[Federal Register Volume 78, Number 177 (Thursday, September 12, 2013)]
[Proposed Rules]
[Pages 56273-56504]
[FR Doc No: 2013-20997]

Vol. 78

Thursday,

No. 177

September 12, 2013

Part II

Department of Labor

-----------------------------------------------------------------------

Occupational Safety and Health Administration

-----------------------------------------------------------------------

29 CFR Parts 1910, 1915, and 1926

Occupational Exposure to Respirable Crystalline Silica; Proposed Rule

Federal Register / Vol. 78 , No. 177 / Thursday, September 12, 2013 /
Proposed Rules

-----------------------------------------------------------------------

DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Parts 1910, 1915, and 1926

[Docket No. OSHA-2010-0034]
RIN 1218-AB70

Occupational Exposure to Respirable Crystalline Silica

AGENCY: Occupational Safety and Health Administration (OSHA),
Department of Labor.

ACTION: Proposed rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: The Occupational Safety and Health Administration (OSHA)
proposes to amend its existing standards for occupational exposure to
respirable crystalline silica. The basis for issuance of this proposal
is a preliminary determination by the Assistant Secretary of Labor for
Occupational Safety and Health that employees exposed to respirable
crystalline silica face a significant risk to their health at the
current permissible exposure limits and that promulgating these
proposed standards will substantially reduce that risk.
    This document proposes a new permissible exposure limit, calculated
as an 8-hour time-weighted average, of 50 micrograms of respirable
crystalline silica per cubic meter of air (50 [mu]g/m\3\). OSHA also
proposes other ancillary provisions for employee protection such as
preferred methods for controlling exposure, respiratory protection,
medical surveillance, hazard communication, and recordkeeping. OSHA is
proposing two separate regulatory texts--one for general industry and
maritime, and the other for construction--in order to tailor
requirements to the circumstances found in these sectors.

DATES: Written comments. Written comments, including comments on the
information collection determination described in Section IX of the
preamble (OMB Review under the Paperwork Reduction Act of 1995), must
be submitted (postmarked, sent, or received) by December 11, 2013.
    Informal public hearings. The Agency plans to hold informal public
hearings beginning on March 4, 2014, in Washington, DC. OSHA expects
the hearings to last from 9:30 a.m. to 5:30 p.m., local time; a
schedule will be released prior to the start of the hearings. The exact
daily schedule may be amended at the discretion of the presiding
administrative law judge (ALJ). If necessary, the hearings will
continue at the same time on subsequent days. Peer reviewers of OSHA's
Health Effects Literature Review and Preliminary Quantitative Risk
Assessment will be present in Washington, DC to hear testimony on the
second day of the hearing, March 5, 2014; see Section XV for more
information on the peer review process.
    Notice of intention to appear at the hearings. Interested persons
who intend to present testimony or question witnesses at the hearings
must submit (transmit, send, postmark, deliver) a notice of their
intention to do so by November 12, 2013. The notice of intent must
indicate if the submitter requests to present testimony in the presence
of the peer reviewers.
    Hearing testimony and documentary evidence. Interested persons who
request more than 10 minutes to present testimony, or who intend to
submit documentary evidence, at the hearings must submit (transmit,
send, postmark, deliver) the full text of their testimony and all
documentary evidence by December 11, 2013. See Section XV below for
details on the format and how to file a notice of intention to appear,
submit documentary evidence at the hearing, and request an appropriate
amount of time to present testimony.

ADDRESSES: Written comments. You may submit comments, identified by
Docket No. OSHA-2010-0034, by any of the following methods:
    Electronically: You may submit comments and attachments
electronically at http://www.regulations.gov, which is the Federal e-
Rulemaking Portal. Follow the instructions on-line for making
electronic submissions.
    Fax: If your submissions, including attachments, are not longer
than 10 pages, you may fax them to the OSHA Docket Office at (202) 693-
1648.
    Mail, hand delivery, express mail, messenger, or courier service:
You must submit your comments to the OSHA Docket Office, Docket No.
OSHA-2010-0034, U.S. Department of Labor, Room N-2625, 200 Constitution
Avenue NW., Washington, DC 20210, telephone<PHONE_NUMBER> (OSHA's TTY
number is<PHONE_NUMBER>). Deliveries (hand, express mail, messenger,
or courier service) are accepted during the Department of Labor's and
Docket Office's normal business hours, 8:15 a.m.-4:45 p.m., E.T.
    Instructions: All submissions must include the Agency name and the
docket number for this rulemaking (Docket No. OSHA-2010-0034). All
comments, including any personal information you provide, are placed in
the public docket without change and may be made available online at
http://www.regulations.gov. Therefore, OSHA cautions you about
submitting personal information such as social security numbers and
birthdates.
    If you submit scientific or technical studies or other results of
scientific research, OSHA requests (but is not requiring) that you also
provide the following information where it is available: (1)
Identification of the funding source(s) and sponsoring organization(s)
of the research; (2) the extent to which the research findings were
reviewed by a potentially affected party prior to publication or
submission to the docket, and identification of any such parties; and
(3) the nature of any financial relationships (e.g., consulting
agreements, expert witness support, or research funding) between
investigators who conducted the research and any organization(s) or
entities having an interest in the rulemaking. If you are submitting
comments or testimony on the Agency's scientific and technical
analyses, OSHA requests that you disclose: (1) The nature of any
financial relationships you may have with any organization(s) or
entities having an interest in the rulemaking; and (2) the extent to
which your comments or testimony were reviewed by an interested party
prior to its submission. Disclosure of such information is intended to
promote transparency and scientific integrity of data and technical
information submitted to the record. This request is consistent with
Executive Order 13563, issued on January 18, 2011, which instructs
agencies to ensure the objectivity of any scientific and technological
information used to support their regulatory actions. OSHA emphasizes
that all material submitted to the rulemaking record will be considered
by the Agency to develop the final rule and supporting analyses.
    Informal public hearings. The Washington, DC hearing will be held
in the auditorium of the U.S. Department of Labor, 200 Constitution
Avenue NW., Washington, DC 20210.
    Notice of intention to appear, hearing testimony and documentary
evidence. You may submit (transmit, send, postmark, deliver) your
notice of intention to appear, hearing testimony, and documentary
evidence, identified by docket number (OSHA-2010-0034), by any of the
following methods:
    Electronically: http://www.regulations.gov. Follow the instructions
online for electronic submission of materials, including attachments.

    Fax: If your written submission does not exceed 10 pages, including
attachments, you may fax it to the OSHA Docket Office at (202) 693-
1648.
    Regular mail, express delivery, hand delivery, and messenger and
courier service: Submit your materials to the OSHA Docket Office,
Docket No. OSHA-2010-0034, U.S. Department of Labor, Room N-2625, 200
Constitution Avenue NW., Washington, DC 20210; telephone<PHONE_NUMBER>
(TTY number<PHONE_NUMBER>). Deliveries (express mail, hand delivery,
and messenger and courier service) are accepted during the Department
of Labor's and OSHA Docket Office's normal hours of operation, 8:15
a.m. to 4:45 p.m., ET.
    Instructions: All submissions must include the Agency name and
docket number for this rulemaking (Docket No. OSHA-2010-0034). All
submissions, including any personal information, are placed in the
public docket without change and may be available online at http://www.regulations.gov. Therefore, OSHA cautions you about submitting
certain personal information, such as social security numbers and
birthdates. Because of security-related procedures, the use of regular
mail may cause a significant delay in the receipt of your submissions.
For information about security-related procedures for submitting
materials by express delivery, hand delivery, messenger, or courier
service, please contact the OSHA Docket Office. For additional
information on submitting notices of intention to appear, hearing
testimony or documentary evidence, see Section XV of this preamble,
Public Participation.
    Docket: To read or download comments, notices of intention to
appear, and materials submitted in response to this Federal Register
notice, go to Docket No. OSHA-2010-0034 at http://www.regulations.gov
or to the OSHA Docket Office at the address above. All comments and
submissions are listed in the http://www.regulations.gov index;
however, some information (e.g., copyrighted material) is not publicly
available to read or download through that Web site. All comments and
submissions are available for inspection and, where permissible,
copying at the OSHA Docket Office.
    Electronic copies of this Federal Register document are available
at http://regulations.gov. Copies also are available from the OSHA
Office of Publications, Room N-3101, U.S. Department of Labor, 200
Constitution Avenue NW., Washington, DC 20210; telephone (202) 693-
1888. This document, as well as news releases and other relevant
information, is also available at OSHA's Web site at http://www.osha.gov.

FOR FURTHER INFORMATION CONTACT: For general information and press
inquiries, contact Frank Meilinger, Director, Office of Communications,
Room N-3647, OSHA, U.S. Department of Labor, 200 Constitution Avenue
NW., Washington, DC 20210; telephone<PHONE_NUMBER>. For technical
inquiries, contact William Perry or David O'Connor, Directorate of
Standards and Guidance, Room N-3718, OSHA, U.S. Department of Labor,
200 Constitution Avenue NW., Washington, DC 20210; telephone (202) 693-
1950 or fax<PHONE_NUMBER>. For hearing inquiries, contact Frank
Meilinger, Director, Office of Communications, Room N-3647, OSHA, U.S.
Department of Labor, 200 Constitution Avenue NW., Washington, DC 20210;
telephone<PHONE_NUMBER>; email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:
    The preamble to the proposed standard on occupational exposure to
respirable crystalline silica follows this outline:

I. Issues
II. Pertinent Legal Authority
III. Events Leading to the Proposed Standards
IV. Chemical Properties and Industrial Uses
V. Health Effects Summary
VI. Summary of the Preliminary Quantitative Risk Assessment
VII. Significance of Risk
VIII. Summary of the Preliminary Economic Analysis and Initial
Regulatory Flexibility Analysis
IX. OMB Review Under the Paperwork Reduction Act of 1995
X. Federalism
XI. State Plans
XII. Unfunded Mandates
XIII. Protecting Children From Environmental Health and Safety Risks
XIV. Environmental Impacts
XV. Public Participation
XVI. Summary and Explanation of the Standards
    (a) Scope and Application
    (b) Definitions
    (c) Permissible Exposure Limit (PEL)
    (d) Exposure Assessment
    (e) Regulated Areas and Access Control
    (f) Methods of Compliance
    (g) Respiratory Protection
    (h) Medical Surveillance
    (i) Communication of Respirable Crystalline Silica Hazards to
Employees
    (j) Recordkeeping
    (k) Dates
XVII. References
XVIII. Authority and Signature

    OSHA currently enforces permissible exposure limits (PELs) for
respirable crystalline silica in general industry, construction, and
shipyards. These PELs were adopted in 1971, shortly after the Agency
was created, and have not been updated since then. The PEL for quartz
(the most common form of crystalline silica) in general industry is a
formula that is approximately equivalent to 100 micrograms per cubic
meter of air ([mu]g/m\3\) as an 8-hour time-weighted average. The PEL
for quartz in construction and shipyards is a formula based on a now-
obsolete particle count sampling method that is approximately
equivalent to 250 [mu]g/m\3\. The current PELs for two other forms of
crystalline silica (cristobalite and tridymite) are one-half of the
values for quartz in general industry. OSHA is proposing a new PEL for
respirable crystalline silica (quartz, cristobalite, and tridymite) of
50 [mu]g/m\3\ in all industry sectors covered by the rule. OSHA is also
proposing other elements of a comprehensive health standard, including
requirements for exposure assessment, preferred methods for controlling
exposure, respiratory protection, medical surveillance, hazard
communication, and recordkeeping.
    OSHA's proposal is based on the requirements of the Occupational
Safety and Health Act (OSH Act) and court interpretations of the Act.
For health standards issued under section 6(b)(5) of the OSH Act, OSHA
is required to promulgate a standard that reduces significant risk to
the extent that it is technologically and economically feasible to do
so. See Section II of this preamble, Pertinent Legal Authority, for a
full discussion of OSHA legal requirements.
    OSHA has conducted an extensive review of the literature on adverse
health effects associated with exposure to respirable crystalline
silica. The Agency has also developed estimates of the risk of silica-
related diseases assuming exposure over a working lifetime at the
proposed PEL and action level, as well as at OSHA's current PELs. These
analyses are presented in a background document entitled ``Respirable
Crystalline Silica--Health Effects Literature Review and Preliminary
Quantitative Risk Assessment'' and are summarized in this preamble in
Section V, Health Effects Summary, and Section VI, Summary of OSHA's
Preliminary Quantitative Risk Assessment, respectively. The available
evidence indicates that employees exposed to respirable crystalline
silica well below the current PELs are at increased risk of lung cancer
mortality and silicosis mortality and morbidity. Occupational exposures
to respirable crystalline silica also may result in the development of
kidney and autoimmune diseases and in death from other nonmalignant
respiratory diseases, including chronic obstructive pulmonary disease
(COPD).

As discussed in Section VII, Significance of Risk, in this preamble,
OSHA preliminarily finds that worker exposure to respirable crystalline
silica constitutes a significant risk and that the proposed standard
will substantially reduce this risk.
    Section 6(b) of the OSH Act requires OSHA to determine that its
standards are technologically and economically feasible. OSHA's
examination of the technological and economic feasibility of the
proposed rule is presented in the Preliminary Economic Analysis and
Initial Regulatory Flexibility Analysis (PEA), and is summarized in
Section VIII of this preamble. For general industry and maritime, OSHA
has preliminarily concluded that the proposed PEL of 50 [mu]g/m\3\ is
technologically feasible for all affected industries. For construction,
OSHA has preliminarily determined that the proposed PEL of 50 [mu]g/
m\3\ is feasible in 10 out of 12 of the affected activities. Thus, OSHA
preliminarily concludes that engineering and work practices will be
sufficient to reduce and maintain silica exposures to the proposed PEL
of 50 [mu]g/m\3\ or below in most operations most of the time in the
affected industries. For those few operations within an industry or
activity where the proposed PEL is not technologically feasible even
when workers use recommended engineering and work practice controls,
employers can supplement controls with respirators to achieve exposure
levels at or below the proposed PEL.
    OSHA developed quantitative estimates of the compliance costs of
the proposed rule for each of the affected industry sectors. The
estimated compliance costs were compared with industry revenues and
profits to provide a screening analysis of the economic feasibility of
complying with the revised standard and an evaluation of the potential
economic impacts. Industries with unusually high costs as a percentage
of revenues or profits were further analyzed for possible economic
feasibility issues. After performing these analyses, OSHA has
preliminarily concluded that compliance with the requirements of the
proposed rule would be economically feasible in every affected industry
sector.
    OSHA directed Inforum--a not-for-profit corporation (based at the
University of Maryland) well recognized for its macroeconomic
modeling--to run its LIFT (Long-term Interindustry Forecasting Tool)
model of the U.S. economy to estimate the industry and aggregate
employment effects of the proposed silica rule. Inforum developed
estimates of the employment impacts over the ten-year period from 2014-
2023 by feeding OSHA's year-by-year and industry-by-industry estimates
of the compliance costs of the proposed rule into its LIFT model. Based
on the resulting Inforum estimates of employment impacts, OSHA has
preliminarily concluded that the proposed rule would have a
negligible--albeit slightly positive--net impact on aggregate U.S.
employment.
    OSHA believes that a new PEL, expressed as a gravimetric
measurement of respirable crystalline silica, will improve compliance
because the PEL is simple and relatively easy to understand. In
comparison, the existing PELs require application of a formula to
account for the crystalline silica content of the dust sampled and, in
the case of the construction and shipyard PELs, a conversion from
particle count to mg/m\3\ as well. OSHA also expects that the approach
to methods of compliance for construction operations included in this
proposal will improve compliance with the standard. This approach,
which specifies exposure control methods for selected construction
operations, gives employers a simple option to identify the control
measures that are appropriate for these operations. Alternately,
employers could conduct exposure assessments to determine if worker
exposures are in compliance with the PEL. In either case, the proposed
rule would provide a basis for ensuring that appropriate measures are
in place to limit worker exposures.
    The Regulatory Flexibility Act, as amended by the Small Business
Regulatory Enforcement Fairness Act (SBREFA), requires that OSHA either
certify that a rule would not have a significant economic impact on a
substantial number of small firms or prepare a regulatory flexibility
analysis and hold a Small Business Advocacy Review (SBAR) Panel prior
to proposing the rule. OSHA has determined that a regulatory
flexibility analysis is needed and has provided this analysis in
Section VIII.G of this preamble. OSHA also previously held a SBAR Panel
for this rule. The recommendations of the Panel and OSHA's response to
them are summarized in Section VIII.G of this preamble.
    Executive Orders 13563 and 12866 direct agencies to assess all
costs and benefits of available regulatory alternatives. Executive
Order 13563 emphasizes the importance of quantifying both costs and
benefits, of reducing costs, of harmonizing rules, and of promoting
flexibility. This rule has been designated an economically significant
regulatory action under section 3(f)(1) of Executive Order 12866.
Accordingly, the rule has been reviewed by the Office of Management and
Budget, and the remainder of this section summarizes the key findings
of the analysis with respect to costs and benefits of the rule and then
presents several possible alternatives to the rule.
    Table SI-1--which, like all the tables in this section, is derived
from material presented in Section VIII of this preamble--provides a
summary of OSHA's best estimate of the costs and benefits of the
proposed rule using a discount rate of 3 percent. As shown, the
proposed rule is estimated to prevent 688 fatalities and 1,585 silica-
related illnesses annually once it is fully effective, and the
estimated cost of the rule is $637 million annually. Also as shown in
Table SI-1, the discounted monetized benefits of the proposed rule are
estimated to be $5.3 billion annually, and the proposed rule is
estimated to generate net benefits of $4.6 billion annually. These
estimates are for informational purposes only and have not been used by
OSHA as the basis for its decision concerning the choice of a PEL or of
other ancillary requirements for this proposed silica rule. The courts
have ruled that OSHA may not use benefit-cost analysis or a criterion
of maximizing net benefits as a basis for setting OSHA health
standards.\1\
---------------------------------------------------------------------------

    \1\ Am. Textile Mfrs. Inst., Inc. v. Nat'l Cotton Council of
Am., 452 U.S. 490, 513 (1981); Pub. Citizen Health Research Group v.
U.S. Dep't of Labor, 557 F.3d 165, 177 (3d Cir. 2009); Friends of
the Boundary Waters Wilderness v. Robertson, 978 F.2d 1484, 1487
(8th Cir. 1992).

---------------------------------------------------------------------------

[GRAPHIC] [TIFF OMITTED] TP12SE13.000

    Both the costs and benefits of Table SI-1 reflect the incremental
costs and benefits associated with achieving full compliance with the
proposed rule. They do not include (a) costs and benefits associated
with current compliance that have already been achieved with regard to
the new requirements, or (b) costs and benefits associated with
achieving compliance with existing requirements, to the extent that
some employers may currently not be fully complying with applicable
regulatory requirements. They also do not include costs or benefits
associated with relatively rare, extremely high exposures that can lead
to acute silicosis.
    Subsequent to completion of the PEA, OSHA identified an industry,
hydraulic fracturing, that would be impacted by the proposed standard.
Hydraulic fracturing, sometimes called ``fracking,'' is a process used
to extract natural gas and oil deposits from shale and other tight
geologic formations. A recent cooperative study by the National
Institute for Occupational Safety and Health (NIOSH) and industry
partners identified overexposures to silica among workers conducting
hydraulic fracturing operations. An industry focus group has been
working with OSHA and NIOSH to disseminate information about this
hazard, share best practices, and develop engineering controls to limit
worker exposures to silica. OSHA finds that there are now sufficient
data to provide the main elements of the economic analysis for this
rapidly growing industry and has done so in Appendix A to the PEA.
    Based on recent data from the U.S. Census Bureau and industry
sources, OSHA estimates that roughly 25,000 workers in 444
establishments (operated by 200 business entities) in hydraulic
fracturing would be affected by the proposed standard. Annual benefits
of the proposed 50 [mu]g/m\3\ PEL include approximately 12 avoided
fatalities--2.9 avoided lung cancers (mid-point estimate), 6.3
prevented non-cancer respiratory illnesses, and 2.3 prevented cases of
renal failure--and 40.8 avoided cases of silicosis morbidity. Monetized
benefits are expected to range from $75.1 million at a seven percent
discount rate to $105.4 million at a three percent discount rate to
undiscounted benefits of $140.3 million. OSHA estimates that under the
proposed standard, annualized compliance costs for the hydraulic
fracturing industry will total $28.6 million at a discount rate of 7
percent or $26.4 million at a discount rate of 3 percent.
    In addition to the proposed rule itself, this preamble discusses
several regulatory alternatives to the proposed OSHA silica standard.
These are presented below as well as in Section VIII of this preamble.
OSHA believes that this presentation of regulatory alternatives serves
two important functions. The first is to explore the possibility of
less costly ways (than the proposed rule) to provide an adequate level
of worker protection from exposure to respirable crystalline silica.
The second is tied to the Agency's statutory requirement, which
underlies the proposed rule, to reduce significant risk to the extent
feasible. If, based on evidence presented during notice and comment,
OSHA is unable to justify its preliminary findings of significant risk
and feasibility as presented in this preamble to the proposed rule, the
Agency must then consider regulatory alternatives that do satisfy its
statutory obligations.

    Each regulatory alternative presented here is described and
analyzed relative to the proposed rule. Where appropriate, the Agency
notes whether the regulatory alternative, to be a legitimate candidate
for OSHA consideration, requires evidence contrary to the Agency's
findings of significant risk and feasibility. To facilitate comment,
the regulatory alternatives have been organized into four categories:
(1) Alternative PELs to the proposed PEL of 50 [mu]g/m\3\; (2)
regulatory alternatives that affect proposed ancillary provisions; (3)
a regulatory alternative that would modify the proposed methods of
compliance; and (4) regulatory alternatives concerning when different
provisions of the proposed rule would take effect.
    In addition, OSHA would like to draw attention to one possible
modification to the proposed rule, involving methods of compliance,
that the Agency would not consider to be a legitimate regulatory
alternative: To permit the use of respiratory protection as an
alternative to engineering and work practice controls as a primary
means to achieve the PEL.
    As described in Section XVI of the preamble, Summary and
Explanation of the Proposed Standards, OSHA is proposing to require
primary reliance on engineering controls and work practices because
reliance on these methods is consistent with long-established good
industrial hygiene practice, with the Agency's experience in ensuring
that workers have a healthy workplace, and with the Agency's
traditional adherence to a hierarchy of preferred controls. The
Agency's adherence to the hierarchy of controls has been successfully
upheld by the courts (see AFL-CIO v. Marshall, 617 F.2d 636 (D.C. Cir.
1979) (cotton dust standard); United Steelworkers v. Marshall, 647 F.2d
1189 (D.C. Cir. 1980), cert. denied, 453 U.S. 913 (1981) (lead
standard); ASARCO v. OSHA, 746 F.2d 483 (9th Cir. 1984) (arsenic
standard); Am. Iron & Steel v. OSHA, 182 F.3d 1261 (11th Cir. 1999)
(respiratory protection standard); Pub. Citizen v. U.S. Dep't of Labor,
557 F.3d 165 (3rd Cir. 2009) (hexavalent chromium standard)).
    Engineering controls are reliable, provide consistent levels of
protection to a large number of workers, can be monitored, allow for
predictable performance levels, and can efficiently remove a toxic
substance from the workplace. Once removed, the toxic substance no
longer poses a threat to employees. The effectiveness of engineering
controls does not generally depend on human behavior to the same extent
as personal protective equipment does, and the operation of equipment
is not as vulnerable to human error as is personal protective
equipment.
    Respirators are another important means of protecting workers.
However, to be effective, respirators must be individually selected;
fitted and periodically refitted; conscientiously and properly worn;
regularly maintained; and replaced as necessary. In many workplaces,
these conditions for effective respirator use are difficult to achieve.
The absence of any of these conditions can reduce or eliminate the
protection that respirators provide to some or all of the employees who
wear them.
    In addition, use of respirators in the workplace presents other
safety and health concerns. Respirators impose substantial
physiological burdens on some employees. Certain medical conditions can
compromise an employee's ability to tolerate the physiological burdens
imposed by respirator use, thereby placing the employee wearing the
respirator at an increased risk of illness, injury, and even death.
Psychological conditions, such as claustrophobia, can also impair the
effective use of respirators by employees. These concerns about the
burdens placed on workers by the use of respirators are the basis for
the requirement that employers provide a medical evaluation to
determine the employee's ability to wear a respirator before the
employee is fit tested or required to use a respirator in the
workplace. Although experience in industry shows that most healthy
workers do not have physiological problems wearing properly chosen and
fitted respirators, common health problems can sometime preclude an
employee from wearing a respirator. Safety problems created by
respirators that limit vision and communication must also be
considered. In some difficult or dangerous jobs, effective vision or
communication is vital. Voice transmission through a respirator can be
difficult and fatiguing.
    Because respirators are less reliable than engineering and work
practice controls and may create additional problems, OSHA believes
that primary reliance on respirators to protect workers is generally
inappropriate when feasible engineering and work practice controls are
available. All OSHA substance-specific health standards have recognized
and required employers to observe the hierarchy of controls, favoring
engineering and work practice controls over respirators. OSHA's PELs,
including the current PELs for respirable crystalline silica, also
incorporate this hierarchy of controls. In addition, the industry
consensus standards for crystalline silica (ASTM E 1132-06, Standard
Practice for Health Requirements Relating to Occupational Exposure to
Respirable Crystalline Silica, and ASTM E 2626-09, Standard Practice
for Controlling Occupational Exposure to Respirable Crystalline Silica
for Construction and Demolition Activities) incorporate the hierarchy
of controls.
    It is important to note that the very concept of technological
feasibility for OSHA standards is grounded in the hierarchy of
controls. As indicated in Section II of this preamble, Pertinent Legal
Authority, the courts have clarified that a standard is technologically
feasible if OSHA proves a reasonable possibility,

. . . within the limits of the best available evidence . . . that
the typical firm will be able to develop and install engineering and
work practice controls that can meet the PEL in most of its
operations. [See United Steelworkers v. Marshall, 647 F.2d 1189,
1272 (D.C. Cir. 1980)]

    Allowing use of respirators instead of engineering and work
practice controls would be at odds with this framework for evaluating
the technological feasibility of a PEL.

Alternative PELs

    OSHA has examined two regulatory alternatives (named Regulatory
Alternatives 1 and 2) that would modify the PEL for
the proposed rule. Under Regulatory Alternative 1, the
proposed PEL would be changed from 50 [mu]g/m\3\ to 100 [mu]g/m\3\ for
all industry sectors covered by the rule, and the action level would be
changed from 25 [mu]g/m\3\ to 50 [mu]g/m\3\ (thereby keeping the action
level at one-half of the PEL). Under Regulatory Alternative 2,
the proposed PEL would be lowered from 50 [mu]g/m\3\ to 25 [mu]g/m\3\
for all industry sectors covered by the rule, while the action level
would remain at 25 [mu]g/m\3\ (because of difficulties in accurately
measuring exposure levels below 25 [mu]g/m\3\).
    Tables SI-2 and SI-3 present, for informational purposes, the
estimated costs, benefits, and net benefits of the proposed rule under
the proposed PEL of 50 [mu]g/m\3\ and for the regulatory alternatives
of a PEL of 100 [mu]g/m\3\ and a PEL of 25 [mu]g/m\3\ (Regulatory
Alternatives 1 and 2), using alternative discount
rates of 3 and 7 percent. These two tables also present the incremental
costs, the incremental benefits, and the incremental net benefits of
going from a PEL of 100 [mu]g/m\3\ to the proposed PEL of 50 [mu]g/m\3\
and then of going from the proposed PEL of 50 [mu]g/m\3\ to a PEL of 25
[mu]g/m\3\. Table

SI-2 breaks out costs by provision and benefits by type of disease and
by morbidity/mortality, while Table SI-3 breaks out costs and benefits
by major industry sector.
[GRAPHIC] [TIFF OMITTED] TP12SE13.001

[GRAPHIC] [TIFF OMITTED] TP12SE13.002

    As Tables SI-2 and SI-3 show, going from a PEL of 100 [mu]g/m\3\ to
a PEL of 50 [mu]g/m\3\ would prevent, annually, an additional 357
silica-related fatalities and an additional 632 cases of silicosis.
Based on its preliminary findings that the proposed PEL of 50 [mu]g/
m\3\ significantly reduces worker risk from silica exposure (as
demonstrated by the number of silica-related fatalities and silicosis
cases avoided) and is both technologically and economically

feasible, OSHA cannot propose a PEL of 100 [mu]g/m\3\ (Regulatory
Alternative 1) without violating its statutory obligations
under the OSH Act. However, the Agency will consider evidence that
challenges its preliminary findings.
    As previously noted, Tables SI-2 and SI-3 also show the costs and
benefits of a PEL of 25 [mu]g/m\3\ (Regulatory Alternative 2),
as well as the incremental costs and benefits of going from the
proposed PEL of 50 [mu]g/m\3\ to a PEL of 25 [mu]g/m\3\. Because OSHA
preliminarily determined that a PEL of 25 [mu]g/m\3\ would not be
feasible (that is, engineering and work practices would not be
sufficient to reduce and maintain silica exposures to a PEL of 25
[mu]g/m\3\ or below in most operations most of the time in the affected
industries), the Agency did not attempt to identify engineering
controls or their costs for affected industries to meet this PEL.
Instead, for purposes of estimating the costs of going from a PEL of 50
[mu]g/m\3\ to a PEL of 25 [mu]g/m\3\, OSHA assumed that all workers
exposed between 50 [mu]g/m\3\ and 25 [mu]g/m\3\ would have to wear
respirators to achieve compliance with the 25 [mu]g/m\3\ PEL. OSHA then
estimated the associated additional costs for respirators, exposure
assessments, medical surveillance, and regulated areas (the latter
three for ancillary requirements specified in the proposed rule).
    As shown in Tables SI-2 and SI-3, going from a PEL of 50 [mu]g/m\3\
to a PEL of 25 [mu]g/m\3\ would prevent, annually, an additional 335
silica-related fatalities and an additional 186 cases of silicosis.
These estimates support OSHA's preliminarily finding that there is
significant risk remaining at the proposed PEL of 50 [mu]g/m\3\.
However, the Agency has preliminarily determined that a PEL of 25
[mu]g/m\3\ (Regulatory Alternative 2) is not technologically
feasible, and for that reason, cannot propose it without violating its
statutory obligations under the OSH Act.

Regulatory Alternatives That Affect Ancillary Provisions

    The proposed rule contains several ancillary provisions (provisions
other than the PEL), including requirements for exposure assessment,
medical surveillance, training, and regulated areas or access control.
As shown in Table SI-2, these ancillary provisions represent
approximately $223 million (or about 34 percent) of the total
annualized costs of the rule of $658 million (using a 7 percent
discount rate). The two most expensive of the ancillary provisions are
the requirements for medical surveillance, with annualized costs of $79
million, and the requirements for exposure monitoring, with annualized
costs of $74 million.
    As proposed, the requirements for exposure assessment are triggered
by the action level. As described in this preamble, OSHA has defined
the action level for the proposed standard as an airborne concentration
of respirable crystalline silica of 25 [mu]g/m\3\ calculated as an
eight-hour time-weighted average. In this proposal, as in other
standards, the action level has been set at one-half of the PEL.
    Because of the variable nature of employee exposures to airborne
concentrations of respirable crystalline silica, maintaining exposures
below the action level provides reasonable assurance that employees
will not be exposed to respirable crystalline silica at levels above
the PEL on days when no exposure measurements are made. Even when all
measurements on a given day may fall below the PEL (but are above the
action level), there is some chance that on another day, when exposures
are not measured, the employee's actual exposure may exceed the PEL.
When exposure measurements are above the action level, the employer
cannot be reasonably confident that employees have not been exposed to
respirable crystalline silica concentrations in excess of the PEL
during at least some part of the work week. Therefore, requiring
periodic exposure measurements when the action level is exceeded
provides the employer with a reasonable degree of confidence in the
results of the exposure monitoring.
    The action level is also intended to encourage employers to lower
exposure levels in order to avoid the costs associated with the
exposure assessment provisions. Some employers would be able to reduce
exposures below the action level in all work areas, and other employers
in some work areas. As exposures are lowered, the risk of adverse
health effects among workers decreases.
    OSHA's preliminary risk assessment indicates that significant risk
remains at the proposed PEL of 50 [mu]g/m\3\. Where there is continuing
significant risk, the decision in the Asbestos case (Bldg. and Constr.
Trades Dep't, AFL-CIO v. Brock, 838 F.2d 1258, 1274 (D.C. Cir. 1988))
indicated that OSHA should use its legal authority to impose additional
requirements on employers to further reduce risk when those
requirements will result in a greater than de minimis incremental
benefit to workers' health. OSHA's preliminary conclusion is that the
requirements triggered by the action level will result in a very real
and necessary, but non-quantifiable, further reduction in risk beyond
that provided by the PEL alone. OSHA's choice of proposing an action
level for exposure monitoring of one-half of the PEL is based on the
Agency's successful experience with other standards, including those
for inorganic arsenic (29 CFR 1910.1018), ethylene oxide (29 CFR
1910.1047), benzene (29 CFR 1910.1028), and methylene chloride (29 CFR
1910.1052).
    As specified in the proposed rule, all workers exposed to
respirable crystalline silica above the PEL of 50 [mu]g/m\3\ are
subject to the medical surveillance requirements. This means that the
medical surveillance requirements would apply to 15,172 workers in
general industry and 336,244 workers in construction. OSHA estimates
that 457 possible silicosis cases will be referred to pulmonary
specialists annually as a result of this medical surveillance.
    OSHA has preliminarily determined that these ancillary provisions
will: (1) Help ensure that the PEL is not exceeded, and (2) minimize
risk to workers given the very high level of risk remaining at the PEL.
OSHA did not estimate, and the benefits analysis does not include,
monetary benefits resulting from early discovery of illness.
    Because medical surveillance and exposure assessment are the two
most costly ancillary provisions in the proposed rule, the Agency has
examined four regulatory alternatives (named Regulatory Alternatives
3, 4, 5, and 6) involving changes
to one or the other of these ancillary provisions. These four
regulatory alternatives are defined below and the incremental cost
impact of each is summarized in Table SI-4. In addition, OSHA is
including a regulatory alternative (named Regulatory Alternative
7) that would remove all ancillary provisions.

[GRAPHIC] [TIFF OMITTED] TP12SE13.003

    Under Regulatory Alternative 3, the action level would be
raised from 25 [mu]g/m\3\ to 50 [mu]g/m\3\ while keeping the PEL at 50
[mu]g/m\3\. As a result, exposure monitoring requirements would be
triggered only if workers were exposed

above the proposed PEL of 50 [mu]g/m\3\. As shown in Table SI-4,
Regulatory Option 3 would reduce the annualized cost of the
proposed rule by about $62 million, using a discount rate of either 3
percent or 7 percent.
    Under Regulatory Alternative 4, the action level would
remain at 25 [mu]g/m\3\ but medical surveillance would now be triggered
by the action level, not the PEL. As a result, medical surveillance
requirements would be triggered only if workers were exposed at or
above the proposed action level of 25 [mu]g/m\3\. As shown in Table SI-
4, Regulatory Option 4 would increase the annualized cost of
the proposed rule by about $143 million, using a discount rate of 3
percent (and by about $169 million, using a discount rate of 7
percent).
    Under Regulatory Alternative 5, the only change to the
proposed rule would be to the medical surveillance requirements.
Instead of requiring workers exposed above the PEL to have a medical
check-up every three years, those workers would be required to have a
medical check-up annually. As shown in Table SI-4, Regulatory Option
5 would increase the annualized cost of the proposed rule by
about $69 million, using a discount rate of 3 percent (and by about $66
million, using a discount rate of 7 percent).
    Regulatory Alternative 6 would essentially combine the
modified requirements in Regulatory Alternatives 4 and
5. Under Regulatory Alternative 6, medical
surveillance would be triggered by the action level, not the PEL, and
workers exposed at or above the action level would be required to have
a medical check-up annually rather than triennially. The exposure
monitoring requirements in the proposed rule would not be affected. As
shown in Table SI-4, Regulatory Option 6 would increase the
annualized cost of the proposed rule by about $342 million, using a
discount rate of either 3 percent or 7 percent.
    OSHA is not able to quantify the effects of these preceding four
regulatory alternatives on protecting workers exposed to respirable
crystalline silica at levels at or below the proposed PEL of 50 [mu]g/
m\3\--where significant risk remains. The Agency solicits comment on
the extent to which these regulatory options may improve or reduce the
effectiveness of the proposed rule.
    The final regulatory alternative affecting ancillary provisions,
Regulatory Alternative 7, would eliminate all of the ancillary
provisions of the proposed rule, including exposure assessment, medical
surveillance, training, and regulated areas or access control. However,
it should be carefully noted that elimination of the ancillary
provisions does not mean that all costs for ancillary provisions would
disappear. In order to meet the PEL, employers would still commonly
need to do monitoring, train workers on the use of controls, and set up
some kind of regulated areas to indicate where respirator use would be
required. It is also likely that employers would increasingly follow
the many recommendations to provide medical surveillance for employees.
OSHA has not attempted to estimate the extent to which the costs of
these activities would be reduced if they were not formally required,
but OSHA welcomes comment on the issue.
    As indicated previously, OSHA preliminarily finds that there is
significant risk remaining at the proposed PEL of 50 [mu]g/m\3\.
However, the Agency has also preliminarily determined that 50 [mu]g/
m\3\ is the lowest feasible PEL. Therefore, the Agency believes that it
is necessary to include ancillary provisions in the proposed rule to
further reduce the remaining risk. OSHA anticipates that these
ancillary provisions will reduce the risk beyond the reduction that
will be achieved by a new PEL alone.
    OSHA's reasons for including each of the proposed ancillary
provisions are detailed in Section XVI of this preamble, Summary and
Explanation of the Standards. In particular, OSHA believes that
requirements for exposure assessment (or alternately, using specified
exposure control methods for selected construction operations) would
provide a basis for ensuring that appropriate measures are in place to
limit worker exposures. Medical surveillance is particularly important
because individuals exposed above the PEL (which triggers medical
surveillance in the proposed rule) are at significant risk of death and
illness. Medical surveillance would allow for identification of
respirable crystalline silica-related adverse health effects at an
early stage so that appropriate intervention measures can be taken.
OSHA believes that regulated areas and access control are important
because they serve to limit exposure to respirable crystalline silica
to as few employees as possible. Finally, OSHA believes that worker
training is necessary to inform employees of the hazards to which they
are exposed, along with associated protective measures, so that
employees understand how they can minimize potential health hazards.
Worker training on silica-related work practices is particularly
important in controlling silica exposures because engineering controls
frequently require action on the part of workers to function
effectively.
    OSHA expects that the benefits estimated under the proposed rule
will not be fully achieved if employers do not implement the ancillary
provisions of the proposed rule. For example, OSHA believes that the
effectiveness of the proposed rule depends on regulated areas or access
control to further limit exposures and on medical surveillance to
identify disease cases when they do occur.
    Both industry and worker groups have recognized that a
comprehensive standard is needed to protect workers exposed to
respirable crystalline silica. For example, the industry consensus
standards for crystalline silica, ASTM E 1132-06, Standard Practice for
Health Requirements Relating to Occupational Exposure to Respirable
Crystalline Silica, and ASTM E 2626-09, Standard Practice for
Controlling Occupational Exposure to Respirable Crystalline Silica for
Construction and Demolition Activities, as well as the draft proposed
silica standard for construction developed by the Building and
Construction Trades Department, AFL-CIO, have each included
comprehensive programs. These recommended standards include provisions
for methods of compliance, exposure monitoring, training, and medical
surveillance (ASTM, 2006; 2009; BCTD 2001). Moreover, as mentioned
previously, where there is continuing significant risk, the decision in
the Asbestos case (Bldg. and Constr. Trades Dep't, AFL-CIO v. Brock,
838 F.2d 1258, 1274 (D.C. Cir. 1988)) indicated that OSHA should use
its legal authority to impose additional requirements on employers to
further reduce risk when those requirements will result in a greater
than de minimis incremental benefit to workers' health. OSHA
preliminarily concludes that the additional requirements in the
ancillary provisions of the proposed standard clearly exceed this
threshold.

A Regulatory Alternative That Modifies the Methods of Compliance

    The proposed standard in general industry and maritime would
require employers to implement engineering and work practice controls
to reduce employees' exposures to or below the PEL. Where engineering
and/or work practice controls are insufficient, employers would still
be required to implement them to reduce exposure as much as possible,
and to supplement them with a respiratory protection program. Under the
proposed construction standard, employers would

be given two options for compliance. The first option largely follows
requirements for the general industry and maritime proposed standard,
while the second option outlines, in Table 1 (Exposure Control Methods
for Selected Construction Operations) of the proposed rule, specific
construction exposure control methods. Employers choosing to follow
OSHA's proposed control methods would be considered to be in compliance
with the engineering and work practice control requirements of the
proposed standard, and would not be required to conduct certain
exposure monitoring activities.
    One regulatory alternative (Regulatory Alternative 8)
involving methods of compliance would be to eliminate Table 1 as a
compliance option in the construction sector. Under that regulatory
alternative, OSHA estimates that there would be no effect on estimated
benefits but that the annualized costs of complying with the proposed
rule (without the benefit of the Table 1 option in construction) would
increase by $175 million, totally in exposure monitoring costs, using a
3 percent discount rate (and by $178 million using a 7 percent discount
rate), so that the total annualized compliance costs for all affected
establishments in construction would increase from $495 to $670 million
using a 3 percent discount rate (and from $511 to $689 million using a
7 percent discount rate).

Regulatory Alternatives That Affect the Timing of the Standard

    The proposed rule would become effective 60 days following
publication of the final rule in the Federal Register. Provisions
outlined in the proposed standard would become enforceable 180 days
following the effective date, with the exceptions of engineering
controls and laboratory requirements. The proposed rule would require
engineering controls to be implemented no later than one year after the
effective date, and laboratory requirements would be required to begin
two years after the effective date.
    OSHA will strongly consider alternatives that would reduce the
economic impact of the rule and provide additional flexibility for
firms coming into compliance with the requirements of the rule. The
Agency solicits comment and suggestions from stakeholders, particularly
small business representatives, on options for phasing in requirements
for engineering controls, medical surveillance, and other provisions of
the rule (e.g., over 1, 2, 3, or more years). These options will be
considered for specific industries (e.g., industries where first-year
or annualized cost impacts are highest), specific size-classes of
employers (e.g., employers with fewer than 20 employees), combinations
of these factors, or all firms covered by the rule.
    Although OSHA did not explicitly develop or quantitatively analyze
the multitude of potential regulatory alternatives involving longer-
term or more complex phase-ins of the standard, the Agency is
soliciting comments on this issue. Such a particularized, multi-year
phase-in could have several advantages, especially from the viewpoint
of impacts on small businesses. First, it would reduce the one-time
initial costs of the standard by spreading them out over time, a
particularly useful mechanism for small businesses that have trouble
borrowing large amounts of capital in a single year. Second, a
differential phase-in for smaller firms would aid very small firms by
allowing them to gain from the control experience of larger firms.
Finally, a phase-in would be useful in certain industries--such as
foundries, for example--by allowing employers to coordinate their
environmental and occupational safety and health control strategies to
minimize potential costs. However a phase-in would also postpone the
benefits of the standard.
    OSHA analyzed one regulatory alternative (Regulatory Alternative
9) involving the timing of the standard which would arise if,
contrary to OSHA's preliminary findings, a PEL of 50 [micro]g/m\3\ with
an action level of 25 [micro]g/m\3\ were found to be technologically
and economically feasible some time in the future (say, in five years),
but not feasible immediately. In that case, OSHA might issue a final
rule with a PEL of 50 [micro]g/m\3\ and an action level of 25 [micro]g/
m\3\ to take effect in five years, but at the same time issue an
interim PEL of 100 [micro]g/m\3\ and an action level of 50 [micro]g/
m\3\ to be in effect until the final rule becomes feasible. Under this
regulatory alternative, and consistent with the public participation
and ``look back'' provisions of Executive Order 13563, the Agency could
monitor compliance with the interim standard, review progress toward
meeting the feasibility requirements of the final rule, and evaluate
whether any adjustments to the timing of the final rule would be
needed. Under Regulatory Alternative 9, the estimated costs
and benefits would be somewhere between those estimated for a PEL of
100 [micro]g/m\3\ with an action level of 50 [micro]g/m\3\ and those
estimated for a PEL of 50 [micro]g/m\3\ with an action level of 25
[micro]g/m\3\, the exact estimates depending on the length of time
until the final rule is phased in. OSHA emphasizes that this regulatory
alternative is contrary to the Agency's preliminary findings of
economic feasibility and, for the Agency to consider it, would require
specific evidence introduced on the record to show that the proposed
rule is not now feasible but would be feasible in the future.
    OSHA requests comments on these regulatory alternatives, including
the Agency's choice of regulatory alternatives (and whether there are
other regulatory alternatives the Agency should consider) and the
Agency's analysis of them.

I. Issues

    OSHA requests comment on all relevant issues, including health
effects, risk assessment, significance of risk, technological and
economic feasibility, and the provisions of the proposed regulatory
text. In addition, OSHA requests comments on all of the issues raised
by the Small Business Regulatory Fairness Enforcement Act (SBREFA)
Panel, as summarized in Table VIII-H-4 in Section VIII.H of this
preamble.
    OSHA is including Section I on issues at the beginning of the
document to assist readers as they review the proposal and consider any
comments they may want to submit. However, to fully understand the
questions in this section and provide substantive input in response to
them, the parts of the preamble that address these issues in detail
should be read and reviewed. These include: Section V, Health Effects
Summary; Section VI, Summary of the Preliminary Quantitative Risk
Assessment; Section VII, Significance of Risk; Section VIII, Summary of
the Preliminary Economic Analysis and Initial Regulatory Flexibility
Analysis; and Section XVI, Summary and Explanation of the Standards. In
addition, OSHA invites comment on additional technical questions and
discussions of economic issues presented in the Preliminary Economic
Analysis (PEA) of the proposed standards. Section XIX is the text of
the standards and is the final authority on what is required in them.
    OSHA requests that comments be organized, to the extent possible,
around the following issues and numbered questions. Comment on
particular provisions should contain a heading setting forth the
section and the paragraph in the standard that the comment is
addressing. Comments addressing more than one section or paragraph will
have correspondingly more headings.
    Submitting comments in an organized manner and with clear reference
to the issue raised will enable all participants

to easily see what issues the commenter addressed and how they were
addressed. This is particularly important in a rulemaking such as
silica, which has multiple adverse health effects and affects many
diverse processes and industries. Many commenters, especially small
businesses, are likely to confine their interest (and comments) to the
issues that affect them, and they will benefit from being able to
quickly identify comments on these issues in others' submissions. Of
course, the Agency welcomes comments concerning this proposal that fall
outside the issues raised in this section. However, OSHA is especially
interested in responses, supported by evidence and reasons, to the
following questions:

Health Effects

    1. OSHA has described a variety of studies addressing the major
adverse health effects that have been associated with exposure to
respirable crystalline silica. Has OSHA adequately identified and
documented all critical health impairments associated with occupational
exposure to respirable crystalline silica? If not, what adverse health
effects should be added? Are there any additional studies, other data,
or information that would affect the information discussed or
significantly change the determination of material health impairment?
Submit any relevant information, data, or additional studies (or the
citations), and explain your reasoning for recommending the inclusion
of any studies you suggest.
    2. Using currently available epidemiologic and experimental
studies, OSHA has made a preliminary determination that respirable
crystalline silica presents risks of lung cancer, silicosis, and non-
malignant respiratory disease (NMRD) as well as autoimmune and renal
disease risks to exposed workers. Is this determination correct? Are
there additional studies or other data OSHA should consider in
evaluating any of these adverse health risks? If so, submit the studies
(or citations) and other data and include your reasons for finding them
germane to determining adverse health effects of exposure to
crystalline silica.

Risk Assessment

    3. OSHA has relied upon risk models using cumulative respirable
crystalline silica exposure to estimate the lifetime risk of death from
occupational lung cancer, silicosis, and NMRD among exposed workers.
Additionally, OSHA has estimated the lifetime risk of silicosis
morbidity among exposed workers. Is cumulative exposure the correct
metric for exposure for each of these models? If not, what exposure
measure should be used?
    4. Some of the literature OSHA reviewed indicated that the risk of
contracting accelerated silicosis and lung cancer may be non-linear at
very high exposures and may be described by an exposure dose rate
health effect model. OSHA used the more conservative model of
cumulative exposure that is more protective to the worker. Are there
additional data to support or rebut any of these models used by OSHA?
Are there other models that OSHA should consider for estimating lung
cancer, silicosis, or NMRD risk? If so, describe the models and the
rationale for their use.
    5. Are there additional studies or sources of data that OSHA should
have included in its qualitative and quantitative risk assessments?
What are these studies and have they been peer-reviewed, or are they
soon to be peer-reviewed? What is the rationale for recommending the
studies or data?
    6. Steenland et al. (2001a) pooled data from 10 cohort studies to
conduct an analysis of lung cancer mortality among silica-exposed
workers. Can you provide quantitative lung cancer risk estimates from
other data sources? Have or will the data you submit be peer-reviewed?
OSHA is particularly interested in quantitative risk analyses that can
be conducted using the industrial sand worker studies by McDonald,
Hughes, and Rando (2001) and the pooled center-based case-control study
conducted by Cassidy et al. (2007).
    7. OSHA has made a preliminary determination that the available
data are not sufficient or suitable for quantitative analysis of the
risk of autoimmune disease, stomach cancer, and other cancer and non-
cancer health effects. Do you have, or are you aware of, studies, data,
and rationale that would be suitable for a quantitative risk assessment
for these adverse health effects? Submit the studies (or citations),
data, and rationale.

Profile of Affected Industries

    8. In its PEA of the proposed rule, summarized in Section VIII of
this preamble, OSHA presents a profile of the affected worker
population. The profile includes estimates of the number of affected
workers by industry sector or operation and job category, and the
distribution of exposures by job category. If your company has
potential worker exposures to respirable crystalline silica, is your
industry among those listed by North American Industry Classification
System (NAICS) code as affected industries? Are there additional data
that will enable the Agency to refine its profile of the worker
population exposed to respirable crystalline silica? If so, provide or
reference such data and explain how OSHA should use these data to
revise the profile.

Technological and Economic Feasibility of the Proposed PEL

    9. What are the job categories in which employees are potentially
exposed to respirable crystalline silica in your company or industry?
For each job category, provide a brief description of the operation and
describe the job activities that may lead to respirable crystalline
silica exposure. How many employees are exposed, or have the potential
for exposure, to respirable crystalline silica in each job category in
your company or industry? What are the frequency, duration, and levels
of exposures to respirable crystalline silica in each job category in
your company or industry? Where responders are able to provide exposure
data, OSHA requests that, where available, exposure data be personal
samples with clear descriptions of the length of the sample, analytical
method, and controls in place. Exposure data that provide information
concerning the controls in place are more valuable than exposure data
without such information.
    10. Please describe work environments or processes that may expose
workers to cristobalite. Please provide supporting evidence, or explain
the basis of your knowledge.
    11. Have there been technological changes within your industry that
have influenced the magnitude, frequency, or duration of exposure to
respirable crystalline silica or the means by which employers attempt
to control such exposures? Describe in detail these technological
changes and their effects on respirable crystalline silica exposures
and methods of control.
    12. Has there been a trend within your industry or an effort in
your firm to reduce or eliminate respirable crystalline silica from
production processes, products, and services? If so, please describe
the methods used and provide an estimate of the percentage reduction in
respirable crystalline silica, and the extent to which respirable
crystalline silica is still necessary in specific processes within
product lines or production activities. If you have substituted another
substance(s) for crystalline silica, identify the substance(s) and any
adverse health effects associated with exposure to the substitute
substances, and the cost impact of substitution (cost of materials,
productivity impact). OSHA also

requests that responders describe any health hazards or technical,
economic, or other deterrents to substitution.
    13. Has your industry or firm used outsourcing or subcontracting,
or concentrated high exposure tasks in-house, in order to expose fewer
workers to respirable crystalline silica? An example would be
subcontracting for the removal of hardened concrete from concrete
mixing trucks, a task done typically 2-4 times a year, to a specialty
subcontractor. What methods have you used to reduce the number of
workers exposed to respirable crystalline silica and how were they
implemented? Describe any trends related to concentration of high
exposure tasks and provide any supporting information.
    14. Does any job category or employee in your workplace have
exposures to respirable crystalline silica that air monitoring data do
not adequately portray due to the short duration, intermittent or non-
routine nature, or other unique characteristics of the exposure?
Explain your response and indicate peak levels, duration, and frequency
of exposures for employees in these job categories.
    15. OSHA requests the following information regarding engineering
and work practice controls to control exposure to crystalline silica in
your workplace or industry:
    a. Describe the operations and tasks in which the proposed PEL is
being achieved most of the time by means of engineering and work
practice controls.
    b. What engineering and work practice controls have been
implemented in these operations and tasks?
    c. For all operations and tasks in facilities where respirable
crystalline silica is used, what engineering and work practice controls
have been implemented to control respirable crystalline silica? If you
have installed engineering controls or adopted work practices to reduce
exposure to respirable crystalline silica, describe the exposure
reduction achieved and the cost of these controls.
    d. Where current work practices include the use of regulated areas
and hygiene facilities, provide data on the implementation of these
controls, including data on the costs of installation, operation, and
maintenance associated with these controls.
    e. Describe additional engineering and work practice controls that
could be implemented in each operation where exposure levels are
currently above the proposed PEL to further reduce exposure levels.
    f. When these additional controls are implemented, to what levels
can exposure be expected to be reduced, or what percent reduction is
expected to be achieved?
    g. What amount of time is needed to develop, install, and implement
these additional controls? Will the added controls affect productivity?
If so, how?
    h. Are there any processes or operations for which it is not
reasonably possible to implement engineering and work practice controls
within one year to achieve the proposed PEL? If so, how much additional
time would be necessary?
    16. OSHA requests information on whether there are any specific
conditions or job tasks involving exposure to respirable crystalline
silica where engineering and work practice controls are not available
or are not capable of reducing exposure levels to or below the proposed
PEL most of the time. Provide data and evidence to support your
response.
    17. OSHA has made a preliminary determination that compliance with
the proposed PEL can be achieved in most operations most of the time
through the use of engineering and work practice controls. OSHA has
further made a preliminary determination that the proposed rule is
technologically feasible. OSHA solicits comments on the reasonableness
of these preliminary determinations.

Compliance Costs

    18. In its PEA (summarized in Section VIII.3 of this preamble),
OSHA developed its estimate of the costs of the proposed rule. The
Agency requests comment on the methodological and analytical
assumptions applied in the cost analysis. Of particular importance are
the unit cost estimates provided in tables and text in Chapter V of the
PEA for all major provisions of the proposed rule. OSHA requests the
following information regarding unit and total compliance costs:
    a. If you have installed engineering controls or adopted work
practices to reduce exposure to respirable crystalline silica, describe
these controls and their costs. If you have substituted another
substance(s) for crystalline silica, what has been the cost impact of
substitution (cost of materials, productivity impact)?
    b. OSHA has proposed to limit the prohibition on dry sweeping to
situations where this activity could contribute to exposure that
exceeds the PEL and estimated the costs for the use of wet methods to
control dust. OSHA requests comment on the use of wet methods as a
substitute for dry sweeping and whether the prohibition on dry sweeping
is feasible and cost-effective.
    c. In its PEA, OSHA presents estimated baseline levels of use of
personal protective equipment (PPE) and the incremental PPE costs
associated with the proposed rule. Are OSHA's estimated PPE compliance
rates reasonable? Are OSHA's estimates of PPE costs, and the
assumptions underlying these estimates, consistent with current
industry practice? If not, provide data and evidence describing current
industry PPE practices.
    d. Do you currently conduct exposure monitoring for respirable
crystalline silica? Are OSHA's estimates of exposure assessment costs
reasonable? Would your company require outside consultants to perform
exposure monitoring?
    e. Are OSHA's estimates for medical surveillance costs--including
direct medical costs, the opportunity cost of worker time for offsite
travel and for the health screening, and recordkeeping costs--
reasonable?
    f. In its PEA, OSHA presents estimated baseline levels of training
and information concerning respirable crystalline silica-related
hazards and the incremental costs associated with the additional
requirements for training and information in the proposed rule. OSHA
requests information on information and training programs addressing
respirable crystalline silica that are currently being implemented by
employers and any necessary additions to those programs that are
anticipated in response to the proposed rule. Are OSHA's baseline
estimates and unit costs for training reasonable and consistent with
current industry practice?
    g. Are OSHA's estimated costs for regulated areas and written
access control plans reasonable?
    h. The cost estimates in the PEA take the much higher labor
turnover rates in construction into account when calculating costs. For
the proposed rule, OSHA used the most recent BLS turnover rate of 64
percent for construction (versus a turnover rate of 27.2 percent for
general industry). OSHA believes that the estimates in the PEA capture
the effect of high turnover rates in construction and solicits comments
on this issue.
    i. Has OSHA omitted any costs that would be incurred to comply with
the proposed rule?

Effects on Small Entities

    19. OSHA has considered the effects on small entities raised during
its SBREFA process and addressed these concerns in Chapter VIII of the
PEA. Are there additional difficulties small

entities may encounter when attempting to comply with requirements of
the proposed rule? Can any of the proposal's requirements be deleted or
simplified for small entities, while still providing equivalent
protection of the health of employees? Would allowing additional time
for small entities to comply make a difference in their ability to
comply? How much additional time would be necessary?

Economic Impacts

    20. OSHA, in its PEA, has estimated compliance costs per affected
entity and the likely impacts on revenues and profits. OSHA requests
that affected employers provide comment on OSHA's estimate of revenue,
profit, and the impacts of costs for their industry or application
group. The Agency also requests that employers provide data on their
revenues, profits, and the impacts of cost, if available. Are there
special circumstances--such as unique cost factors, foreign
competition, or pricing constraints--that OSHA needs to consider when
evaluating economic impacts for particular applications and industry
groups?
    21. OSHA seeks comment as to whether establishments will be able to
finance first-year compliance costs from cash flow, and under what
circumstances a phase-in approach will assist firms in complying with
the proposed rule.
    22. The Agency invites comment on potential employment impacts of
the proposed silica rule, and on Inforum's estimates of the employment
impacts of the proposed silica rule on the U.S. economy.

Outreach and Compliance Assistance

    23. If the proposed rule is promulgated, OSHA will provide outreach
materials on the provisions of the standards in order to encourage and
assist employers in complying. Are there particular materials that
would make compliance easier for your company or industry? What
materials would be especially useful for small entities? Submit
recommendations or samples.

Benefits and Net Benefits

    24. OSHA requests comments on any aspect of its estimation of
benefits and net benefits from the proposed rule, including the
following:
    a. The use of willingness-to-pay measures and estimates based on
compensating wage differentials.
    b. The data and methods used in the benefits calculations.
    c. The choice of discount rate for annualizing the monetized
benefits of the proposed rule.
    d. Increasing the monetary value of a statistical life over time
resulting from an increase in real per capita income and the estimated
income elasticity of the value of life.
    e. Extending the benefits analysis beyond the 60-year period used
in the PEA.
    f. The magnitude of non-quantified health benefits arising from the
proposed rule and methods for better measuring these effects. An
example would be diagnosing latent tuberculosis (TB) in the silica-
exposed population and thereby reducing the risk of TB being spread to
the population at large.

Overlapping and Duplicative Regulations

    25. Do any federal regulations duplicate, overlap, or conflict with
the proposed respirable crystalline silica rule? If so, provide or cite
to these regulations.

Alternatives/Ways to Simplify a New Standard

    26. Comment on the alternative to new comprehensive standards
(which have ancillary provisions in addition to a permissible exposure
limit) that would be simply improved outreach and enforcement of the
existing standards (which is only a permissible exposure limit with no
ancillary provisions). Do you believe that improved outreach and
enforcement of the existing permissible exposure limits would be
sufficient to reduce significant risks of material health impairment in
workers exposed to respirable crystalline silica? Provide information
to support your position.
    27. OSHA solicits comments on ways to simplify the proposed rule
without compromising worker protection from exposure to respirable
crystalline silica. In particular, provide detailed recommendations on
ways to simplify the proposed standard for construction. Provide
evidence that your recommended simplifications would result in a
standard that was effective, to the extent feasible, in reducing
significant risks of material health impairment in workers exposed to
respirable crystalline silica.

Environmental Impacts

    28. Submit data, information, or comments pertaining to possible
environmental impacts of adopting this proposal, including any positive
or negative environmental effects and any irreversible commitments of
natural resources that would be involved. In particular, consideration
should be given to the potential direct or indirect impacts of the
proposal on water and air pollution, energy use, solid waste disposal,
or land use. Would compliance with the silica rule require additional
actions to comply with federal, state, or local environmental
requirements?
    29. Some small entity representatives advised OSHA that the use of
water as a control measure is limited at their work sites due to
potential water and soil contamination. OSHA believes these limits may
only apply in situations where crystalline silica is found with other
toxic substances such as during abrasive blasting of metal or painted
metal structures, or in locations where state and local requirements
are more restrictive than EPA requirements. OSHA seeks comments on this
issue, including cites to applicable requirements.
    a. Are there limits on the use of water controls in your operations
due to environmental regulations? If so, are the limits due to the non-
silica components of the waste stream? What are these non-silica
components?
    b. What metals or other toxic chemicals are in your silica waste
streams and what are the procedures and costs to filter out these
metals or other toxic chemicals from your waste streams? Provide
documentation to support your cost estimates.

Provisions of the Standards

Scope

    30. OSHA's Advisory Committee on Construction Safety and Health
(ACCSH) has historically advised the Agency to take into consideration
the unique nature of construction work environments by either setting
separate standards or making accommodations for the differences in work
environments in construction as compared to general industry. ASTM, for
example, has separate silica standards of practice for general industry
and construction, E 1132-06 and E 2625-09, respectively. To account for
differences in the workplace environments for these different sectors,
OSHA has proposed separate standards for general industry/maritime and
construction. Is this approach necessary and appropriate? What other
approaches, if any, should the Agency consider? Provide a rationale for
your response.
    31. OSHA has proposed that the scope of the construction standard
include all occupational exposures to respirable crystalline silica in
construction work as defined in 29 CFR 1910.12(b) and covered under 29
CFR part 1926, rather

than restricting the application of the rule to specific construction
operations. Should OSHA modify the scope to limit what is covered? What
should be included and what should be excluded? Provide a rationale for
your position. Submit your proposed language for the scope and
application provision.
    32. OSHA has not proposed to cover agriculture because the Agency
does not have data sufficient to determine the feasibility of the
proposed PEL in agricultural operations. Should OSHA cover respirable
crystalline silica exposure in agriculture? Provide evidence to support
your position. OSHA seeks information on agricultural operations that
involve respirable crystalline silica exposures, including information
that identifies particular activities or crops (e.g., hand picking
fruit and vegetables, shaking branches and trees, harvesting with
combines, loading storage silos, planting) associated with exposure,
information indicating levels of exposure, and information relating to
available control measures and their effectiveness. OSHA also seeks
information related to the development of respirable crystalline
silica-related adverse health effects and diseases among workers in the
agricultural sector.
    33. Should OSHA limit coverage of the rule to materials that
contain a threshold concentration (e.g., 1%) of crystalline silica? For
example, OSHA's Asbestos standard defines ``asbestos-containing
material'' as any material containing more than 1% asbestos, for
consistency with EPA regulations. OSHA has not proposed a comparable
limitation to the definition of respirable crystalline silica. Is this
approach appropriate? Provide the rationale for your position.
    34. OSHA has proposed to cover shipyards under the general industry
standard. Are there any unique circumstances in shipyard employment
that would justify development of different provisions or a separate
standard for the shipyard industry? What are the circumstances and how
would they not be adequately covered by the general industry standard?

Definitions

    35. Competent person. OSHA has proposed limited duties for a
competent person relating to establishment of an access control plan.
The Agency did not propose specific requirements for training of a
competent person. Is this approach appropriate? Should OSHA include a
competent person provision? If so, should the Agency add to, modify, or
delete any of the duties of a competent person as described in the
proposed standard? Provide the basis for your recommendations.
    36. Has OSHA defined ``respirable crystalline silica''
appropriately? If not, provide the definition that you believe is
appropriate. Explain the basis for your response, and provide any data
that you believe are relevant.
    37. The proposed rule defines ``respirable crystalline silica'' in
part as ``airborne particles that contain quartz, cristobalite, and/or
tridymite.'' OSHA believes that tridymite is rarely found in nature or
in the workplace. Please describe any instances of occupational
exposure to tridymite of which you are aware. Please provide supporting
evidence, or explain the basis of your knowledge. Should tridymite be
included in the scope of this proposed rule? Please provide any
evidence to support your position.

PEL and Action Level

    38. OSHA has proposed a TWA PEL for respirable crystalline silica
of 50 [micro]g/m\3\ for general industry, maritime, and construction.
The Agency has made a preliminary determination that this is the lowest
level that is technologically feasible. The Agency has also determined
that a PEL of 50 [micro]g/m\3\ will substantially reduce, but not
eliminate, significant risk of material health impairment. Is this PEL
appropriate, given the Agency's obligation to reduce significant risk
of material health impairment to the extent feasible? If not, what PEL
would be more appropriate? The Agency also solicits comment on
maintaining the existing PELs for respirable crystalline silica.
Provide evidence to support your response.
    39. OSHA has proposed a single PEL for respirable crystalline
silica (quartz, cristobalite, and tridymite). Is a single PEL
appropriate, or should the Agency maintain separate PELs for the
different forms of respirable crystalline silica? Provide the rationale
for your position.
    40. OSHA has proposed an action level for respirable crystalline
silica exposure of 25 [micro]g/m\3\ in general industry, maritime, and
construction. Is this an appropriate approach and level, and if not,
what approach or level would be more appropriate and why? Should an
action level be included in the final rule? Provide the rationale for
your position.
    41. If an action level is included in the final rule, which
provisions, if any, should be triggered by exposure above or below the
action level? Provide the basis for your position and include
supporting information.
    42. If no action level is included in the final rule, which
provisions should apply to all workers exposed to respirable
crystalline silica? Which provisions should be triggered by the PEL?
Are there any other appropriate triggers for the requirements of the
rule?

Exposure Assessment

    43. OSHA is proposing to allow employers to initially assess
employee exposures using air monitoring or objective data. Has OSHA
defined ``objective data'' sufficiently for an employer to know what
data may be used? If not, submit an alternative definition. Is it
appropriate to allow employers to use objective data to perform
exposure assessments? Explain why or why not.
    44. The proposed rule provides two options for periodic exposure
assessment: (1) A fixed schedule option, and (2) a performance option.
The performance option provides employers flexibility in the methods
used to determine employee exposures, but requires employers to
accurately characterize employee exposures. The proposed approach is
explained in the Summary and Explanation for paragraph (d) Exposure
Assessment. OSHA solicits comments on this proposed exposure assessment
provision. Is the wording of the performance option in the regulatory
text understandable and does it clearly indicate what would constitute
compliance with the provision? If not, suggest alternative language
that would clarify the provision, enabling employers to more easily
understand what would constitute compliance.
    45. Do you conduct initial air monitoring or do you rely on
objective data to determine respirable crystalline silica exposures? If
objective data, what data do you use? Have you conducted historical
exposure monitoring of your workforce that is representative of current
process technology and equipment use? Describe any other approaches you
have implemented for assessing an employee's initial exposure to
respirable crystalline silica.
    46. OSHA is proposing specific requirements for laboratories that
perform analyses of respirable crystalline silica samples. The
rationale is to improve the precision in individual laboratories and
reduce the variability of results between laboratories, so that
sampling results will be more reliable. Are these proposed requirements
appropriate? Will the laboratory requirements add necessary reliability
and reduce inter-lab variability, or might they be overly proscriptive?
Provide the basis for your response.
    47. Has OSHA correctly described the accuracy and precision of
existing methods of sampling and analysis for

respirable crystalline silica at the proposed action level and PEL? Can
worker exposures be accurately measured at the proposed action level
and PEL? Explain the basis for your response, and provide any data that
you believe are relevant.
    48. OSHA has not addressed the performance of the analytical method
with respect to tridymite since we have found little available data.
Please comment on the performance of the analytical method with respect
to tridymite and provide any data to support your position.

Regulated Areas and Access Control

    49. Where exposures exceed the PEL, OSHA has proposed to provide
employers with the option of either establishing a regulated area or
establishing a written access control plan. For which types of work
operations would employers be likely to establish a written access
control plan? Will employees be protected by these options? Provide the
basis for your position and include supporting information.
    50. The Summary and Explanation for paragraph (e) Regulated Areas
and Access Control clarifies how the regulated area requirements would
apply to multi-employer worksites in the proposed standard. OSHA
solicits comments on this issue.
    51. OSHA is proposing limited requirements for protective clothing
in the silica rule. Is this appropriate? Are you aware of any
situations where more or different protective clothing would be needed
for silica exposures? If so, what type of protective clothing and
equipment should be required? Are there additional provisions related
to protective clothing that should be incorporated into this rule that
will enhance worker protection? Provide the rationale and data that
support your conclusions.

Methods of Compliance

    52. In OSHA's cadmium standard (29 CFR 1910.1027(f)(1)(ii),(iii),
and (iv)), the Agency established separate engineering control air
limits (SECALs) for certain processes in selected industries. SECALs
were established where compliance with the PEL by means of engineering
and work practice controls was infeasible. For these industries, a
SECAL was established at the lowest feasible level that could be
achieved by engineering and work practice controls. The PEL was set at
a lower level, and could be achieved by any allowable combination of
controls, including respiratory protection. In OSHA's chromium (VI)
standard (29 CFR 1910.1026), an exception similar to SECALs was made
for painting airplanes and airplane parts. Should OSHA follow this
approach for respirable crystalline silica in any industries or
processes? If so, in what industries or processes, and at what exposure
levels, should the SECALs be established? Provide the basis for your
position and include supporting information.
    53. The proposed standards do not contain a requirement for a
written exposure control program. The two ASTM standards for general
industry and construction (E 1132-06, section 4.2.6, and E 2626-09,
section 4.2.5) state that, where overexposures are persistent (such as
in regulated areas or abrasive blasting operations), a written exposure
control plan shall establish engineering and administrative controls to
bring the area into compliance, if feasible. In addition, the proposed
regulatory language developed by the Building and Construction Trades
Department, AFL-CIO contains provisions for a written program. The ASTM
standards recommend that, where there are regulated areas with
persistent exposures or tasks, tools, or operations that tend to cause
respirable crystalline silica exposure, the employer will conduct a
formal analysis and implement a written control plan (an abatement
plan) on how to bring the process into compliance. If that is not
feasible, the employer is to indicate the respiratory protection and
other protective procedures that will be used to protect employee(s)
permanently or until compliance will be achieved. Should OSHA require
employers to develop and implement a written exposure control plan and,
if so, what should be required to be in the plans?
    54. Table 1 in the proposed construction standard specifies
engineering and work practice controls and respiratory protection for
selected construction operations, and exempts employers who implement
these controls from exposure assessment requirements. Is this approach
appropriate? Are there other operations that should be included, or
listed operations that should not be included? Are the specified
control measures effective? Should any other changes be made in Table
1? How should OSHA update Table 1 in the future to account for
development of new technologies? Provide data and information to
support your position.
    55. OSHA requests comments on the degree of specificity used for
the engineering and work practice controls for tasks identified in
Table 1, including maintenance requirements. Should OSHA require an
evaluation or inspection checklist for controls? If so, how frequently
should evaluations or inspections be conducted? Provide any examples of
such checklists, along with information regarding their frequency of
use and effectiveness.
    56. In the proposed construction standard, when employees perform
an operation listed in Table 1 and the employer fully implements the
engineering controls, work practices, and respiratory protection
described in Table 1 for that operation, the employer is not required
to assess the exposure of the employees performing such operations.
However, the employer must still ensure compliance with the proposed
PEL for that operation. OSHA seeks comment on whether employers fully
complying with Table 1 for an operation should still need to comply
with the proposed PEL for that operation. Instead, should OSHA treat
compliance with Table 1 as automatically meeting the requirements of
the proposed PEL?
    57. Are the descriptions of the operations (specific task or tool
descriptions) and control technologies in Table 1 clear and precise
enough so that employers and workers will know what controls they
should be using for the listed operations? Identify the specific
operation you are addressing and whether your assessment is based on
your anecdotal experience or research. For each operation, are the data
and other supporting information sufficient to predict the range of
expected exposures under the controlled conditions? Identify
operations, if any, where you believe the data are not sufficient.
Provide the reasoning and data that support your position.
    58. In one specific example from Table 1, OSHA has proposed the
option of using a wet method for hand-operated grinders, with
respirators required only for operations lasting four hours or more.
Please comment and provide OSHA with additional information regarding
wet grinding and the adequacy of this control strategy. OSHA is also
seeking additional information on the second option (commercially
available shrouds and dust collection systems) to confirm that this
control strategy (including the use of half-mask respirators) will
reduce workers' exposure to or below the PEL.
    59. For impact drilling operations lasting four hours or less, OSHA
is proposing in Table 1 to allow workers to use water delivery systems
without the use of respiratory protection, as the Agency believes that
this dust suppression method alone will provide

consistent, sufficient protection. Is this control strategy
appropriate? Please provide the basis for your position and any
supporting evidence or additional information that addresses the
appropriateness of this control strategy.
    60. In the case of rock drilling, in order to ensure that workers
are adequately protected from the higher exposures that they would
experience working under shrouds, OSHA is proposing in Table 1 that
employers ensure that workers use half-mask respirators when working
under shrouds at the point of operation. Is this specification
appropriate? Please provide the basis for your position and any
supporting evidence or additional information that addresses the
appropriateness of this specification.
    61. OSHA has specified a control strategy for concrete drilling in
Table 1 that includes use of a dust collection system as well as a low-
flow water spray. Please provide to OSHA any data that you have that
describes the efficacy of these controls. Is the control strategy in
Table 1 adequate? Please provide the basis for your position and any
supporting evidence or additional information regarding the adequacy of
this control strategy.
    62. One of the control options in Table 1 in the proposed
construction standard for rock-crushing operations is local exhaust
ventilation. However, OSHA is aware of difficulties in applying this
control to this operation. Is this control strategy appropriate and
practical for rock-crushing operations? Please provide any information
that you have addressing this issue.
    63. OSHA has not proposed to prohibit the use of crystalline silica
as an abrasive blasting agent. Abrasive blasting, similar to other
operations that involve respirable crystalline silica exposures, must
follow the hierarchy of controls, which means, if feasible, that
substitution, engineering, or administrative controls or a combination
of these controls must be used to minimize or eliminate the exposure
hazard. Is this approach appropriate? Provide the basis for your
position and any supporting evidence.
    64. The technological feasibility study (PEA, Chapter 4) indicates
that employers use substitutes for crystalline silica in a variety of
operations. If you are aware of substitutes for crystalline silica that
are currently being used in any operation not considered in the
feasibility study, please provide to OSHA relevant information that
contains data supporting the effectiveness, in reducing exposure to
crystalline silica, of those substitutes. Provide any information you
may have on the health hazards associated with exposure to these
substitutes.
    65. Information regarding the effectiveness of dust control kits
that incorporate local exhaust ventilation in the railroad
transportation industry in reducing worker exposure to crystalline
silica is not available from the manufacturer. If you have any relevant
information on the effectiveness of such kits, please provide it to
OSHA.
    66. The proposed rule prohibits the use of compressed air and dry
brushing and sweeping for cleaning of surfaces and clothing in general
industry, maritime, and construction and promotes the use of wet
methods and HEPA-filter vacuuming as alternatives. Are there any
circumstances in general industry, maritime, or construction work where
dry sweeping is the only kind of sweeping that can be done? Have you
done dry sweeping and, if so, what has been your experience with it?
What methods have you used to minimize dust when dry sweeping? Can
exposure levels be kept below the proposed PEL when dry sweeping is
conducted? How? Provide exposure data for periods when you conducted
dry sweeping. If silica respirable dust samples are not available,
provide real time respirable dust or gravimetric respirable dust data.
Is water available at most sites to wet down dust prior to sweeping?
How effective is the use of water? Does the use of water cause other
problems for the worksite? Are there other substitutes that are
effective?
    67. A 30-day exemption from the requirement to implement
engineering and work practice controls was not included in the proposed
standard for construction, and has been removed from the proposed
standard for general industry and maritime. OSHA requests comment on
this issue.
    68. The proposed prohibition on employee rotation is explained in
the Summary and Explanation for paragraph (f) Methods of Compliance.
OSHA solicits comment on the prohibition of employee rotation to
achieve compliance when exposure levels exceed the PEL.

Medical Surveillance

    69. Is medical surveillance being provided for respirable
crystalline silica-exposed employees at your worksite? If so:
    a. How do you determine which employees receive medical
surveillance (e.g., by exposure level or other factors)?
    b. Who administers and implements the medical surveillance (e.g.,
company doctor or nurse, outside doctor or nurse)?
    c. What examinations, tests, or evaluations are included in the
medical surveillance program? Does your medical surveillance program
include testing for latent TB? Do you include pulmonary function
testing in your medical surveillance program?
    d. What benefits (e.g., health, reduction in absenteeism, or
financial) have been achieved from the medical surveillance program?
    e. What are the costs of your medical surveillance program? How do
your costs compare with OSHA's estimated unit costs for the physical
examination and employee time involved in the medical surveillance
program? Are OSHA's baseline assumptions and cost estimates for medical
surveillance consistent with your experiences providing medical
surveillance to your employees?
    f. How many employees are included in your medical surveillance
program?
    g. What NAICS code describes your workplace?
    70. Is the content and frequency of proposed examinations
appropriate? If not, how should content and frequency be modified?
    71. Is the specified content of the physician or other licensed
health care professional's (PLHCP) written medical opinion sufficiently
detailed to enable the employer to address the employee's needs and
potential workplace improvements, and yet appropriately limited so as
to protect the employee's medical privacy? If not, how could the
medical opinion be improved?
    72. Is the requirement for latent TB testing appropriate? Does the
proposed rule implement this requirement in a cost-effective manner?
Provide the data or cite references that support your position.
    73. Is the requirement for pulmonary function testing initially and
at three-year intervals appropriate? Is there an alternate strategy or
schedule for conducting follow-up testing that is better? Provide data
or cite references to support your position.
    74. Is the requirement for chest X-rays initially and at three-year
intervals appropriate? Is there an alternate strategy or schedule for
conducting follow-up chest X-rays that you believe would be better?
Provide data or cite references to support your position.
    75. Are there other tests that should be included in medical
surveillance?
    76. Do you provide medical surveillance to employees under another
OSHA standard or as a matter of company policy? If so, describe your
program in terms of what standards the program addresses and such
factors as content and frequency of examinations

and referrals, and reports to the employer.
    77. Is exposure for 30 days at or above the PEL the appropriate
number of days to trigger medical surveillance? Should the appropriate
reference for medical monitoring be the PEL or the action level? Is 30
days from initial assignment a reasonable amount of time to provide a
medical exam? Indicate the basis for your position.
    78. Are PLHCPs available in your geographic area to provide medical
surveillance to workers who are covered by the proposed rule? For
example, do you have access to qualified X-ray technicians, NIOSH-
certified B-readers, and pulmonary specialists? Describe any
difficulties you may have with regard to access to PLHCPs to provide
surveillance for the rule. Note what you consider your ``geographic
area'' in responding to this question.
    79. OSHA is proposing to allow an ``equivalent diagnostic study''
in place of requirements to use a chest X-ray (posterior/anterior view;
no less than 14 x 17 inches and no more than 16 x 17 inches at full
inspiration; interpreted and classified according to the International
Labour Organization (ILO) International Classification of Radiographs
of Pneumoconioses by a NIOSH-certified ``B'' reader). Two other
radiological test methods, computed tomography (CT) and high resolution
computed tomography (HRCT), could be considered ``equivalent diagnostic
studies'' under paragraph (h)(2)(iii) of the proposal. However, the
benefits of CT or HRCT should be balanced with risks, including higher
radiation doses. Also, standardized methods for interpreting and
reporting results of CT or HRCT are not currently available. The Agency
requests comment on whether CT and HRCT should be considered
``equivalent diagnostic studies'' under the rule. Provide a rationale
and evidence to support your position.
    80. OSHA has not included requirements for medical removal
protection (MRP) in the proposed rule, because OSHA has made a
preliminary determination that there are few instances where temporary
worker removal and MRP will be useful. The Agency requests comment as
to whether the respirable crystalline silica rule should include
provisions for the temporary removal and extension of MRP benefits to
employees with certain respirable crystalline silica-related health
conditions. In particular, what medical conditions or findings should
trigger temporary removal and for what maximum amount of time should
MRP benefits be extended? OSHA also seeks information on whether or not
MRP is currently being used by employers with respirable crystalline
silica-exposed workers, and the costs of such programs.

Hazard Communication and Training

    81. OSHA has proposed that employers provide hazard information to
employees in accordance with the Agency's Hazard Communication standard
(29 CFR 1910.1200). Compliance with the Hazard Communication standard
would mean that there would be a requirement for a warning label for
substances that contain more than 0.1 percent crystalline silica.
Should this requirement be changed so that warning labels would only be
required of substances more than 1 percent by weight of silica? Provide
the rationale for your position. The Agency also has proposed
additional training specific to work with respirable crystalline
silica. Should OSHA include these additional requirements in the final
rule, or are the requirements of the Hazard Communication standard
sufficient?
    82. OSHA is providing an abbreviated training section in this
proposal as compared to ASTM consensus standards (see ASTM E 1132-06,
sections 4.8.1-5). The Hazard Communication standard is comprehensive
and covers most of the training requirements traditionally included in
an OSHA health standard. Do you concur with OSHA that performance-based
training specified in the Hazard Communication standard, supplemented
by the few training requirements of this section, is sufficient in its
scope and depth? Are there any other training provisions you would add?
    83. The proposed rule does not alter the requirements for
substances to have warning labels, specify wording for labels, or
otherwise modify the provisions of the OSHA's Hazard Communication
standard. OSHA invites comment on these issues.

Recordkeeping

    84. OSHA is proposing to require recordkeeping for air monitoring
data, objective data, and medical surveillance records. The proposed
rule's recordkeeping requirements are discussed in the Summary and
Explanation for paragraph (j) Recordkeeping. The Agency seeks comment
on the utility of these recordkeeping requirements as well as the costs
of making and maintaining these records. Provide evidence to support
your position.

Dates

    85. OSHA requests comment on the time allowed for compliance with
the provisions of the proposed rule. Is the time proposed appropriate,
or should there be a longer or shorter phase-in of requirements? In
particular, should requirements for engineering controls and/or medical
surveillance be phased in over a longer period of time (e.g., over 1,
2, 3, or more years)? Should an extended phase-in period be provided
for specific industries (e.g., industries where first-year or
annualized cost impacts are highest), specific size-classes of
employers (e.g., employers with fewer than 20 employees), combinations
of these factors, or all firms covered by the rule? Identify any
industries, processes, or operations that have special needs for
additional time, the additional time required, and the reasons for the
request.
    86. OSHA is proposing a two-year start-up period to allow
laboratories time to achieve compliance with the proposed requirements,
particularly with regard to requirements for accreditation and round
robin testing. OSHA also recognizes that requirements for monitoring in
the proposed rule will increase the required capacity for analysis of
respirable crystalline silica samples. Do you think that this start-up
period is enough time for laboratories to achieve compliance with the
proposed requirements and to develop sufficient analytic capacity? If
you think that additional time is needed, please tell OSHA how much
additional time is required and give your reasons for this request.

Appendices

    87. Some OSHA health standards include appendices that address
topics such as the hazards associated with the regulated substance,
health screening considerations, occupational disease questionnaires,
and PLHCP obligations. In this proposed rule, OSHA has included a non-
mandatory appendix to clarify the medical surveillance provisions of
the rule. What would be the advantages and disadvantages of including
such an appendix in the final rule? If you believe it should be
included, comment on the appropriateness of the information included.
What additional information, if any, should be included in the
appendix?

II. Pertinent Legal Authority

    The purpose of the Occupational Safety and Health Act, 29 U.S.C.
651 et seq. (``the Act''), is to ``. . . assure so far as possible
every working man and

woman in the nation safe and healthful working conditions and to
preserve our human resources.'' 29 U.S.C. 651(b).
    To achieve this goal Congress authorized the Secretary of Labor
(the Secretary) to promulgate and enforce occupational safety and
health standards. 29 U.S.C. 654(b) (requiring employers to comply with
OSHA standards), 655(a) (authorizing summary adoption of existing
consensus and federal standards within two years of the Act's
enactment), and 655(b) (authorizing promulgation, modification or
revocation of standards pursuant to notice and comment).
    The Act provides that in promulgating health standards dealing with
toxic materials or harmful physical agents, such as this proposed
standard regulating occupational exposure to respirable crystalline
silica, the Secretary, shall set the standard which most adequately
assures, to the extent feasible, on the basis of the best available
evidence that no employee will suffer material impairment of health or
functional capacity even if such employee has regular exposure to the
hazard dealt with by such standard for the period of his working life.
29 U.S.C. 655(b)(5).
    The Supreme Court has held that before the Secretary can promulgate
any permanent health or safety standard, she must make a threshold
finding that significant risk is present and that such risk can be
eliminated or lessened by a change in practices. Industrial Union
Dept., AFL-CIO v. American Petroleum Institute, 448 U.S. 607, 641-42
(1980) (plurality opinion) (``The Benzene case''). Thus, section
6(b)(5) of the Act requires health standards to reduce significant risk
to the extent feasible. Id.
    The Court further observed that what constitutes ``significant
risk'' is ``not a mathematical straitjacket'' and must be ``based
largely on policy considerations.'' The Benzene case, 448 U.S. at 655.
The Court gave the example that if,

. . . the odds are one in a billion that a person will die from
cancer . . . the risk clearly could not be considered significant.
On the other hand, if the odds are one in one thousand that regular
inhalation of gasoline vapors that are 2% benzene will be fatal, a
reasonable person might well consider the risk significant. [Id.]

    OSHA standards must be both technologically and economically
feasible. United Steelworkers v. Marshall, 647 F.2d 1189, 1264 (D.C.
Cir. 1980) (``The Lead I case''). The Supreme Court has defined
feasibility as ``capable of being done.'' Am. Textile Mfrs. Inst. v.
Donovan, 452 U.S. 490, 509-510 (1981) (``The Cotton Dust case''). The
courts have further clarified that a standard is technologically
feasible if OSHA proves a reasonable possibility,

. . . within the limits of the best available evidence . . . that
the typical firm will be able to develop and install engineering and
work practice controls that can meet the PEL in most of its
operations. [See The Lead I case, 647 F.2d at 1272]

    With respect to economic feasibility, the courts have held that a
standard is feasible if it does not threaten massive dislocation to or
imperil the existence of the industry. Id. at 1265. A court must
examine the cost of compliance with an OSHA standard,

. . . in relation to the financial health and profitability of the
industry and the likely effect of such costs on unit consumer prices
. . . [T]he practical question is whether the standard threatens the
competitive stability of an industry, . . . or whether any intra-
industry or inter-industry discrimination in the standard might
wreck such stability or lead to undue concentration. [Id. (citing
Indus. Union Dep't, AFL-CIO v. Hodgson, 499 F.2d 467 (D.C. Cir.
1974))]

    The courts have further observed that granting companies reasonable
time to comply with new PELs may enhance economic feasibility. The Lead
I case at 1265. While a standard must be economically feasible, the
Supreme Court has held that a cost-benefit analysis of health standards
is not required by the Act because a feasibility analysis is required.
The Cotton Dust case, 453 U.S. at 509.
    Finally, sections 6(b)(7) and 8(c) of the Act authorize OSHA to
include among a standard's requirements labeling, monitoring, medical
testing, and other information-gathering and -transmittal provisions.
29 U.S.C. 655(b)(7), 657(c).

III. Events Leading to the Proposed Standards

    OSHA's current standards for workplace exposure to respirable
crystalline silica were adopted in 1971, pursuant to section 6(a) of
the OSH Act (36 FR 10466, May 29, 1971). Section 6(a) provided that in
the first two years after the effective date of the Act, OSHA had to
promulgate ``start-up'' standards, on an expedited basis and without
public hearing or comment, based on national consensus or established
Federal standards that improved employee safety or health. Pursuant to
that authority, OSHA in 1971 promulgated approximately 425 permissible
exposure limits (PELs) for air contaminants, including silica, derived
principally from Federal standards applicable to government contractors
under the Walsh-Healey Public Contracts Act, 41 U.S.C. 35, and the
Contract Work Hours and Safety Standards Act (commonly known as the
Construction Safety Act), 40 U.S.C. 333. The Walsh-Healey Act and
Construction Safety Act standards, in turn, had been adopted primarily
from recommendations of the American Conference of Governmental
Industrial Hygienists (ACGIH).
    For general industry (see 29 CFR 1910.1000, Table Z-3), the PEL for
crystalline silica in the form of respirable quartz is based on two
alternative formulas: (1) A particle-count formula, PELmppcf
= 250/(% quartz + 5); and (2) a mass formula proposed by ACGIH in 1968,
PEL = (10 mg/m\3\)/(% quartz + 2). The general industry PELs for
cristobalite and tridymite are one-half of the value calculated from
either of the above two formulas. For construction (29 CFR 1926.55,
Appendix A) and shipyards (29 CFR 1915.1000, Table Z), the formula for
the PEL for crystalline silica in the form of quartz
(PELmppcf = 250/(% quartz + 5)), which requires particle
counting, is derived from the 1970 ACGIH threshold limit value
(TLV).\2\ The formula based on particle-counting technology used in the
general industry, construction, and shipyard PELs is now considered
obsolete.
---------------------------------------------------------------------------

    \2\ The Mineral Dusts tables that contain the silica PELs for
construction and shipyards do not clearly express PELs for
cristobalite and tridymite. 29 CFR 1926.55; 29 CFR 1915.1000. This
lack of textual clarity likely results from a transcription error in
the Code of Federal Regulations. OSHA's current proposal provides
the same PEL for quartz, cristobalite, and tridymite, in general
industry, construction, and shipyards.
---------------------------------------------------------------------------

    In 1974, the National Institute for Occupational Safety and Health
(NIOSH) evaluated crystalline silica as a workplace hazard and issued
criteria for a recommended standard on occupational exposure to
crystalline silica (NIOSH, 1974). NIOSH recommended that occupational
exposure to crystalline silica be controlled so that no worker is
exposed to a time-weighted average (TWA) of free (respirable
crystalline) silica greater than 50 [mu]g/m\3\ as determined by a full-
shift sample for up to a 10-hour workday, 40-hour workweek. The
document also recommended a number of ancillary provisions for a
standard, such as exposure monitoring and medical surveillance.
    In December 1974, OSHA published an Advanced Notice of Proposed
Rulemaking (ANPRM) based on the recommendations in the NIOSH criteria
document (39 FR 44771, Dec. 27, 1974). In the ANPRM, OSHA solicited
``public participation on the issues of whether a new standard for
crystalline silica

should be issued on the basis of the [NIOSH] criteria or any other
information, and, if so, what should be the contents of a proposed
standard for crystalline silica.'' OSHA also set forth the particular
issues of concern on which comments were requested. The Agency did not
pursue a final rule for crystalline silica at that time.
    As information developed during the 1980s and 1990s, national and
international classification organizations came to recognize
crystalline silica as a human carcinogen. In June 1986, the
International Agency for Research on Cancer (IARC) evaluated the
available evidence regarding crystalline silica carcinogenicity and
concluded that it was ``probably carcinogenic to humans'' (IARC, 1987).
An IARC working group met again in October 1996 to evaluate the
complete body of research, including research that had been conducted
since the initial 1986 evaluation. IARC concluded that ``crystalline
silica inhaled in the form of quartz or cristobalite from occupational
sources is carcinogenic to humans'' (IARC, 1997).
    In 1991, in the Sixth Annual Report on Carcinogens, the U.S.
National Toxicology Program (NTP) concluded that respirable crystalline
silica was ``reasonably anticipated to be a human carcinogen'' (NTP,
1991). NTP reevaluated the available evidence and concluded, in the
Ninth Report on Carcinogens (NTP, 2000), that ``respirable crystalline
silica (RCS), primarily quartz dust occurring in industrial and
occupational settings, is known to be a human carcinogen, based on
sufficient evidence of carcinogenicity from studies in humans
indicating a causal relationship between exposure to RCS and increased
lung cancer rates in workers exposed to crystalline silica dust'' (NTP,
2000). ACGIH listed respirable crystalline silica (in the form of
quartz) as a suspected human carcinogen in 2000, while lowering the TLV
to 0.05 mg/m\3\ (ACGIH, 2001). ACGIH subsequently lowered the TLV for
crystalline silica to 0.025 mg/m\3\ in 2006, which is the current value
(ACGIH, 2010).
    In 1989, OSHA established 8-hour TWA PELs of 0.1 for quartz and
0.05 mg/m\3\ for cristobalite and tridymite, as part of the Air
Contaminants final rule for general industry (54 FR 2332, Jan. 19,
1989). OSHA stated that these limits presented no substantial change
from the Agency's former formula limits, but would simplify sampling
procedures. In providing comments on the proposed rule, NIOSH
recommended that crystalline silica be considered a potential
carcinogen.
    In 1992, OSHA, as part of the Air Contaminants proposed rule for
maritime, construction, and agriculture, proposed the same PELs as for
general industry, to make the PELs consistent across all the OSHA-
regulated sectors (57 FR 26002, June 12, 1992). However, on July 7 of
the same year, the U.S. Court of Appeals for the Eleventh Circuit
vacated the 1989 Air Contaminants final rule for general industry (Am.
Fed'n of Labor and Cong. of Indus. Orgs. v. OSHA, 965 F.2d 962 (1992)),
which also mooted the proposed rule for maritime, construction, and
agriculture. The Court's decision to vacate the rule forced the Agency
to return to the PELs adopted in the 1970s.
    In 1994, OSHA launched a process to determine which safety and
health hazards in the U.S. needed most attention. A priority planning
committee included safety and health experts from OSHA, NIOSH, and the
Mine Safety and Health Administration (MSHA). The committee reviewed
available information on occupational deaths, injuries, and illnesses
and held an extensive dialogue with representatives of labor, industry,
professional and academic organizations, the States, voluntary
standards organizations, and the public. The National Advisory
Committee on Occupational Safety and Health and the Advisory Committee
on Construction Safety and Health also made recommendations. Rulemaking
for crystalline silica exposure was one of the priorities designated by
this process. OSHA indicated that crystalline silica would be added to
the Agency's regulatory agenda as other standards were completed and
resources became available.
    In August 1996, the Agency initiated enforcement efforts under a
Special Emphasis Program (SEP) on crystalline silica. The SEP was
intended to reduce worker silica dust exposures that can cause
silicosis. It included extensive outreach as well as inspections. Among
the outreach materials available were slides presenting information on
hazard recognition and crystalline silica control technology, a video
on crystalline silica and silicosis, and informational cards for
workers explaining crystalline silica, health effects related to
exposure, and methods of control. The SEP provided guidance for
targeting inspections of worksites with employees at risk of developing
silicosis.
    As a follow-up to the SEP, OSHA undertook numerous non-regulatory
actions to address silica exposures. For example, in October of 1996,
OSHA launched a joint silicosis prevention effort with MSHA, NIOSH, and
the American Lung Association (DOL, 1996). This public education
campaign involved distribution of materials on how to prevent
silicosis, including a guide for working safely with silica and
stickers for hard hats to remind workers of crystalline silica hazards.
Spanish language versions of these materials were also made available.
OSHA and MSHA inspectors distributed materials at mines, construction
sites, and other affected workplaces. The joint silicosis prevention
effort included a National Conference to Eliminate Silicosis in
Washington, DC, in March of 1997, which brought together approximately
650 participants from labor, business, government, and the health and
safety professions to exchange ideas and share solutions to reach the
goal of eliminating silicosis. The conference highlighted the best
methods of eliminating silicosis and included problem-solving workshops
on how to prevent the disease in specific industries and job
operations; plenary sessions with senior government, labor, and
corporate officials; and opportunities to meet with safety and health
professionals who had implemented successful silicosis prevention
programs.
    In 2003, OSHA examined enforcement data for the years between 1997
and 2002 and identified high rates of noncompliance with the OSHA
respirable crystalline silica PEL, particularly in construction. This
period covers the first five years of the SEP. These enforcement data,
presented in Table 1, indicate that 24 percent of silica samples from
the construction industry and 13 percent from general industry were at
least three times the OSHA PEL. The data indicate that 66 percent of
the silica samples obtained during inspections in general industry were
in compliance with the PEL, while only 58 percent of the samples
collected in construction were in compliance.

     Table III-1--Results of Time-Weighted Average (TWA) Exposure Respirable Crystalline Silica Samples for
                                        Construction and General Industry
                                       [January 1, 1997-December 31, 2002]
----------------------------------------------------------------------------------------------------------------
                                                           Construction               Other than construction
                                                 ---------------------------------------------------------------
     Exposure (severity relative to the PEL)         Number of                       Number of
                                                      samples         Percent         samples         Percent
----------------------------------------------------------------------------------------------------------------
< 1 PEL.........................................             424              58            2226              66
1 x PEL to < 2 x PEL............................              86              12             469              14
2 x PEL to < 3 x PEL............................              48               6             215               6
>= 3 x PEL and higher (3+)......................             180              24             453              13
                                                 ---------------------------------------------------------------
    Total  of samples..................             738                            3363
----------------------------------------------------------------------------------------------------------------
Source: OSHA Integrated Management Information System.

    In an effort to expand the 1996 SEP, on January 24, 2008, OSHA
implemented a National Emphasis Program (NEP) to identify and reduce or
eliminate the health hazards associated with occupational exposure to
crystalline silica (OSHA, 2008). The NEP targeted worksites with
elevated exposures to crystalline silica and included new program
evaluation procedures designed to ensure that the goals of the NEP were
measured as accurately as possible, detailed procedures for conducting
inspections, updated information for selecting sites for inspection,
development of outreach programs by each Regional and Area Office
emphasizing the formation of voluntary partnerships to share
information, and guidance on calculating PELs in construction and
shipyards. In each OSHA Region, at least two percent of inspections
every year are silica-related inspections. Additionally, the silica-
related inspections are conducted at a range of facilities reasonably
representing the distribution of general industry and construction work
sites in that region.
    A recent analysis of OSHA enforcement data from January 2003 to
December 2009 (covering the period of continued implementation of the
SEP and the first two years of the NEP) shows that considerable
noncompliance with the PEL continues to occur. These enforcement data,
presented in Table 2, indicate that 14 percent of silica samples from
the construction industry and 19 percent for general industry were at
least three times the OSHA PEL during this period. The data indicate
that 70 percent of the silica samples obtained during inspections in
general industry were in compliance with the PEL, and 75 percent of the
samples collected in construction were in compliance.

     Table III-2--Results of Time-Weighted Average (TWA) Exposure Respirable Crystalline Silica Samples for
                                        Construction and General Industry
                                       [January 1, 2003-December 31, 2009]
----------------------------------------------------------------------------------------------------------------
                                                           Construction               Other than construction
                                                 ---------------------------------------------------------------
     Exposure (severity relative to the PEL)         Number of                       Number of
                                                      samples         Percent         samples         Percent
----------------------------------------------------------------------------------------------------------------
< 1 PEL.........................................             548              75             948              70
1 x PEL to < 2 x PEL............................              49               7             107               8
2 x PEL to < 3 x PEL............................              32               4              46               3
>= 3 x PEL and higher (3+)......................             103              14             254              19
                                                 ---------------------------------------------------------------
    Total  of samples..................             732                            1355
----------------------------------------------------------------------------------------------------------------
Source: OSHA Integrated Management Information System.

    Both industry and worker groups have recognized that a
comprehensive standard is needed to protect workers exposed to
respirable crystalline silica. For example, ASTM (originally known as
the American Society for Testing and Materials) has published