ASTM E2625-19

Standard Practice for Controlling Occupational Exposure to Respirable Crystalline Silica for Construction and Demolition Activities

SIGNIFICANCE AND USE
4.1 These practices and criteria were developed for occupational exposures during construction and demolition activities. They are intended to (1) protect against clinically significant disease from exposure to respirable crystalline silica, (2) be measurable by techniques that are valid, reproducible, and readily available, and (3) 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

• Status: Published
• Publication Date: 14-Aug-2019
• ICS: 13.040.30 - Workplace atmospheres
• Technical Committee: E34 - Occupational Health and Safety
• Drafting Committee: E34.80 - Industrial Health

Relations

• Replaces: ASTM E2625-09(2017) - Standard Practice for Controlling Occupational Exposure to Respirable Crystalline Silica for Construction and Demolition Activities
• Effective Date: 15-Aug-2019
• Refers: ASTM E1542-20 - Standard Terminology Relating to Occupational Health and Safety
• Effective Date: 01-Jan-2020
• Refers: ASTM E1542-18 - Standard Terminology Relating to Occupational Health and Safety
• Effective Date: 01-Feb-2018
• Refers: ASTM E1132-13 - Standard Practice for Health Requirements Relating to Occupational Exposure to Respirable Crystalline Silica
• Effective Date: 01-Jul-2013
• Refers: ASTM E1542-10 - Standard Terminology Relating to Occupational Health and Safety
• Effective Date: 01-Aug-2010
• Refers: ASTM D4532-10 - Standard Test Method for Respirable Dust in Workplace Atmospheres Using Cyclone Samplers
• Effective Date: 01-Apr-2010
• Refers: ASTM E1132-06 - Standard Practice for Health Requirements Relating to Occupational Exposure to Respirable Crystalline Silica
• Effective Date: 01-Dec-2006
• Refers: ASTM E1542-93(2004) - Standard Terminology Relating to Occupational Health and Safety
• Effective Date: 01-Apr-2004
• Refers: ASTM D4532-97(2003) - Standard Test Method for Respirable Dust in Workplace Atmospheres
• Effective Date: 10-Apr-2003
• Refers: ASTM E1132-99a - Standard Practice for Health Requirements Relating to Occupational Exposure to Respirable Crystalline Silica
• Effective Date: 10-Aug-1999
• Refers: ASTM E1542-93(1998) - Standard Terminology Relating to Occupational Health and Safety
• Effective Date: 01-Jan-1998
• Refers: ASTM D4532-97 - Standard Test Method for Respirable Dust in Workplace Atmospheres
• Effective Date: 10-Dec-1997
• Referred By: ASTM E1132-21 - Standard Practice for Health Requirements Relating to Occupational Exposure to Respirable Crystalline Silica
• Effective Date: 15-Aug-2019

Overview

ASTM E2625-19 is the Standard Practice for Controlling Occupational Exposure to Respirable Crystalline Silica for Construction and Demolition Activities, developed by ASTM International. This standard provides comprehensive guidelines to reduce the risk of harmful occupational exposures to respirable crystalline silica - a prevalent airborne hazard in construction and demolition environments. The aim is to minimize clinically significant diseases linked to silica dust, using practical, measurable, and achievable control methods and practices available within current technological capabilities.

Exposure to respirable crystalline silica can result in severe health effects, such as silicosis, lung cancer, and other respiratory diseases, making control strategies essential for workplace safety.

Key Topics

• Scope and Purpose

  • Targets construction and demolition settings with potential for respirable crystalline silica exposure.
  • Intended to protect worker health, ensure compliance, and align with government regulations and international best practices.
  • Complements other standards, such as ASTM E1132, for broader health requirements.

• Exposure Limits and Assessment

  • Emphasizes adherence to national permissible exposure limits (PELs), including those set by OSHA.
  • Requires qualitative and quantitative exposure assessments, sampling, and documentation using valid and reproducible methods.
  • Mandates re-assessment if processes, controls, or conditions change.

• Control Measures

  • Engineering Controls: Includes local exhaust ventilation, wet suppression methods, and dust collection systems to capture or suppress airborne silica.
  • Work Practice Controls: Training, housekeeping, proper positioning, job rotation, and safe methods for handling silica-containing materials.
  • Personal Protective Equipment (PPE): Use of respirators and protective clothing when engineering and administrative controls are insufficient.

• Medical Surveillance and Protection

  • Periodic medical exams (e.g., chest X-rays, spirometry, tuberculosis testing) for workers with significant exposure.
  • Establishes programs for respiratory protection, worker education, and counseling for individuals with identified health risks.

• Training and Documentation

  • Requires comprehensive worker training on silica hazards, exposure controls, PPE, and safe work practices.
  • Employers must maintain accessible records of exposure monitoring, medical evaluations, and training completion.

Applications

ASTM E2625-19 is widely applicable to various construction and demolition activities where worker exposure to respirable crystalline silica is a concern, such as:

• Cutting, drilling, or sawing concrete and masonry materials
• Abrasive blasting and tuck pointing
• Mixing concrete, mortar, or grout
• Hand and power tool operations on silica-containing materials
• Demolition of structures containing quartz, cristobalite, or tridymite

Adhering to this standard helps employers implement robust silica dust controls, including both task-based (specific control measures for certain activities) and exposure-based (general engineering and administrative strategies) approaches. It facilitates compliance with regulatory requirements, reduces health risks, and supports a safer work environment for employees.

Related Standards

Organizations implementing ASTM E2625-19 should be familiar with related documents for a complete silica management program:

• ASTM E1132: Practice for Health Requirements Relating to Occupational Exposure to Respirable Crystalline Silica
• ASTM D4532: Test Method for Respirable Dust in Workplace Atmospheres Using Cyclone Samplers
• ASTM E1542: Terminology Relating to Occupational Health and Safety
• ANSI Z88.2: Practices for Respiratory Protection
• ANSI/AIHA Z9.2: Fundamentals Governing the Design and Operation of Local Exhaust Systems
• NIOSH Methods: 7500 (XRD), 7601, 7602 for silica analysis
• U.S. OSHA Standards: 29 CFR 1910.134 (Respiratory Protection), 29 CFR 1910.1000 (Air Contaminants), 29 CFR 1910.1200 (Hazard Communication)

For more information or to access the official standard, visit the ASTM International website or consult the relevant regulatory agencies.

Keywords: crystalline silica, respirable silica dust, occupational exposure, construction safety, demolition, exposure control, air monitoring, silica standard, PPE, engineering controls, worker training, health surveillance.

Standards Content (Sample)

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.
Designation: E2625 − 19
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 E1542 Terminology Relating to Occupational Health and
federal, state, or other regulatory agency.
Safety
2.2 ANSI Standards:
1.4 This standard does not purport to address all of the
Z88.2 1992 American National Standard Practice for Respi-
safety concerns, if any, associated with its use. It is the
ratory Protection
responsibility of the user of this standard to establish appro-
ANSI/AIHAZ9.22001 FundamentalsGoverningtheDesign
priate safety, health, and environmental practices and deter-
and Operation of Local Exhaust Systems
mine the applicability of regulatory limitations prior to use.
2.3 U.S. Code of Federal Regulations:
1.5 This international standard was developed in accor-
29 CFR 1910.134 Respiratory Protection
dance with internationally recognized principles on standard-
29 CFR 1910.1000 Air Contaminants
1 29 CFR 1910.1200 Hazard Communication
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 Aug. 15, 2019. Published August 2019. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 2009. Last previous edition approved in 2017 as E2625 – 09 (2017). contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
DOI: 10.1520/E2625-19. 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 − 19
42 CFR 84 Title 42, Part 84 Approval of Respiratory construction process (for example, wet work—low risk; dry
Protective Devices, Tests for Permissibility, Fees work—higher risk), and location of workers (for example,
30 CFR 56, Title 30, Subpart D Air Quality, Radiation, and closed equipment cab). Note that the absence of visible dust is
Physical Agents (MSHA) not a guarantee of lack of risk.
2.4 NIOSH Publications:
5.2.2 Where qualitative risk assessment indicates that a
Manual of Analytical Methods, 4th Ed., DHHS (NIOSH),
potential risk is present, initial sampling of tasks or represen-
Publication No. 94-113 August 1994.
tative workers’ exposures shall be made to characterize the
Method 7500 for Silica, Crystalline, Respirable (XRD)
exposure and its variability, to determine compliance with
Method 7601 for Silica, Crystalline Visible Absorption
standards given in 5.1, and to establish a baseline exposure
Spectrophotometry
level in all areas where workers are or have the potential to be
Method 7602 for Silica, Crystalline (IR)
exposed to silica. Initial task sampling would be not required
2000 Guidelines for the Use of ILO International Classifi-
for short duration or transient tasks, tasks where sampling
cation of Radiographs of Pneumoconioses
results would not be timely, representative concentrations are
2.5 Other References:
already known, or proven task protection is in place. Conduct
American Thoracic Society, Standardization of
exposure sampling when needed to prevent a significant and
Spirometry—1994 Update
deleteriouschangeinthecontaminantgenerationprocessorthe
exposure controls so that overexposures do not go undetected.
3. Terminology
This is particularly true for areas or operations where condi-
3.1 For definitions not in this standard related to this
tions can change dramatically within a short span of time.
practice, refer to Terminology E1542.
5.2.3 Recordkeeping required under this practice shall be
maintained and made available for review by employees.
4. Significance and Use
5.2.4 For workers with regular exposure to high silica
4.1 These practices and criteria were developed for occu-
concentrationswhoareplacedinsideofsupplied-airrespirators
pational exposures during construction and demolition activi-
or ventilated enclosures, such as in sandblasting, conduct
ties. They are intended to (1) protect against clinically signifi-
sampling inside of the control device to determine employee
cant disease from exposure to respirable crystalline silica, (2)
exposure. The sampling line shall not interfere with the fit of
be measurable by techniques that are valid, reproducible, and
the respirator. It is possible that consultation with the respirator
readily available, and (3) be attainable with existing technol-
manufacturer will be necessary to achieve the above require-
ogy and protective practices.
ment.
5. General Requirements
5.2.5 In areas where overexposures are persistent, a written
exposure control plan shall be established to implement
5.1 Occupational Exposure Limit:
engineering, work practice, and administrative controls to
5.1.1 Permissible Exposure Limit (PEL)—U.S. Occupa-
reduce silica exposures to below the PEL, or other elected
tional Health and Safety Administration (OSHA) General
limit, whichever is lower, to the extent feasible. Conduct a root
Industry (see 29 CFR 1910.1000)—Workers shall not be
cause analysis for all exposures in excess of the PEL that
exposed to respirable dust containing 1 % or more quartz
cannot be accounted for. Root cause analysis involves investi-
exceeding 10/(% quartz + 2) mg/m as an 8-h time-weighted
gatingcause(s)fortheexcessiveexposure,providingremedies,
average in any 8-h work shift of a 40-h work week or, for total
and conducting follow-up sampling to document that expo-
dust (respirable plus non-respirable), 30/(% quartz + 2) mg/m .
sures are below the PEL.
ThePELforrespirablecristobaliteandtridymiteisone-halfthe
value for quartz.
5.2.6 The employer shall re-assess exposures when there
3 hasbeenachangeintheprocess,equipment,workpractices,or
PEL ~mg/m !~total dust! 5 30÷@% quartz1~% cristobalite 32!
control methods that have the potential to result in new or
1 % tridymite 32 12
~ ! #
additionalexposurestocrystallinesilica,orwhentheemployer
PEL mg/m respirable fraction 5 10÷@% quartz1 % cristobalite
~ !~ ! ~
hasanyreasontobelievethatneworadditionalexposureshave
32!1~% tridymite 32!12#
occurred.
5.1.2 Federal OSHA PEL is approximately equivalent to a
5.2.7 Measurement of worker occupational exposures shall
quartz level of 100 µg⁄m .
be within the worker’s breathing zone and shall meet the
5.1.3 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
5.2 Exposure Assessment and Monitoring:
to the circumstances.
5.2.1 Risk can be assessed qualitatively based on material
safety data sheets (MSDS), historical data, likelihood of dust 5.2.8 Respirable dust samples are to be collected in accor-
generation,proximityofairbornedusttoworkers,natureofthe dance with accepted methods. Refer to Test Method D4532.
5.2.9 Sample data records shall include employee
identification, a log of the date and time of sample collection,
Available from CDC/NIOSH, 4676 Columbia Pkwy, Cincinnati, OH 45226-
1998. sampling time duration, volumetric flow rate of sampling,
E2625 − 19
documentation of pump calibration, and description of the 5.4.2.1 Engineering Controls:
sampling location, analytical methods, and other pertinent (1) Use of properly designed engineering controls is the
information. most desirable approach for controlling dust from crystalline
5.2.10 Analyze samples for silica content analysis by an silica-containing materials.
AIHA-accredited laboratory. (2) Adequate ventilation or other dust suppression methods
shall be provided to minimize respirable crystalline silica
5.3 Exposure Monitoring:
concentrations to below the PEL, where feasible.
5.3.1 The employer shall provide employees with an expla-
(3) Enclosed workstations, such as control booths and
nation of the sampling procedure.
equipment cabs designed for protection against respirable
5.3.2 Whenever exposure monitoring activities require en-
crystalline silica dust, shall be provided with filtered air to
try into an area where the use of respirators, protective
reduce exposures.
clothing, or equipment is required, the employer shall provide
(4) Engineering design of tools and equipment shall
and ensure the use of such personal protective equipment and
include, where feasible, provisions to minimize exposure of
shall require compliance with all other applicable safety and
workers to respirable crystalline silica dust to the PEL or
health procedures.
below. If ventilation systems are used, they shall be designed
5.3.3 Affected employees shall be provided with copies of
and maintained to prevent the accumulation and re-circulation
their sampling results when returned by the laboratory and
of respirable crystalline silica dust in the working environment
explanations of the data.
(see ANSI Z9.2). If wet suppression systems are used, spray
5.4 Methods of Compliance:
nozzles and associated piping shall be maintained to ensure
5.4.1 Task-Based Control Strategies—Where exposure lev-
that adequate wetting agent is applied where needed to control
els are known from empirical data, a task-based control
respirable crystalline silica dust.
strategy shall be applied that matches tasks with controls. The
(5) All engineering controls shall be properly maintained
following lists examples of this approach.
and periodically evaluated and brought up to specifications,
5.4.1.1 Abrasive Blasting—OSHA has already established
when needed.
standards for abrasive blasting work requiring ventilation (29
5.4.3 Work Practices and Administrative Controls:
CFR 1926.57) and respiratory protection (29 CFR 1926.103).
5.4.3.1 Ensure that workers do not work in areas of visible
In the case of abrasive blasting operations, it is recommended
dust generated from materials known to contain a significant
that the employer provide a Type CE, pressure demand or
percentage of respirable crystalline silica without use of
positive-pressure, abrasive blasting respirator (APF of 1000 or
respiratoryprotection,unlessproventaskprotectionisinuseor
2000).
air sampling shows exposures less than the PEL.
5.4.1.2 Otherengineeringcontrolswiththepotentialtolimit
5.4.3.2 Workers shall not use compressed air to blow
exposure are:
respirable crystalline silica-containing materials from surfaces
(1) Using alternative materials,
or clothing, unless the method has been approved by an
(2) Wet suppression systems, and
appropriate regulatory agency.
(3) Exhaust ventilation.
5.4.3.3 Employers shall instruct workers about specific
5.4.1.3 Cutting Clay and Concrete Masonry Units—The
work practices that minimize exposure to respirable crystalline
controls found in Tables 1-5 apply to employees cutting
silica.
masonry units during a full work shift and do not apply to
5.4.3.4 Workersshallutilizegoodhousekeepingpracticesto
occasional cutting limited to 90 min total time
minimize the generation and accumulation of dust.
5.4.2 Exposure-Based Control Strategies—Where exposure
levels are measured and known to exceed the PEL, an 5.4.3.5 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)
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 − 19
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
NOTE1—Thefollowingcontrolmeasureshavethepotentialtobeusefulinreducingexposurelevels,butarenotnecessarilyadequatetoreliablyreduce
exposures below the PEL.
Operation/Task Control Measures Respiratory Protection
Tuck Pointing The following control measures may be useful in reducing exposure These types of respiratory protection will be necessary to
levels but may not be adequate to reliably reduce exposures below provide adequate protection in the absence of control meth-
the PEL. ods that demonstrate compliance with the PEL:
Ventilation Full-face respirator with 100 series filter
Natural OR
Mechanical Supplied-air respirator
Dust collection/vacuum
Shroud
Gauge/Guide for Equipment
Wet methods
TABLE 4 Concrete Cutting
Operation/Task Control Measures Respiratory Protection
Outdoor Slab Sawing Use water-fed system that delivers water continuously at the cut Not Required
point with natural ventilation OR Early entry sawing OR Dry
cutting with integrated vacuum system
Indoor Slab Sawing Use water-fed system that delivers water continuously at the cut 100 series filtering face piece respirator
point with natural ventilation.
OR 100 series filtering face piece respirator
Mechanical ventilation (fans)
OR 100 series filtering face piece respirator
Early entry sawing
OR
Dry cutting with integrated vacuum system
Outdoor Wire Sawing w/ remote Use water-fed system that delivers water continuously on wire, Not Required
Outdoor Wire Sawing w/o remote operated via remote control with natural ventilation.
Outdoor Wall Sawing Use water-fed system that delivers water continuously on blade Not Required
with natural ventilation.
Indoor Wall Sawing Use water-fed system that delivers water continuously on blade, 100 series filtering face piece respirator
operated via remote control with natural ventilation.
Outdoor Hand Sawing Use water-fed system that delivers water continuously on blade Not Required
with natural ventilation.
OR Not Required
Use vacuum system at point of operation with natural ventilation.
Indoor Hand Sawing Use water-fed system that delivers water continuously on blade 100 series filtering face piece respirator
with natural ventilation.
TABLE 5 Core Drilling
Operation/Task Control Measures Respiratory Protection
Core Drilling Use water-fed system that delivers water continuously at the cut Not Required
point with natural ventilation
OR None
Dry Method: Use vacuum system at point of operation with OR
natural ventilation. 100 series filtering face piece respirators
Handheld tools with core drilling bits Use water-fed system that delivers water continuously at the cut None
point with natural ventilation. OR
100 series filtering face piece respirators
OR None
Use vacuum system at point of operation with natural ventilation. OR
100 series filtering face piece respirators
vacuum cleaners or water spray, wet floor sweepers, and PEL or company-adopted level. Where the use of personal
rotation of personnel to minimize individual exposure. respiratory protection is required under this practice, the
employer shall establish and enforce a program.
5.5 Respiratory Protection:
5.5.2 The employer shall institute a respiratory protection
5.5.1 Respirators shall be required in work situations in
which engineering and work practice controls are not sufficient program that includes: individual medical clearance for respi-
to reduce exposures of employees to or below the applicable rator usage, worker training in the use and limitations of
E2625 − 19
respirators, routine air monitoring, and the inspection, surveillance with spirometry is useful for early detection of
cleaning, maintenance, selection, and proper storage of respi- silica-induced lung disease. Experience has shown that most
rators. This training shall be done at first employment and abnormalities on screening spirometry are not due to work-
annually as refresher training.Any respiratory protection must, related disorders. Smoking, non-occupational pulmonary
at a minimum, meet the requirements of 29 CFR 1910.134 and disease, and other variables are more common causes of
ANSI Z88.2. Respirators shall be used according to the alterations in pulmonary function. Provided spirometry is
manufacturer’s instructions. See 5.4.1 for recommended respi- conducted, ensure that pulmonary function measurements are
rato
...

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 (Reapproved 2017) E2625 − 19
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, 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.
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
E1542 Terminology Relating to Occupational Health and Safety
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 Nov. 1, 2017Aug. 15, 2019. Published November 1, 2017August 2019. Originally approved in 2009. Last previous edition approved in 20092017
as E2625 – 09.E2625 – 09 (2017). DOI: 10.1520/E2625-09R17.10.1520/E2625-19.
Smith, Deane K., “Opal, Cristobalite, and Tridymite: Noncrystallinity Versus Crystallinity, Nomenclature of the Silica Minerals and Bibliography,” Powder Diffraction,
Vol 13, 1998, pppp. 1–18.
Miles, W. J., “Crystalline Silica Analysis of Wyoming Bentonite by X-ray Diffraction After Phosphoric Acid Digestion,” Analytical Chemistry Acta, Vol 286, 1994, pppp.
97–105.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2625 − 19
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
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. Terminology
3.1 For definitions not in this standard related to this practice, refer to Terminology E1542.
4. Significance and Use
4.1 These practices and criteria were developed for occupational exposures during construction and demolition activities. They
are intended to (a1) protect against clinically significant disease from exposure to respirable crystalline silica, (b2) be measurable
by techniques that are valid, reproducible, and readily available, and (c3) be attainable with existing technology and protective
practices.
5. General Requirements
5.1 Occupational Exposure Limit:
5.1.1 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 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#
PEL mg/m total dust 5 30÷ % quartz1 % cristobalite 32 1 % tridymite 32 12
~ ! ~ ! @ ~ ! ~ ! #
PEL mg/m respirable fraction 5 10÷ % quartz1 % cristobalite 32 1 % tridymite 32 12
~ ! ~ ! @ ~ ! ~ ! #
5.1.2 Federal OSHA PEL is approximately equivalent to a quartz level of 100μg/m100 μg ⁄m .
5.1.3 Employer shall determine the appropriate PEL for their operation, but in no case shall the PEL be less stringent than the
applicable government limit.
5.2 Exposure Assessment and Monitoring:
5.2.1 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.
5.2.2 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 4.15.1, 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
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
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.
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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.
5.2.3 Recordkeeping required under this practice shall be maintained and made available for review by employees.
5.2.4 For workers with regular exposure to high silica concentrations who are placed inside of supplied air 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.
5.2.5 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
analysis involves investigating cause(s) for the excessive exposure, providing remedies, and conducting follow-up sampling to
document that exposures are below the PEL.
5.2.6 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.
5.2.7 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.
5.2.8 Respirable dust samples are to be collected in accordance with accepted methods. Refer to Test Method D4532.
5.2.9 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.
5.2.10 Analyze samples for silica content analysis by an AIHA-accredited laboratory.
5.3 Exposure Monitoring:
5.3.1 The employer shall provide employees with an explanation of the sampling procedure.
5.3.2 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.
5.3.3 Affected employees shall be provided with copies of their sampling results when returned by the laboratory and
explanations of the data.
5.4 Methods of Compliance:
5.4.1 Task-Based Control Strategies—Where exposure levels are known from empirical data, a task-based control strategy shall
be applied that matches tasks with controls. The following lists examples of this approach.
5.4.1.1 Abrasive Blasting—OSHA has already established standards for abrasive blasting work requiring ventilation (29 CFR
1926.57) and respiratory protection (29 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).
5.4.1.2 Other engineering controls with the potential to limit exposure are:
(1) Using alternative materials,
(2) Wet suppression systems, and
(3) Exhaust ventilation.
5.4.1.3 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 doesdo not apply to occasional cutting limited to 90 min total time
5.4.2 Exposure-Based Control Strategies—Where exposure levels are measured and known to exceed the PEL, an exposure-
based control strategy shall be applied that uses the appropriate controls to lower exposure.
5.4.2.1 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,cabs designed for protection against respirable
crystalline silica dust, shall be provided with filtered air to reduce exposures.
(4) Engineering design of tools and equipment shall include, where feasible, provisions to minimize exposure of workers to
respirable crystalline silica dust to the PEL or below. If ventilation systems are used, they shall be designed and maintained to
prevent the accumulation and re-circulation of respirable crystalline silica dust in the working environment (see ANSI Z9.2). If
wet suppression systems are used, spray nozzles and associated piping shall be maintained to ensure that adequate wetting agent
is applied where needed to control respirable crystalline silica dust.
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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.
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.
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.
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 Protection
Tuck Pointing The following control measures may be useful in reducing exposure These types of respiratory protection will be necessary to
levels but may not be adequate to reliably reduce exposures below provide adequate protection in the absence of control meth-
the PEL. ods that demonstrate compliance with the PEL:
Ventilation Full face respirator with 100 series filter
Natural OR
Mechanical Supplied air respirator
Dust collection/vacuum
Shroud
Gauge/Guide for Equipment
Wet methods
Tuck Pointing The following control measures may be useful in reducing exposure These types of respiratory protection will be necessary to
levels but may not be adequate to reliably reduce exposures below provide adequate protection in the absence of control meth-
the PEL. ods that demonstrate compliance with the PEL:
Ventilation Full-face respirator with 100 series filter
Natural OR
Mechanical Supplied-air respirator
Dust collection/vacuum
Shroud
Gauge/Guide for Equipment
Wet methods
(5) All engineering controls shall be properly maintained and periodically evaluated and brought up to specifications, when
needed.
5.4.3 Work Practices and Administrative Controls:
5.4.3.1 Ensure that workers do not work in areas of visible dust generated from materials known to contain a significant
percentage of respirable crystalline silica without use of respiratory protection, unless proven task protection is in use or air
sampling shows exposures less than the PEL.
5.4.3.2 Workers shall not use compressed air to blow respirable crystalline silica-containing materials from surfaces or clothing,
unless the method has been approved by an appropriate regulatory agency.
5.4.3.3 Employers shall instruct workers about specific work practices that minimize exposure to respirable crystalline silica.
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TABLE 4 Concrete Cutting
Operation/Task Control Measures Respiratory Protection
Outdoor Slab Sawing Use water-fed system that delivers water continuously at the cut Not Required
point with natural ventilation OR Early entry sawing OR Dry
cutting with integrated vacuum system
Indoor Slab Sawing Use water-fed system that delivers water continuously at the cut 100 series filtering face piece respirator
point with natural ventilation.
OR 100 series filtering face piece respirator
Mechanical ventilation (fans)
OR 100 series filtering face piece respirator
Early entry sawing
OR
Dry cutting with integrated vacuum system
Outdoor Wire Sawing w/ remote Use water-fed system that delivers water continuously on wire, Not Required
Outdoor Wire Sawing w/o remote operated via remote control with natural ventilation.
Outdoor Wall Sawing Use water-fed system that delivers water continuously on blade Not Required
with natural ventilation.
Indoor Wall Sawing Use water-fed system that delivers water continuously on blade, 100 series filtering face piece respirator
operated via remote control with natural ventilation.
Outdoor Hand Sawing Use water-fed system that delivers water continuously on blade Not Required
with natural ventilation.
OR Not Required
Use vacuum system at point of operation with natural ventilation.
Indoor Hand Sawing Use water-fed system that delivers water continuously on blade 100 series filtering face piece respirator
with natural ventilation.
TABLE 5 Core Drilling
Operation/Task Control Measures Respiratory Protection
Core Drilling Use water-fed system that delivers water continuously at the cut Not Required
point with natural ventilation
OR None
Dry Method: Use vacuum system at point of operation with OR
natural ventilation. 100 series filtering face piece respirators
OR None
Dry Method: Use vacuum system at point of operation with OR
natural ventilation. 100 series filtering face piece respirators
Handheld tools with core drilling bits Use water-fed system that delivers water continuously at the cut None
point with natural ventilation. OR
100 series filtering face piece respirators
OR None
Use vacuum system at point of operation with natural ventilation. OR
100 series filtering face piece respirators
5.4.3.4 Workers shall utilize good housekeeping practices to minimize the generation and accumulation of dust.
5.4.3.5 Workers shall utilize available means to reduce exposure to dust, including the use of respirators, rest areas, ventilation
systems, high efficiency particulate air (HEPA) vacuum cleaners or water spray, wet floor sweepers, and rotation of personnel to
minimize individual exposure.
5.5 Respiratory Protection:
5.5.1 Respirators shall be required in work situations in which engineering and work practice controls are not sufficient to
reduce exposures of employees to or below the applicable PEL or company-adopted level. Where the use of personal respiratory
protection is required under this practice, the employer shall establish and enforce a program.
5.5.2 The employer shall institute a respiratory protection program that includes: individual medical clearance for respirator
usage, worker training in the use and limitations of respirators, routine air monitoring, and the inspection, cleaning, maintenance,
selection, and proper storage of respirators. This training shall be done at first
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