentals Governing the Design and Operation of Local Exhaust Systems
This practice is under the jurisdiction of ASTM Committee E34 on Occupational Health and Safety and is the direct responsibility of Subcommittee E34.80 on Industrial
Heath.
Current edition approved May 1, 2009Nov. 1, 2017. Published May 2009November 1, 2017. Originally approved in 2009. Last previous edition approved in 2009 as
E2625 – 09. DOI: 10.1520/E2625-09.10.1520/E2625-09R17.
Smith, Deane K., Opal,“Opal, Cristobalite, and Tridymite: Noncrystallinity Versus Crystallinity, Nomenclature of the Silica Minerals and Bibliography cristobalite, and
tridymite: Noncrystallinity versus crystallinity, nomenclature of the silica minerals and bibliography, ,” Powder Diffraction, Vol 13, 1998, pp 1–18.
Miles, W.J., Crystalline silicaW. J., “Crystalline Silica Analysis of Wyoming Bentonite by X-ray Diffraction After Phosphoric Acid Digestion analysis of Wyoming
bentonite by X-ray diffraction after phosphoric acid digestion, ,” Analytical Chemistry Acta, Vol 286, 1994, pp 97–105.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2625 − 09 (2017)
2.3 U.S. Code of Federal Regulations:
29 CFR 1910.134 Respiratory Protection
29 CFR 1910.1000 Air Contaminants
29 CFR 1910.1200 Hazard Communication
42 CFR 84 Title 42, Part 84 Approval of Respiratory Protective Devices, Tests for Permissibility, Fees
30 CFR 56, Title 30, Subpart D Air Quality, Radiation, and Physical Agents (MSHA)
2.4 NIOSH Publications:
Manual of Analytical Methods, 4th Ed., DHHS (NIOSH), Publication No. 94-113 August 1994.
Method 7500 for Silica, Crystalline, Respirable (XRD)
Method 7601 for Silica, Crystalline Visible Absorption Spectrophotometry
Method 7602 for Silica, Crystalline (IR)
2000 Guidelines for the Use of ILO International Classification of Radiographs of Pneumoconioses
2.5 Other References:
American Thoracic Society, Standardization of Spirometry—1994 Update
3. Significance and Use
3.1 These practices and criteria were developed for occupational exposures during construction and demolition activities. They
are intended to (a) protect against clinically significant disease from exposure to respirable crystalline silica, (b) be measurable by
techniques that are valid, reproducible, and readily available, and (c) be attainable with existing technology and protective
practices.
4. General Requirements
4.1 Occupational Exposure Limit:
4.1.1 Permissible Exposure Limit (PEL)—U.S. Occupational Health and Safety Administration (OSHA) General Industry (see
29 CFR 1910.1000)—Workers shall not be exposed to respirable dust containing 1 % or more quartz exceeding 10/(% quartz +
2) mg/m as an 8-h time weighted average in any 8-h work shift of a 40-h work week or, for total dust (respirable plus
non-respirable), 30/(% quartz + 2) mg/m . The PEL for respirable cristobalite and tridymite is one-half the value for quartz.
PEL ~mg/m ! ~respirable fraction! 5 10÷@% quartz1~% cristobalite 32!1~% tridymite 32!12#
PEL ~mg/m ! ~total dust! 5 30÷@% quartz1~% cristobalite 32!1~% tridymite 32!12#
4.1.2 Federal OSHA PEL is approximately equivalent to a quartz level of 100μg/m .
4.1.3 Employer shall determine the appropriate PEL for their operation, but in no case shall the PEL be less stringent than the
applicable government limit.
4.2 Exposure Assessment and Monitoring:
4.2.1 Risk can be assessed qualitatively based on material safety data sheets (MSDS), historical data, likelihood of dust
generation, proximity of airborne dust to workers, nature of the construction process (for example, wet work—low risk; dry
work—higher risk), and location of workers (for example, closed equipment cab). Note that the absence of visible dust is not a
guarantee of lack of risk.
4.2.2 Where 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, to determine compliance with standards given
in 4.1, and to establish a baseline exposure level in all areas where workers are or have the potential to be exposed to silica. Initial
task sampling would be not required for short duration or transient tasks, tasks where sampling results would not be timely,
representative concentrations are already known or proven task protection is in place. Conduct exposure sampling when needed
to prevent a significant and deleterious change in the contaminant generation process or the exposure controls so that
overexposures do not go undetected. This is particularly true for areas or operations where conditions can change dramatically
within a short span of time.
4.2.3 Recordkeeping required under this practice shall be maintained and made available for review by employees.
4.2.4 For workers with regular exposure to high silica concentrations who are placed inside of supplied air respirators or
ventilated enclosures, such as in sandblasting, conduct sampling inside of the control device to determine employee exposure. The
sampling line shall not interfere with the fit of the respirator. It is possible that consultation with the respirator manufacturer will
be necessary to achieve the above requirement.
4.2.5 In areas where overexposures are persistent, a written exposure control plan shall be established to implement engineering,
work practice, and administrative controls to reduce silica exposures to below the PEL, or other elected limit, whichever is lower,
to the extent feasible. Conduct a root cause analysis for all exposures in excess of the PEL that cannot be accounted for. Root cause
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.
Available from CDC/NIOSH, 4676 Columbia Pkwy, Cincinnati, OH 45226-1998.
E2625 − 09 (2017)
analysis involves investigating cause(s) for the excessive exposure, providing remedies, and conducting follow-up sampling to
document that exposures are below the PEL.
4.2.6 The employer shall re-assess exposures when there has been a change in the process, equipment, work practices or control
methods that have the potential to result in new or additional exposures to crystalline silica or when the employer has any reason
to believe that new or additional exposures have occurred.
4.2.7 Measurement of worker occupational exposures shall be within the worker’s breathing zone and shall meet the criteria of
this section. Such measurements need to be representative of the worker’s customary activity and be representative of work shift
exposure. Use area sampling to characterize exposures and identify effective controls when appropriate to the circumstances.
4.2.8 Respirable dust samples are to be collected in accordance with accepted methods. Refer to Test Method D4532.
4.2.9 Sample data records shall include employee identification, a log of the date and time of sample collection, sampling time
duration, volumetric flow rate of sampling, documentation of pump calibration, and description of the sampling location, analytical
methods, and other pertinent information.
4.2.10 Analyze samples for silica content analysis by an AIHA-accredited laboratory.
4.3 Exposure Monitoring:
4.3.1 The employer shall provide employees with an explanation of the sampling procedure.
4.3.2 Whenever exposure monitoring activities require entry into an area where the use of respirators, protective clothing, or
equipment is required, the employer shall provide and ensure the use of such personal protective equipment and shall require
compliance with all other applicable safety and health procedures.
4.3.3 Affected employees shall be provided with copies of their sampling results when returned by the laboratory and
explanations of the data.
4.4 Methods of Compliance:
4.4.1 Task-basedTask-Based Control Strategies—Where exposure levels are known from empirical data, a task based task-based
control strategy shall be applied that matches tasks with controls. The following lists examples of this approach.
4.4.1.1 Abrasive Blasting—OSHA has already established standards for abrasive blasting work requiring ventilation (29
C.F.R.CFR 1926.57) and respiratory protection (29 C.F.R.CFR 1926.103). In the case of abrasive blasting operations, it is
recommended that the employer provide a Type CE, pressure demand or positive-pressure, abrasive blasting respirator (APF of
1000 or 2000).
4.4.1.2 Other engineering controls with the potential to limit exposure are:
(1) Using alternative materials,
(2) Wet suppression systemssystems, and
(3) Exhaust ventilationventilation.
4.4.1.3 Cutting Clay and Concrete Masonry Units—The controls found in Tables 1-5 apply to employees cutting masonry units
during a full work shift and does not apply to occasional cutting limited to 90 minutesmin total time
4.4.2 Exposure-basedExposure-Based Control Strategies—Where exposure levels are measured and known to exceed the PEL,
an exposure based exposure-based control strategy shall be applied that uses the appropriate controls to lower exposure.
4.4.2.1 Engineering Controls:
(1) Use of properly designed engineering controls is the most desirable approach for controlling dust from crystalline
silica-containing materials.
(2) Adequate ventilation or other dust suppression methods shall be provided to minimize respirable crystalline silica
concentrations to below the PEL, where feasible.
(3) Enclosed workstations, such as control booths and equipment cabs, designed for protection against respirable crystalline
silica dust, shall be provided with filtered air to reduce exposures.
TABLE 1 Cutting Masonry Units
Operation/Task Control Measures Respiratory Protection
Cutting masonry units— Wet Method: Continuously apply stream or Not Required
(Using stationary or portable saws) spray at the cutting point.
OR 100 series filtering face piece
Dry Method: Enclose saw within a (disposable dust mask)
ventilated enclosure operated with a OR
minimum face velocity of 250 feet-per-minute. ⁄2 face
Saw blade must be contained entirely respirator with 100 series filters
within the booth and exhaust must be
directed away from other workers
or fed to a dust collector with a HEPA
filtration system.
* Additional control measures for consideration:
Ventilation (natural and mechanical), dust collection
methods, architectural design, use special-shaped
products, job rotation and demarcation of specific
cutting areas.
E2625 − 09 (2017)
TABLE 2 Mixing Concrete, Grout, and Mortar
Operation/Task Control Measures Respiratory Protection
Mixing Concrete, Grout or Mortar Natural ventilation and demarcation of mixing areas Not Required
TABLE 3 Tuck Pointing
NOTE 1—The following control measures have the potential to be useful in reducing exposure levels, but are not necessarily adequate to reliably reduce
exposures below the PEL.
Operation/Task Control Measures Respiratory Protectio
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.