enforce (Document ID 4234, Part 2, p. 52). IUOE summarized one case
concerning an occupational fatality resulting from inadequate training
or knowledge and other cases supporting specific training for competent
persons (Document ID 4234, Part 2, pp. 55-56). ASSE cautioned that many
OSHA standards do not specify parameters for determining competency and
referred to the challenges in judging competency when litigating
citations (Document ID 4201, pp. 4-5).
    NIOSH requested that OSHA require competency training, as it did
for asbestos (29 CFR 1926.1101(o)(4)), and list requirements for
silica-specific training and capabilities for competent persons in the
standard or an appendix of the standard. NIOSH further stated that
``OSHA could consider allowing appropriate experience to qualify (e.g.,
learning by apprenticing to a trained silica-competent person).'' NIOSH
noted that such an approach is consistent with the ANSI A10.38 standard
that defines a competent person based on specific education, training,
or experience (Document ID 2177, Attachment B, p. 9).
    IUOE, ASSE, LHSFNA, and BCTD endorsed the competency objectives set
forth in an AIHA White Paper as a minimum body of knowledge for a
silica competent person (Document ID 4201, p. 6; 4207, p. 3; 4223, pp.
113-114). BCTD requested that the White Paper be included as a non-
mandatory appendix to the rule (Document ID 4223, pp. 113-114). The
AIHA White Paper indicates that a silica competent person can
demonstrate competency by completing a training course addressing the
criteria in the White Paper or successfully demonstrating the
capabilities described in the White Paper through training or direct
job experience. The competency objectives listed in the AIHA White
Paper include an understanding of (a) the role of a competent person;
(b) what silica is and where it is found; (c) silica hazards and
exposures, occupational exposure limits, and regulations; (d) how to
determine if silica is present through bulk sample analyses, safety
data sheets, or material checklists; (e) exposure ranges for common
construction tasks in the absence of controls and under conditions that
can result in higher exposures, and recognition of situations when a
qualified person needs to be called in; (f) effective use of controls
to reduce exposures and basic understanding of respiratory protection;
(g) understanding of need for oversight and quality assurance,
including review of exposure monitoring by a qualified person and
communication to other employers on a multi-employer sight; (h)
understanding of OSHA standard; and (i) understanding of authority,
responsibilities and procedures (e.g., resolving safety or health
situations) (Document ID 4076, pp. 4-9).
    Commenters further elaborated on training requirements and
competencies for a silica competent person. ASSE requested that OSHA
give clear guidance on what qualifies an individual to be designated a
competent person, asserted that certification in safety or industrial
hygiene should presume competency, recommended similar competency
requirements as the AIHA White Paper, and suggested that OSHA include
training competency requirements in a non-mandatory appendix. ASSE also
noted that the asbestos standard, 29 CFR 1926.1101(o)(4), requires
competent persons to complete an Environmental Protection Agency
course, and although an equivalent course does not exist for
crystalline silica, training to address competencies for a silica
competent person could be added to a 30-hour course for construction
(Document ID 4201, pp. 2-6).
    As discussed in detail in the summary and explanation of
Communication of Respirable Crystalline Silica Hazards to Employees,
BCTD requested a tiered approach to training in which the competent
person would receive training necessary to perform his or her duties,
in addition to awareness training for all covered employees and hands-
on training on engineering controls and work practices for employees
performing tasks that generate silica dust (Document ID 4223, pp. 117-
118). IUOE, LHSFNA, and BAC similarly advocated competent person
training as part of a tiered approach and stressed that the competent
person receive site-specific training on engineering controls (Document
ID 2262, pp. 39-40; 4207, p. 5; 4219, p. 24). Tom Nunziata, Training
Coordinator for LHSFNA, stressed that the minimum training for a
competent person should be at least the training required for employees
performing tasks that generate silica dust (Document ID 3589, Tr.
4221). Similar to NIOSH, Travis Parsons testified that experience can
contribute to a competent person's knowledge (Document ID 3589, Tr.
4197-4198).
    LHSFNA indicated that competent person training should be tailored
based on needs and exposure potential (Document ID 4207, p. 5). Other
commenters provided numerous examples of unique training requirements
for heavy equipment operators. For example, Gary Fore, retired Vice
President for Health, Safety, and Environment for NAPA, referenced best
practices for inspection of controls on asphalt milling machines by
competent persons and testified that those machines are very
complicated and sophisticated (Document ID 3583, Tr. 2182-2183).
Therefore, training is required to detect issues requiring maintenance,
such as a plugged or inappropriately placed nozzle (Document ID 2181,
p. 10). IUOE commented that a competent person must have the knowledge
to make informed judgments about the potential for silica exposures to
exceed the action level (Document ID 2262, pp. 42-43). Martin Turek,
Assistant Coordinator and Safety Administrator for IUOE Local 150, and
Kyle Zimmer gave several examples of variables that could affect silica
exposures in earth moving tasks, such as weather (e.g., wind, humidity)
and soil compositions and handling (e.g., clay versus rock, distance
soil is dropped from a bucket) (Document ID 3583, Tr. 2351-2352, 2356-
2359). Matt Gillen, Deputy Director of NIOSH's Office of Construction
Safety and Health, testified that a competent person should be able to
recognize variability issues and make changes to address them (Document
ID 3579, Tr. 205-206).
    NRECA commented that a competent person for rural electric
utilities should be trained in setting up air monitoring, setting
boundaries for control zones, physical characteristics of crystalline
silica, and PPE such as respirators (Document ID 2365, pp. 19-20).
Francisco Trujillo testified that a competent person should have
knowledge of work processes and their associated hazards and possibly,
some knowledge of previous sampling evaluations to know if employees
might be overexposed (Document ID 3585, Tr. 2980-2981). Upstate Medical
University recommended that the competent person be trained on the
respirable crystalline silica standard, the hierarchy of controls,
exposure determinants, and the written control plan (Document ID 2244,
p. 4).
    Ameren Corporation opposed specific training requirements for a
competent person (Document ID 2315, p. 2). CISC stated that if OSHA
does include a competent person requirement in the

standard, the agency should not require training because:

    An individual's experience, job training, and silica awareness
training, in the CISC's view, will provide the capabilities
envisioned by OSHA for a competent person with respect to
crystalline silica. For silica in construction, the CISC
respectfully believes that no specific training for a ``competent
person'' is required. Furthermore, the Agency has traditionally not
included specific competent person training requirements in its
construction standards, instead taking a performance-oriented
approach to the requirements and definition. There is nothing unique
about silica that would cause the Agency to deviate from this past
approach (Document ID 2319, pp. 127-128).

    OSHA concludes, after consideration of all the comments, that it is
not practical to specify in the rule the elements and level of training
required for a competent person. The Agency does not find it
appropriate to mandate a ``one size fits all'' set of training
requirements to establish the competency of competent persons in every
conceivable construction setting. Therefore, the training requirement
for a competent person is performance-oriented. This approach is
consistent with most OSHA construction standards, such as cadmium (29
CFR 1926.1127) and lead (29 CFR 1926.62), which include a performance-
based approach by not specifying training or qualifications required
for a competent person.
    It is evident from the comments that controlling respirable
crystalline silica exposures involves tailoring controls and work
practices to each particular work setting. Moreover, training is
addressed by the HCS and paragraph (i) of the standard for
construction. The HCS and paragraph (i) require that employees be
trained on subjects that overlap with competencies listed in the AIHA
White Paper. For example paragraph (h)(3)(i) of the HCS (29 CFR
1910.1200) requires training of covered employees on methods to detect
the release of hazardous chemicals (in this case, respirable
crystalline silica). The respirable crystalline silica standard for
construction requires training on health hazards, tasks that could
result in exposures, engineering and work practice controls and
respiratory protection, and the contents of the standard (paragraphs
(i)(2)(i)(A-D)).
    OSHA concludes that successful completion of training requirements
in the HCS and the standard for construction impart a high level of
competency to employees. The training focuses on general requirements
that apply to most construction settings and should be sufficient to
provide an employee with the knowledge and ability to be designated a
competent person at some companies. Competent persons might require
more knowledge and training in certain circumstances, but that would
vary widely among construction companies. For example, competent
persons at a small residential construction company might only need
training on controls for power tools that they do not typically use to
perform their own tasks, so that they could assist employees with
questions about or problems with dust controls on those tools. In
contrast, a competent person for heavy equipment tasks may require more
specialized training in heavy equipment inspection or identifying
various soil types to estimate exposure potential. Because companies
covered under the construction standard conduct a wide range of tasks
involving unique scenarios, training requirements will vary widely
among different companies. It is, therefore, the employer's
responsibility to identify and provide any additional training that the
competent person needs to implement the employer's written exposure
control plan.
    Finally, a compliance officer could ascertain whether the employer
is in compliance with the competent person requirement by asking
questions to assess whether the competent person has adequate knowledge
to perform his or her duties, such as an understanding of engineering
controls and how to recognize if they are not functioning properly. As
is the case with training of all employees, the employer is responsible
for determining that a competent person is adequately trained and
knowledgeable to perform his or her duties.
    Competent Person (General Industry). As part of the proposed
written access control plan, OSHA proposed that a competent person
identify and maintain regulated areas in workplaces covered by the
general industry and maritime standard. AFL-CIO and USW requested
expanded competent person duties and training requirements for general
industry and maritime because a competent person could recognize and
take action to protect employees from high exposures (Document ID 4204,
pp. 58-60; 4214, pp. 14-16). AFL-CIO urged OSHA to reinstate the
competent person duties from the 2003 SBREFA draft standard (Document
ID 4204, pp. 58-60). USW commented that a competent person could ensure
that hazards are recognized, employees receive proper training,
adequate controls and PPE are implemented, and an effective exposure
control plan is developed (Document ID 4214, pp. 14-15). In describing
how a competent person is relevant to general industry, AFL-CIO pointed
to testimony by employees who were trained to evaluate the function of
ventilation systems (Document ID 4204, p. 60). AFL-CIO also asserted
that NIOSH and AIHA urged OSHA to include a competent person
requirement for both general industry and construction (Document ID
4204, pp. 59-60). OSHA examined the AIHA and NIOSH comments referenced
by AFL-CIO and identified only recommendations for a competent person
regarding construction-related topics, such as Table 1 (Document ID
2169, pp. 4-5; 2177, Attachment B, pp. 8-10, 25-26).
    OSHA is not requiring a competent person for the general industry
and maritime standard. OSHA has determined that in most cases, general
industry scenarios are not as variable as those in construction. For
example, most work is performed indoors and therefore, not subject to
variables such as wind shifts and moving exposure sources that could
significantly affect exposures or complicate establishment of regulated
areas. In general industry and maritime, controls are not usually built
into tools that require action by the individual employees who use them
to function effectively. The exposure assessments that employers in
general industry and maritime are required to conduct will verify that
controls are functioning effectively. Employers covered under the
general industry and maritime standard are more likely to have health
and safety professionals on staff who could assist with implementation
of the standard. Finally, competent persons have not been included in
other OSHA substance-specific standards for general industry. For
example, a competent person requirement was included in the
construction standard for cadmium because of environmental variability
and the presence of multiple employers on the job site, but a competent
person requirement was not included in the general industry standard
for cadmium (29 CFR 1910.1027; 29 CFR 1926.1127; 57 FR 42101, 42382 (9/
14/1992)). Moreover, as explained in the summary and explanation of
Regulated Areas, establishing regulated areas is reasonable in most
general industry scenarios because employers are required to conduct
exposure assessment and are thus able to determine the boundaries of a
regulated area. Therefore, the general industry and maritime standard
requires regulated areas that are demarcated and posted with warning
signs. This negates the

need for a competent person to identify and maintain regulated areas.
These factors explain and support OSHA's conclusion that there is no
regulatory need for including a competent person requirement in the
respirable crystalline silica standard for general industry and
maritime.
    Comparison to ASTM Standards. The written exposure control plan is
comparable to the ASTM standards in some respects and different in
others. Section 4.2.6 of ASTM Standard E 1132-06 and Section 4.2.5 of
ASTM standard E 2625-09 recommend written exposure control plans for
areas with persistent overexposures; address engineering, work
practice, and administrative controls; and call for a root cause
analysis to investigate the causes of the overexposure, identify
remedies, and conduct follow-up sampling to verify that exposures are
below the PEL (Document ID 1466, p. 2; 1504, p. 2). The major
difference between the written plans in the ASTM standards and the
written plans in the respirable crystalline silica rule is that the
written plans for the respirable crystalline silica rule are not
limited to overexposure scenarios. The ASTM standards address work
practices and administrative controls, but the written exposure control
plans in the respirable crystalline silica rule further explain what
those practices and controls are (i.e., restricting access as needed
(construction standard only), engineering controls, work practices,
respiratory protection, and housekeeping methods). In addition, the
written exposure control plans in the respirable crystalline silica
rule are implemented by a competent person (construction standard
only), are required to be reviewed and updated at least annually by the
employer, and are to be made available to employees, employee
representatives, OSHA, and NIOSH upon request.
    The requirements of the rule for respirable crystalline silica
better protect employees and, therefore, better effectuate the purposes
of the OSH Act of 1970 than the ASTM standards. Because the written
plans are required for all workplaces covered by the rule, they help to
maintain comprehensive and consistent controls, which can prevent
overexposures from occurring. The provision for annual review ensures
that the plans remain effective, and the provision for making the plans
available to employees helps to make employees aware of the protections
they should expect. More details about how the requirements of the rule
better effectuate the requirements of the OSH Act are discussed above.

Medical Surveillance

    Paragraph (i) of the standard for general industry and maritime
(paragraph (h) of the standard for construction) sets forth
requirements for the medical surveillance provisions. The paragraph
specifies which employees must be offered medical surveillance, as well
as the frequency and content of medical examinations. It also sets
forth the information that the physician or other licensed health care
professional (PLHCP) is to provide to the employee and employer.
    The purpose of medical surveillance for respirable crystalline
silica is, where reasonably possible, (1) to identify respirable
crystalline silica-related adverse health effects so that appropriate
intervention measures can be taken; (2) to determine if an employee can
be exposed to respirable crystalline silica in his or her workplace
without increased risk of experiencing adverse health effects, or in
other words, to determine if an employee has any condition, regardless
of the cause, that might make him or her more sensitive to respirable
crystalline silica exposure; and (3) to determine the employee's
fitness to use respirators. The inclusion of medical surveillance in
this rule is consistent with Section 6(b)(7) of the Occupational Safety
and Health (OSH) Act (29 U.S.C. 655(b)(7)) which requires that, where
appropriate, medical surveillance programs be included in OSHA
standards to determine whether the health of employees is adversely
affected by exposure to the hazard addressed by the standard. Almost
all other OSHA health standards have also included medical surveillance
requirements and OSHA finds that a medical surveillance requirement is
appropriate for the respirable crystalline silica rule because of the
health risks resulting from exposure.
    General. Paragraph (i)(1)(i) of the standard for general industry
and maritime requires employers to make medical surveillance available
for employees who will be occupationally exposed to respirable
crystalline silica at or above the 25 [mu]g/m\3\ action level for 30 or
more days per year. Paragraph (h)(1)(i) of the standard for
construction requires employers to make medical surveillance available
to employees who will be required under this section to use a
respirator for 30 or more days per year. Thus, employers are required
to determine if their employees will be exposed at or above the action
level of 25 [mu]g/m\3\ in general industry and maritime, or required to
wear a respirator under the construction standard for 30 or more days
per year (i.e., the next 365 days), and then make a medical examination
available to those employees who meet these criteria under two
scenarios: (1) Within 30 days of initial assignment, unless the
employee has had a current examination that meets the requirements of
this rule within the last three years (paragraph (i)(2) of the standard
for general industry and maritime, paragraph (h)(2) of the standard for
construction) and (2) within three years from the last initial or
periodic examination (paragraph (i)(3) of the standard for general
industry and maritime, paragraph (h)(3) of the standard for
construction). As in previous OSHA standards, both standards are
intended to encourage participation by requiring that medical
surveillance be offered at no cost to the employee and at a reasonable
time and place. Under the ``at no cost to the employee'' proviso, if
participation requires travel away from the worksite, the employer will
be required to bear the cost of travel, and employees will have to be
paid for time spent taking medical examinations, including travel time.
    Some employers and industry representatives questioned the general
need for medical surveillance or expressed their concerns with the
medical surveillance requirement. For example, OSCO Industries, Inc.
argued that medical surveillance would not identify many employees with
silicosis and OSCO Industries and National Association of Home Builders
(NAHB) emphasized the progress that has already been made in
eliminating silicosis (Document ID 1992, p. 11; 2296, p. 43). Fann
Contracting, Inc. stated that medical surveillance is not needed
because employees exposed above the permissible exposure limit (PEL)
are required to wear respirators and they should therefore be protected
(Document ID 2116, Attachment 1, p. 43).
    OSHA does not find these comments persuasive. As discussed in
Section VI, Final Quantitative Risk Assessment and Significance of
Risk, OSHA has found that employees exposed to respirable crystalline
silica at the preceding PELs are at significant risk of material
impairment of health. Although the revised PEL of 50 [mu]g/m\3\
substantially decreases risks, the risk remains significant at and
below the PEL, including at the action level of 25 [mu]g/m\3\.
Consequently, even employees exposed at the action level are at
significant risk of developing silicosis and other respirable
crystalline silica-related diseases. Based on these risk assessment
findings, OSHA concludes that silicosis and other respirable

crystalline silica-related illnesses are an ongoing occupational risk.
OSHA expects that those illnesses are likely to be detected as part of
medical surveillance, and the detection of these illnesses will benefit
employees.
    Even employees required to wear respiratory protection in high
exposure environments are at risk of developing disease. As OSHA notes
in the summary and explanation of Methods of Compliance, respirators
fully protect employees only if they are properly fitted and maintained
correctly and replaced as necessary; they do not protect employees if
they are not used consistently and properly. The committee that
developed the ASTM International (ASTM) standard, ASTM E 2625-09,
Standard Practice for Controlling Occupational Exposure to Respirable
Crystalline Silica for Construction and Demolition Activities, also
concluded that medical surveillance is needed for employees who wear
respirators to ensure that the respiratory protection is working
(Document ID 3580, Tr. 1452). (This requirement is consistent with that
in ASTM E 1132-06, Standard Practice for Health Requirements Relating
to Occupational Exposure to Respirable Crystalline Silica.)
Consequently, OSHA concludes that the requirement for respiratory
protection for exposures exceeding the PEL does not obviate the need
for medical surveillance.
    Employers also expressed concern about responsibility for exposures
occurring through other employment or non-occupational sources (e.g.,
environmental exposures) (e.g., Document ID 2116, Attachment 1, pp. 20,
36, 37, 39; 2295, p. 2; 2296, p. 31; 3531, p. 9). Construction Industry
Safety Coalition (CISC) and Holes Incorporated questioned how medical
surveillance would decrease exposures, and Holes Incorporated stated it
would not prevent the onset of silicosis (Document ID 2319, p. 116;
2338, p. 6).
    OSHA stresses that the main purposes of medical surveillance are
early detection of disease related to respirable crystalline silica
exposure so appropriate intervention methods can be taken, to let
employees know if they have a condition that might make them more
sensitive to respirable crystalline silica exposure, and to assess
fitness to wear a respirator. The purpose of medical surveillance is
not to identify which employer is responsible for illnesses resulting
from respirable crystalline silica exposures or must offer financial
compensation. OSHA agrees with the Building Construction and Trades
Department, AFL-CIO (BCTD), which stated that ``[e]arly detection of
silica-related medical conditions will enable employees to make
informed decisions about their work, their medical care and their
lifestyles'' (Document ID 4223, p. 123). For example, as the American
College of Occupational and Environmental Medicine (ACOEM) and the
National Institute for Occupational Safety and Health (NIOSH) stated,
an early diagnosis allows an employee to consider employment choices
that minimize or eliminate respirable crystalline silica exposure to
decrease the risk of progression or exacerbation of disease (Document
ID 1505, p. 3; 3579, Tr. 257). In another example, an early diagnosis
of silicosis allowed bricklayer Dennis Cahill, representing the
International Union of Bricklayers and Allied Craftworkers (BAC), to
manage his health by getting flu and pneumonia shots, avoiding the
public during cold season, and staying indoors during periods of high
air pollution (Document ID 3585, Tr. 3089, 3104). OSHA finds that
although medical surveillance does not reduce exposures, like
engineering controls do, it is nonetheless an integral component of
this (and most) occupational safety and health standards and important
in its own right for safeguarding the health of employees exposed to
respirable crystalline silica.
    OSHA also agrees with the viewpoint expressed so well by Mr.
Cahill, that employees who are knowledgeable about their health risks
will take actions in response to information from medical surveillance.
Such actions will likely benefit not only the employees but also
employers because their employees are likely to be healthier. Members
of the medical community, labor unions, employee health advocate
groups, and industry groups emphasized the value of early detection for
intervention purposes (e.g., Document ID 2080, p. 9; 2178, Attachment
1, p. 2; 2351, p. 15; 3541, p. 1; 3577, Tr. 570-571; 3588, Tr. 3751;
3589, Tr. 4292; 4204, p. 79; 4219, p. 28; 4223, pp. 123-124). In
addition, more than 100 commenters including construction employees,
employee health advocates, medical professionals, and employers or
industry representatives voiced their general support for medical
examinations in the respirable crystalline silica rule (e.g., Document
ID 1771, p. 1; 2030; 2268; 2134, p. 10; 2403; 3294).
    Some commenters representing the construction industry questioned
the practicality of medical surveillance for construction employees due
to a number of particular difficulties, such as the short-term nature
and high turnover rate of construction jobs (e.g., Document ID 2116,
Attachment 1, p. 20; 2187, p. 7; 2247, p. 1; 2276, p. 10; 2289, p. 8;
2295, p. 2; 2296, pp. 42-43; 3230, p. 1; 3442, pp. 5-6; 4029, p. 3;
4217, p. 21). For example, American Subcontractors Association and Hunt
Construction Group stated that the difficulty in tracking medical
surveillance in a mobile work force could result in repeated,
unnecessary testing for construction employees (Document ID 2187, p. 7;
3442; pp. 5-6). Kenny Jordan, Executive Director of the Association for
Energy Services Companies (AESC), which represents another industry
with high turnover rates, expressed similar concerns about repeated
testing, although he did not oppose medical surveillance and asked for
a medical record that would follow the employee (Document ID 3589, Tr.
4063). The Laborers' Health and Safety Fund of North America (LHSFNA)
supported medical surveillance, but expressed concerns about repeated
testing and urged OSHA to include provisions for contractor
associations and union management funds to coordinate medical
examinations for employees who work for several contractors in a year
to avoid unnecessary medical examinations (Document ID 4207, p. 5).
    After considering these comments, OSHA concludes that the necessity
for medical surveillance is not negated by the practical challenges of
tracking medical surveillance in a mobile work force. OSHA has included
medical surveillance in other health standards where construction has
been a primary industry impacted by those rules (e.g., lead, asbestos,
and chromium (VI)) and finds no reason why the respirable crystalline
silica standard for construction should be an exception. Moreover,
there are practical solutions for tracking medical surveillance to
avoid duplicative, unneeded testing. One simple solution, which OSHA
has included in this rule, is to have employers ensure that each
employee receives a dated copy of the PLHCP's written medical opinion
for the employer. The employee can then provide the opinion to his or
her next employer as proof of up-to-date medical surveillance (Document
ID 4207, p. 5; 4223, p. 125). Employers could also work with a third
party, such as an industry association, union, or local medical
facility, to coordinate, provide, or keep records of medical
examinations (Document ID 4207, p. 5; 4236, pp. 3-4, Appendix 1, pp. 1-
2). Such an approach has been used by LHSFNA to avoid unnecessary
testing of employees who work for several contractors in a

year (Document ID 3759, Appendix 3). The respirable crystalline silica
rule does not preclude such pooled employer-funded approaches, and OSHA
expects such coordination to occur in response to this rule. OSHA
concludes that there are practical solutions for addressing the
challenge posed by employee mobility and turnover in the construction
industry, and those factors should not prevent construction employees
who are eligible for medical surveillance under the standard (i.e.,
those who will be engaged in tasks requiring respirator use for 30 or
more days in the upcoming year) from being offered such surveillance as
part of the employer's compliance obligations.
    In the proposed standards, OSHA specified that employers must
``make medical surveillance available'' to those employees who would be
occupationally exposed to respirable crystalline silica above the PEL
for 30 or more days a year. The Agency received a variety of comments
on this provision. First, NAHB expressed concern about employees
refusing to participate in medical surveillance (Document ID 2296, p.
32). OSHA emphasizes that the mandate to offer medical surveillance to
eligible employees does not include a requirement for employee
participation, and no liability for non-participation arises so long as
the employer does not discourage such participation.
    Second, OSHA received numerous comments related to the proposed
triggers for determining which employees should be provided medical
surveillance. Some commenters focused on the level of exposure at which
medical surveillance should be triggered. For example, Ameren
Corporation agreed with the proposed PEL trigger, noting that it is
consistent with the asbestos standard (Document ID 2315, p. 9). Some
stakeholders from industry, the medical community, and employee health
advocate groups also supported a trigger based on a PEL (e.g., Document
ID 1785, pp. 4-5; 2175, p. 5; 2291, p. 26; 2327, Attachment 1, p. 26;
2339, p. 5; 2379, Appendix 1, p. 71; 3577, Tr. 784-785).
    Other commenters advocated that medical surveillance should be
triggered on an action level. However, these stakeholders disagreed on
what the action level should be. For example, some commenters, like the
National Industrial Sand Association (NISA), American Petroleum
Institute, and other employers and industry groups, advocated an action
level trigger of 50 [mu]g/m\3\ (with a higher PEL of 100 [mu]g/m\3\)
(e.g., Document ID 1963, pp. 1-2; 2196, Attachment 1, pp. 1-2; 2200,
pp. 1-2; 2213, p. 3; 2232, p. 1; 2233, p. 1; 2301, Attachment 1, p. 78;
2311, p. 3; 4208, pp. 7-9). NISA did not agree with OSHA that
significant risk remains at 50 [mu]g/m\3\, but stated that an action
level trigger is consistent with other OSHA standards; can lead to
identification of individuals who might be more susceptible to silica
exposures because of factors, such as genetic variability, prior work
exposures, or smoking; addresses variability in workplace exposures;
and provides an economic incentive for employers to maintain lower
exposures (Document ID 2195, pp. 6, 30, 32).
    Other stakeholders, including representatives of labor unions, the
medical community, and other employee health advocate groups, stated
that the proposed action level of 25 [mu]g/m\3\, or even a lower level,
should trigger medical surveillance in general industry (e.g., Document
ID 2157, p. 7; 2178, Attachment 1, p. 2; 2240, p. 3; 2282, Attachment
3, p. 14; 2336, p. 11; 2256, Attachment 2, p. 9; 2351, pp. 13-15; 3516,
p. 3; 3541, p. 4). Other members of the medical community and employee
health advocate groups also voiced general support for an action level
trigger of 25 [mu]g/m\3\ or lower (e.g., Document ID 2080, p. 5; 2176,
p. 2; 3538, Attachment 1, pp. 3-4).
    American Federation of Labor and Congress of Industrial
Organizations (AFL-CIO) supported an action level trigger of 25 [mu]g/
m\3\ because the union agreed with OSHA about the remaining significant
risk for diseases at a PEL of 50 [mu]g/m\3\ and because an action level
at half the PEL would be consistent with the majority of OSHA health
standards (Document ID 4204, pp. 51, 79-80). Other representatives from
the medical community, labor unions, and other employee health advocate
groups, who also supported an action level trigger of 25 [mu]g/m\3\ or
lower, expressed similar thoughts about significant risk or consistency
with past standards (Document ID 2080, p. 5; 2157, p. 7; 2176, p. 2;
2178, Attachment 1, p. 2; 2282, Attachment 3, p. 22; 2336, p. 11; 3516,
p. 3; 3535, p. 2; 3541, pp. 14-15). Some of those same commenters,
including the United Automobile, Aerospace and Agricultural Implement
Workers of America (UAW) and ACOEM, supported an action level trigger
because of the variability of workplace exposures (Document ID 2282,
Attachment 3, p. 14; 3577, Tr. 766-767); the medical society Collegium
Ramazzini and United Steelworkers (USW) also noted an economic benefit
for employers to maintain lower exposures (Document ID 2336, p. 11;
3541, p. 15). Lastly, AFL-CIO noted that because OSHA proposed a
requirement for exposure assessment in general industry, employers will
know if employees are exposed above the action level; the same is not
true in construction because employers may use Table 1 instead of
conducting exposure assessments (Document ID 4204, pp. 80-81).
    OSHA also received comments on whether medical surveillance should
be triggered by a number of days of exposure at a certain level. For
example, NISA objected to the proposed 30-day exposure-duration trigger
for medical surveillance and stated that it should be offered to all
employees with likely exposure to respirable crystalline silica above
the action level (Document ID 4208, p. 8, Fn 12). The Asphalt Roofing
Manufacturers Association (ARMA) supported the 30-day exposure-duration
trigger for medical surveillance because some employees are only
infrequently exposed above the PEL as a result of scheduled maintenance
tasks performed once or twice per year or when filling in for other
employees, and the 30-day trigger would exclude employees with lower
average exposures (Document ID 2291, p. 26). Other commenters
representing industry or the medical community also agreed with the 30-
day exposure-duration trigger (e.g., Document ID 2080, p. 5; 2157, p.
7; 2175, p. 5; 2178, Attachment 1, p. 2; 2301, Attachment 1, p. 78;
2311, p. 3; 2315, p. 9; 2327, Attachment 1, p. 26; 2379, Appendix 1, p.
71; 3541, p. 14).
    OSHA agrees with the majority of commenters who indicated that
maintaining the 30-day exposure-duration trigger is appropriate for
general industry and maritime because the health effects of respirable
crystalline silica occur as a result of repeated exposures and
concludes that a 30-day trigger is a reasonable benchmark for capturing
cumulative effects caused by repeated exposures. Including a 30-day
exposure-duration trigger also maintains consistency with other OSHA
standards, such as chromium (VI) (29 CFR 1910.1026), cadmium (29 CFR
1910.1027), lead (29 CFR 1910.1025), and asbestos (29 CFR 1910.1001).
OSHA also agrees with commenters who indicated that triggering medical
surveillance at the action level of 25 [mu]g/m\3\ addresses residual
significant risk and varying susceptibility of employees that can
result in some experiencing adverse health effects at lower exposure
levels. An action level trigger in the standard for general industry
and maritime is also appropriate based on variability in exposure
levels and the availability of exposure assessment data in general

industry and maritime. However, OSHA has concluded that a delayed
implementation of the action level trigger for medical surveillance is
appropriate. Therefore, as indicated in the Summary and Explanation for
Dates, medical surveillance will be triggered by exposures exceeding
the PEL for 30 or more days per year during the first two years after
medical surveillance requirements commence (i.e., beginning two years
after the effective date). After that time (i.e., four years after the
effective date), medical surveillance will be triggered by exposures
exceeding the action level for 30 or more days per year (paragraph
(l)(4)). This approach will focus initial medical surveillance efforts
on those employees at greatest risk, while giving most employers
additional time to fully evaluate the engineering controls they have
implemented in order to determine which employees meet the action level
trigger for medical surveillance.
    OSHA intends to conduct a retrospective review five years after the
action level trigger is fully implemented (i.e., at nine years after
the effective date of the standard for general industry and maritime)
to gain a better understanding of the effectiveness of the action level
trigger for medical surveillance. OSHA will engage other federal
agencies, such as NIOSH, and stakeholders as appropriate, and will
issue a report about the findings of the evaluation.
    Construction industry representatives, employee health advocates,
and others also commented on OSHA's proposed use of the PEL to trigger
medical surveillance in the standard for construction. The Center for
Progressive Reform (CPR) and Charles Gordon, a retired occupational
safety and health attorney, advocated an action level trigger for
medical surveillance; Mr. Gordon also requested that conducting Table 1
activities trigger medical surveillance (Document ID 2351, p. 13; 4236,
pp. 3-4). Fann Contracting supported a PEL trigger for medical
surveillance (Document ID 2116, Attachment 1, p. 42). BAC and BCTD
supported the PEL (as determined by monitoring) or Table 1 tasks
requiring respirator use as triggers for medical surveillance in
construction because employees using Table 1 would not be required to
conduct exposure assessments and therefore would not know if exposures
exceed the action level (Document ID 4219, p. 29; 4223, p. 124). [Note
1 for proposed Table 1 indicated that required respirator use in Table
1 presumed exposures exceeding the PEL (78 FR 56273, 56499 (9/12/13))].
In prehearing comments, LHSFNA supported a PEL trigger as a practical
approach and requested that medical surveillance be triggered by tasks
(Document ID 2253, p. 5). In its post-hearing comments, however, LHSFNA
recommended that medical surveillance be required for employees who are
required to wear a respirator since those employees would already need
to undergo a medical evaluation to make sure they can safely wear a
respirator (as required by the respiratory protection standard)
(Document ID 4207, pp. 4-5).
    After reviewing these comments, OSHA concludes that an action level
trigger is not practical in the construction industry because many
employers will be using Table 1, and, therefore, will not have an
exposure assessment indicating if the action level is met or exceeded.
OSHA acknowledges that some construction employees who are not required
to use respirators for 30 or more days per year are at significant
risk, but has decided that triggering medical surveillance based on
respirator use is the most practical trigger for the construction
standard. Triggering medical surveillance in this manner is consistent
with the proposed rule, because respirator use under Table 1 is based
on tasks in which exposures consistently (more often than not) exceed
the revised PEL, as found in OSHA's technological feasibility analyses
of the various tasks included in Table 1 (see Chapter IV of the Final
Economic Analysis and Final Regulatory Flexibility Analysis (FEA) and
the summary and explanation for Specified Exposure Control Methods).
OSHA expects most construction employers to be following Table 1, and
therefore decided it also made the most practical sense to tie medical
surveillance to required respirator use. In addition, use of the
respirator trigger allows construction employers to more efficiently
determine if the 30-day duration trigger is met in cases where one of
their employees may be required to use respirators when doing Table 1
tasks and while doing tasks (e.g., abrasive blasting) that are not on
Table 1 but are determined to have exposures above the PEL based on
exposures assessments conducted under paragraph (d)(2) of the standard
for construction. Finally, OSHA decided not to expand the trigger for
medical surveillance to Table 1 tasks that do not require respirator
use because many employees engaged in those tasks will be exposed below
the action level (see Chapter III of the FEA).
    Some commenters expressed concerns about the practicality of
requiring employers to offer medical surveillance for exposures
exceeding a trigger level for 30 days or more in the construction
industry. George Kennedy, Vice President of Safety for the National
Utility Contractors Association, testified that they do not know what
employees are doing in the field each day and so will have to assume
that they are exposed and, therefore, offer medical surveillance to
every employee (Document ID 3583, Tr. 2245). BCTD questioned the
feasibility of the 30-day exposure-duration trigger because the
transient nature of construction work makes it difficult to predict if
an employee will be exposed for 30 days; the American Industrial
Hygiene Association (AIHA), AFL-CIO, and LHSFNA expressed similar views
(Document ID 2169, p. 6; 4204, p. 81; 4207, p. 4; 4223, p. 125). CISC
and some of its member companies questioned how an employer would know
if employees were exposed above the PEL for 30 or more days a year
unless they were following Table 1 or conducting near continuous
monitoring (Document ID 2269, pp. 6-7; 2289, p. 8; 2319, p. 116). CISC
and AIHA questioned how OSHA could verify the number of days an
employee was exposed (Document ID 2169, p. 6; 2319, p. 116). Larger
employers, such as Fann Contracting, expressed the challenges of
tracking employee exposures due to large numbers of employees and
various ongoing projects (e.g., Document ID 2116, Attachment 1, p. 11).
    OSHA acknowledges that tracking exposures in construction can be
challenging but observes that some employers are currently able to
track employee exposures to determine which employees should be offered
medical surveillance. For example, Kevin Turner, Director of Safety at
Hunt Construction Group and representing CISC, testified that safety
representatives on job sites keep track of exposures based on
employees' schedules, and the company provides medical surveillance for
employees exposed above the preceding construction PEL for 30 or more
days a year (Document ID 3580, Tr. 1535-1536). Francisco Trujillo,
Safety Director at Miller and Long, Inc., testified that at his
company, they conduct hazard assessments based mainly on the tasks the
employees will be performing, to determine which employees are likely
to be exposed above the preceding PEL, and they offer those employees
medical evaluations as part of the company's respiratory protection
program. The company has a system that monitors participating
employees' training, medical evaluations, and fit tests. The system
sends email reminders to company

representatives when the participating employees are due to be re-
examined or re-evaluated. However, Mr. Trujillo expressed concern that
if the number of employees participating in the program greatly
increases, then maintaining the company's tracking program would become
a more daunting task (Document ID 3585, Tr. 3008-3010).
    After reviewing the comments and testimony submitted on the
proposed construction trigger, OSHA concludes that the special
circumstances in construction, such as lack of exposure data for
employees using Table 1 or difficulties in tracking exposures for
numerous short-term assignments conducted at various sites, warrant a
simpler approach for triggering medical surveillance. Therefore, OSHA
revised paragraph (h)(1)(i) of the standard for construction to require
that employers offer medical surveillance to employees who will be
required to wear a respirator under this standard for 30 or more days a
year to limit exposure to respirable crystalline silica. Under the
standard for construction, employees must wear a respirator when
required to do so under Table 1 (paragraph (c)) or when, pursuant to
the performance option or the scheduled monitoring option set forth in
paragraph (d)(2), their exposures exceed the PEL (paragraph
(e)(1)(ii)). Respirator use under Table 1 is equivalent to the PEL
because the tasks that require respirator use are those that, in its
technological feasibility analysis of the construction industry, OSHA
has determined result in exposures exceeding 50 [mu]g/m\3\ a majority
of the time (see Chapter IV of the FEA and the summary and explanation
of Specified Exposure Control Methods). Based on the number of
commenters who indicated that exposure assessment is not practical in
construction because of changing tasks and conditions (see summary and
explanation of Exposure Assessment), OSHA expects most employers to use
Table 1 for tasks listed on the Table (i.e., most of the tasks that
generate silica exposure in construction). Under any available exposure
control method, however, the most convenient way for construction
employers to determine eligibility for medical surveillance is by
counting the number of days the employee will be required to wear a
respirator. Because respirator use is tied with certain tasks in Table
1, medical surveillance based on respirator use in Table 1 is
consistent with the task-based approach described by Francisco Trujillo
above. It is also consistent with the task-based triggers in the
cadmium construction standard (29 CFR 1926.1127) and operation-based
triggers (e.g., Class I work) in the asbestos construction standard (29
CFR 1926.1101).
    OSHA concludes that a trigger based on respirator use will greatly
simplify determining which employees covered by the construction
standard must be offered medical surveillance. Consistent with the
approach described by Kevin Turner above, company personnel on site,
such as supervisors, could easily record or estimate when employees
perform, or will perform, tasks requiring respirator use. Such
information could be conveyed to a company employee who tracks it.
Despite testifying that he would have a hard time tracking a greater
number of employees who may require medical surveillance if the PEL or
action level in effect at that time were lowered, Francisco Trujillo,
from Miller and Long, a company with approximately 1,500 field
employees, indicated that his company has a system that monitors and
sends emails when employees are due for another medical examination
(Document ID 3585, Tr. 3008-3010). OSHA sees no reason why this system
could not be applied to larger numbers of employees, and this shows
that it is possible for large companies to track exposures for numerous
employees. Tracking exposures or days of respirator use will likely be
easier for smaller companies who have fewer employees to track; OSHA
estimates from existing data that approximately 93 percent of
construction companies covered by the respirable crystalline silica
standard have fewer than 20 employees (see Chapter III of the FEA). In
addition, compliance officers would be able to determine if employees
were exposed for 30 or more days a year but not offered medical
surveillance by questioning employees about how often they engage in
tasks that require respirator use for that employer.
    Fann Contracting asked how a trigger for medical surveillance would
apply to employees, such as heavy machine operators, who may briefly
use respirators, such as when outside a cab for 30 minutes (Document ID
2116, Attachment 1, p. 3). OSHA clarifies that if an employee is
required to wear a respirator at any time during a given day, whether
to comply with the specified exposure control methods in paragraph (c)
or to limit exposure to the PEL under the construction standard for
respirable crystalline silica, that day counts toward the 30-day
threshold.
    Commenters also questioned the appropriateness of a 30-day
exposure-duration trigger for construction. For example, American
Society of Safety Engineers (ASSE) voiced concerns about the standard
not addressing temporary employees who are continually exposed from job
to job but may never stay with an employer for a full 30 days (Document
ID 2339, p. 5). Conversely, CISC questioned why OSHA diverged from the
ASTM exposure-duration trigger of 120 days, which would reduce the need
to make medical surveillance available for short-term employees, and
stated that OSHA needed to explain how this would improve the health of
employees (Document ID 2319, p. 118; 1504, pp. 4-5). Members of the
ASTM committee that developed the ASTM E 2625-09 standard testified
that a 120-day exposure-duration trigger was selected so that employers
did not have to provide medical surveillance to transient employees and
that even a trigger of less than 90 days was considered but would have
resulted in too much pressure and cost for employers because of the
transient nature of construction work (Document ID 3580, Tr. 1452-1453;
3585, Tr. 2919-2920).
    OSHA understands that offering medical surveillance for a transient
workforce may be challenging, especially for small companies. However,
the requirement to offer periodic medical examinations every three
years rather than annually will reduce the cost and burden of providing
such examinations considerably (see Chapter V of the FEA). OSHA finds
both the 120-day exposure-duration trigger (in the ASTM standards) and
the 90-day trigger (considered by the ASTM committee) overly exclusive
and insufficiently protective. Under those longer triggers, many short-
term employees (i.e., those doing tasks requiring respirator use or
otherwise exposed above the PEL for 30 or more days a year but
nonetheless exposed for less than 90 days with the same employer) would
be deprived of the health benefits of medical surveillance, such as
early detection of disease, despite being at risk due to repeated
exposures with different employers. As noted above, the health effects
of respirable crystalline silica are most likely to occur as a result
of repeated exposures. OSHA concludes that a 30-day exposure-duration
trigger strikes a reasonable balance between the administrative burden
of offering medical surveillance to all employees, many of whom may not
be further exposed or only occasionally exposed, and the need for
medical surveillance for employees who are regularly exposed and more
likely to experience adverse health effects. The 30-day

trigger is also administratively convenient insofar as it is consistent
with OSHA standards for construction, including asbestos (29 CFR
1926.1101), cadmium (29 CFR 1926.1127), chromium (VI) (29 CFR
1926.1126), and lead (29 CFR 1926.62).
    Commenters also raised other issues regarding the 30-day exposure-
duration trigger that could apply to both the general industry and
maritime standard and the construction standard. One concern was that
inclusion of a 30-day trigger would result in discriminatory actions by
employers in order to avoid offering medical surveillance. For example,
Dr. Daniel Anna, Vice President of AIHA, was concerned that employers
might refuse to hire someone approaching 30 days of exposure (Document
ID 3578, Tr. 1048-1049); BAC also expressed concerns about employers
terminating employees approaching their 30th day of exposure (Document
ID 4219, p. 29). In addition, BAC noted that employers rotating
employees to maintain employee exposure below 30 days might result in
more employees being exposed to silica (Document ID 2329, p. 8).
    Comments indicating that an employer might refuse to hire employees
approaching their 30th day of exposure are based on an interpretation
that medical surveillance is triggered by a total of 30 days of
exposure per year with any employer. Such an interpretation was
conveyed by the Shipbuilders Council of America and ASSE who commented
that employers would need to know employee exposures with past
employers when determining total days of exposure above the PEL
(Document ID 2255, p. 3; 3578, Tr. 1048). That is not OSHA's intent,
and OSHA clarifies that exposures occurring with past employers do not
count towards the 30-day-per-year exposure-duration trigger with the
current employer (i.e., the trigger is for employment with each
particular employer). However, the 30-day-per-year exposure-duration
trigger would apply when an employer hires a particular employee for
more than one short-term assignment during a year, totaling 30 days or
more. An advantage of not considering total exposures with all
employers in triggering medical surveillance is that it avoids creating
an incentive not to hire. With regard to comments about possible
discriminatory practices (e.g., termination before the 30th day) or
rotating employees to avoid medical surveillance, OSHA rejects the
reasoning that employers will base employment and placement decisions
on the 30-day exposure-duration trigger because the cost of medical
examinations is modest (i.e., the FEA estimates the average cost of
each medical examination at approximately $400 every three years).
    Charles Gordon suggested that employers give each departing
employee a card indicating the number of days they were exposed above
the trigger point so that future employers would have a better idea if
the employee was eligible for another medical examination based on 30
days of exposure (Document ID 4236, pp. 3-4). Such a record of past
exposure with any prior employer is not necessary because of OSHA's
decision to not consider exposures with past employers when triggering
medical surveillance. Requiring employers to record exposures with past
employers and to give employees a card indicating the number of days
they were exposed above the trigger point increases recordkeeping and
paperwork burdens for employers. It also imposes a burden on employees
because it gives them an additional document that they need to
maintain. To avoid these added burdens and for the reasons previously
given for not counting exposures with other employers towards an
employee's medical surveillance requirement, OSHA rejects Mr. Gordon's
suggestion.
    NIOSH and Fann Contracting questioned the 30-day-per-year exposure-
duration trigger because employees who have been exposed to silica for
years, but are not currently exposed 30 days per year, would be at risk
of developing lung diseases (Document ID 2116, Attachment 1, p. 41;
2177, Attachment B, pp. 39-40). NIOSH recommended that medical
surveillance continue after an employee is no longer exposed to
respirable crystalline silica but continues to work for the same
employer (Document ID 2177, Attachment B, p. 39). James Schultz, safety
director at Navistar Waukesha Foundry and representing the Wisconsin
Coalition for Occupational Safety and Health (WisCOSH), testified that
medical surveillance should continue after employees have left ``this
type of work environment'' (Document ID 3586, Tr. 3200-3201). However,
NIOSH also stated that considerations for continued medical
surveillance include the number of years an employee was required to be
monitored and if the employee is showing signs of silica-related
illness (Document ID 2177, Attachment B, p. 39).
    OSHA agrees with NIOSH that silica is retained in the lungs and can
cause progressive damage after exposures end. However, the lack of
clear criteria in the record for determining when continued medical
surveillance would be beneficial precludes OSHA from mandating
continued medical surveillance after exposure ends. In addition, OSHA
policy is clear that requirements are imposed on current employers. In
the benzene standard, OSHA articulated that policy in deciding not to
mandate continued medical surveillance for employees who are no longer
exposed above the trigger, noting administrative difficulties in
keeping track of employees who had moved on to other jobs (52 FR 34460,
34550 (9/11/1987)).
    CISC, American Subcontractors Association, OSCO Industries, and
Holes Incorporated questioned why medical surveillance is needed for
younger employees when respirable crystalline silica-related diseases
take years to develop (Document ID 1992, p. 11; 2187, p. 7; 2319, pp.
116-117; 3580, Tr. 1471). CISC recommended that OSHA trigger medical
surveillance after a minimum duration of exposure or when a silica-
related disease is diagnosed. In contrast, Andrew O'Brien, Vice
President of Safety and Health at Unimin Corporation and representing
NISA, emphasized the importance of establishing a baseline for future
measurement (Document ID 3577, Tr. 570). When asked if age or duration
of exposures should be considered in determining frequency of medical
surveillance, Dr. Laura Welch, occupational physician with BCTD,
responded:

. . . we're looking at different disease outcomes. If we were only
concerned about silicosis, you could probably . . . make that
argument, but silica exposure also causes [chronic obstructive
pulmonary disease], and that has an earlier onset and . . . it's
good to have a baseline of a couple of tests before someone develops
disease so you can more clearly see an early decline (Document ID
3581, Tr. 1667).

    When a BAC panel was asked if 20 years after first exposure is the
appropriate time to start medical surveillance, terrazzo worker Sean
Barret responded:

    According to their 20-year standard, you wouldn't even find out
I was sick until next year. I was sick a year ago, and it probably
showed five years before that. So, I mean, that's ludicrous
(Document ID 3585, Tr. 3055).

    OSHA agrees that employees' baseline findings are important for
future diagnoses and notes Dr. Welch's testimony that other silica-
related diseases, such as chronic obstructive pulmonary disease (COPD),
develop in shorter times than silicosis. Based on such evidence, OSHA
concludes that it is appropriate to start medical surveillance in young
or newly exposed

employees before they experience declines in health or function
associated with age or respirable crystalline silica exposure.
    Paragraph (i)(1)(ii) of the standard for general industry and
maritime (paragraph (h)(1)(ii) of the standard for construction)
requires that the medical examinations made available under the rule be
performed by a PLHCP, who is defined (see summary and explanation of
Definitions) as an individual whose legally permitted scope of practice
(i.e., license, registration, or certification) allows him or her to
independently provide or be delegated the responsibility to provide
some or all of the particular health services required by paragraph (i)
of the standard for general industry and maritime (paragraph (h) of the
standard for construction). This provision is unchanged from the
proposed rule.
    The American Public Health Association (APHA) requested changes to
the definition of PLHCP that would require the PLHCP to be licensed for
independent practice (Document ID 2178, Attachment 1, p. 5). OSHA finds
that requested change to be too restrictive. To assure competency while
providing for increased flexibility, OSHA continues to find it
appropriate to allow any professional to perform medical examinations
and procedures made available under the standard when he or she is
licensed by state law to do so. In this respect, which and how a health
care professional can function as a PLHCP under the rule may vary from
state to state depending on each state's licensing requirements and
laws governing what diagnostic examinations and procedures they are
permitted to perform. In no case, however, is the authorization in this
rule to use any PLHCP narrower or stricter than what is authorized in
the particular state where an examination occurs.
    Some commenters expressed concern about the availability of PLHCPs
or other medical professionals in certain geographical locations. For
example, Fann Contracting and the National Rural Electric Cooperative
Association commented that PLHCPs who can offer the required
examinations or occupational health resources may not be available for
employers located in rural areas or near retirement communities
(Document ID 2116, Attachment 1, p. 43; 2365, p. 10). Under the rule, a
PLHCP, as defined, does not have to be an occupational medicine
physician or even a physician to conduct the initial and periodic
examinations required by the rule, but can be any health care
professional who is state-licensed to provide or be delegated the
responsibility to provide those services. The procedures required for
initial and periodic medical examinations are commonly conducted in the
general population (i.e., medical history, physical examination, chest
X-ray, spirometry test, and tuberculosis test) by practitioners with
varying qualifications. Because medical examinations consist of
procedures conducted in the general population and because OSHA is
giving employers maximum flexibility in selecting a PLHCP who can offer
these services, OSHA intends to assure that employers will not
experience great difficulty in finding PLHCPs who are state-licensed to
provide or be delegated the responsibility to provide these services.
Even in the case of X-rays, OSHA finds that the availability of digital
X-ray technology allows for electronic submission to a remotely located
B Reader for interpretation, and thus does not expect a limited number
of B readers in a certain geographic location to be an obstacle to
employers covered by the rule.
    Initial examination. Paragraph (i)(2) of the standard for general
industry and maritime (paragraph (h)(2) of the standard for
construction) specifies that an initial (baseline) medical examination
must be made available within 30 days of initial assignment (i.e., the
day the employee starts working in a job with potential exposures above
the trigger point), unless the employee received an examination that
meets the requirements of this section within the past three years.
This provision is unchanged from the proposed rule. The requirement for
an initial examination within 30 days of assignment provides a health
baseline for future reference and lets employees know of any conditions
that could increase their sensitivity to respirable crystalline silica
exposure. For example, Dr. Tee Guidotti, an occupational medicine
physician representing the Association of Occupational and
Environmental Clinics (AOEC), testified that existing COPD may make an
individual more sensitive to respirable crystalline silica exposure
(Document ID 3577, Tr. 797-798).
    Newmont Mining Corporation, Nevada Mining Association, and
Distribution Contractors Association (DCA) questioned whether recent or
future exposures should be considered in triggering certain aspects of
the initial examination (e.g., physical examination, chest X-ray, or
pulmonary function tests) and indicated that baseline examinations
should only be required near the time when exposures begin (Document ID
1963, p. 2; 2107, p. 3; 2309, p. 5). The requirement is for employers
to offer initial examinations to employees who ``will be''
occupationally exposed to respirable silica at or above the action
level for 30 or more days a year in the standard for general industry
and maritime (paragraph (i)(1)(i)) or who ``will be'' required to use a
respirator under this section for 30 or more days per year in the
standard for construction (paragraph (h)(1)(i)). Therefore, eligibility
for medical examinations is based on expected exposure with the current
employer. These triggers apply to both initial and periodic medical
surveillance, and inclusion of the terms ``will be occupationally
exposed'' or ``will be required'' makes it clear that requirements to
offer medical surveillance are not based on past exposures. OSHA is
aware that unexpected circumstances may result in employees being
exposed more frequently than initially anticipated. In those cases,
employers should make medical surveillance available as soon as it
becomes apparent that the employee will be exposed above the
appropriate trigger point for 30 or more days per year.
    In the preamble of the Notice of Proposed Rulemaking (NPRM), OSHA
indicated that where an examination that complies with the requirements
of the standard has been provided in the past three years, an
additional initial examination would not be needed (78 FR at 56468).
Ameren agreed with OSHA's preliminary determination on this issue and
asked the Agency to verify that examinations conducted in the last
three years could be supplemented with any additional requirements of
the rule, such as tuberculosis testing (Document ID 2315, p. 4). OSHA
agrees that this is a reasonable approach. For example, if an employee
received an examination that met all the requirements of the initial
medical examination, with the exception of a tuberculosis test, within
the last three years, the employer could supplement that examination by
offering only the tuberculosis test. That same employer or a future
employer could then offer a periodic medical examination, which does
not require a tuberculosis test, three years from the last medical
examination. New hires, who received medical surveillance that met the
requirements of the respirable crystalline silica rule from a past
employer, should have a copy of the PLHCP's written medical opinion for
the employer, which the employer must ensure that the employee receives

within 30 days of the examination (paragraph (i)(6)(iii) of the
standard for general industry and maritime, paragraph (h)(6)(iii) of
the standard for construction), as proof of a current initial or
periodic medical examination that met the requirements of this section
(see example of the PLHCP's written medical opinion for the employer in
Appendix B). If a newly hired employee eligible for medical
surveillance presents proof of an examination that met the requirements
of the rule, the employer's obligation is to offer the periodic
examination required by paragraph (i)(3) of the standard for general
industry and maritime (paragraph (h)(3) of the standard for
construction) within three years of the previous examination.
    Commenting on the three year period in which the result of a prior
examination can substitute for a new initial (baseline) examination,
APHA, Collegium Ramazzini, and the American Federation of State, County
and Municipal Employees (AFSCME) opined that three years between
examinations is an excessive time period because it does not provide
for an adequate baseline; Collegium Ramazzini further commented that
medical findings and medical or work histories can change in three
years and that spirometry performed at other locations does not provide
an adequate baseline (Document ID 2178, Attachment 1, p. 4; 3541, pp.
4-5; 4203, p. 6). Dr. Celeste Monforton, from George Washington
University School of Public Health, agreed with APHA (Document ID 3577,
Tr. 846). OSHA disagrees. The three-year interval is consistent with
the frequency of periodic examinations, and the reasons for this
interval, such as the typical slow progression of respirable
crystalline silica-related diseases, are discussed below.
    The American Foundry Society (AFS) supported the 30-day period for
offering medical surveillance, stating that it addressed the turnover
rates in its industry because employees who work 30 days are likely to
continue their employment (Document ID 2379, Appendix 1, p. 71). AESC
requested that OSHA allow medical examinations to be provided within 90
days of assignment to address the turnover rate in its industry
(Document ID 2344, p. 2). The National Stone, Sand and Gravel
Association (NSSGA) noted difficulties in scheduling medical
examinations within 30 days in remote locations because testing vans
that offer medical examinations might not be available within that time
period (Document ID 3583, Tr. 2316-2317). Because a 30-day period for
offering medical examinations is reasonable for AFS, which represents
an industry with high turnover rates, OSHA concludes that a 30-day
period should be reasonable in most general industry settings. OSHA
does not agree with AESC that the period to offer medical surveillance
should be extended to 90 days in the standard for general industry and
maritime. That longer time period to offer medical surveillance would
exclude and leave unprotected many employees who may be exposed to
significant amounts of silica while working short-term assignments, for
periods up to 90 days, for numerous companies within the same industry.
    Representatives from the construction industry also commented on
the 30-day period to offer medical surveillance. BAC and BCTD
recommended that medical examinations be made available as soon as
practicable, instead of within 30 days after assignment, in the
construction industry because it would be difficult for employers to
predict if an employee would be exposed for 30 days or more during the
upcoming year, and it could encourage employers to terminate employees
before the 30-day period ends (Document ID 4219, p. 29; 4223, p. 125).
Fann Contracting suggested that a better trigger would be after the
employee has been exposed for 30 days instead of within the first 30
days of assignment (Document ID 2116, Attachment 1, p. 43).
    OSHA rejects this reasoning, and is maintaining the requirement to
offer medical surveillance within 30 days of assignment for the
construction standard. The requirement better assures that medical
examinations will be offered within a reasonable time period than
allowing the employer to offer them ``as soon as practicable.'' As
noted above, employers can determine who will be eligible for medical
surveillance based on required respirator use under Table 1 or similar
task-based approaches. Even at the time of initial assignment, OSHA
expects that employers will know the tasks that the employee will be
performing, and in the case of short-term employees, the approximate
duration the employee will be with the company. In addition,
terminating employees to avoid offering medical surveillance would not
be cost effective because the employer would incur more costs from
constantly having to train new employees.
    The Precast/Prestressed Concrete Institute commented that local
union halls from which they hire employees and the Americans with
Disability Act may prohibit pre-hire medical testing (Document ID 2276,
p. 10). National Electrical Contractors Association expressed concern
about economic burdens associated with pre- and post-employment medical
evaluations in transient or temporary employees (Document ID 2295, p.
2). OSHA clarifies that no pre-hire or post-employment testing is
required in the respirable crystalline silica rule, which requires that
medical examinations related to respirable crystalline silica exposure
be offered within 30 days after initial assignment to employees who
will meet the trigger for medical surveillance.
    Contents of initial medical examination. Paragraphs (i)(2)(i)-(vi)
of the standard for general industry and maritime (paragraphs
(h)(2)(i)-(vi) of the standard for construction) specify that the
initial medical examination provided by the PLHCP must consist of: A
medical and work history; a physical examination with special emphasis
on the respiratory system; a chest X-ray; a pulmonary function test; a
latent tuberculosis test; and other tests deemed appropriate by the
PLHCP. Special emphasis must be placed on the portions of the medical
and work history focusing on exposure to respirable crystalline silica,
dust or other agents affecting the respiratory system, any history of
respiratory system dysfunction (including signs and symptoms, such as
shortness of breath, coughing, and wheezing), any history of
tuberculosis, and current or past smoking. The only changes from the
proposed rule are reflected in paragraphs (i)(2)(iii) and (iv) of the
standard for general industry and maritime (paragraphs (h)(2)(iii) and
(iv) of the standard for construction), and those revisions are
discussed below.
    OSHA received a range of comments related to the contents of the
initial examination. Some stakeholders, including NIOSH and commenters
representing the medical community, labor unions, and industry,
supported the contents of medical surveillance that OSHA proposed,
though some wanted to expand the contents, as addressed below (e.g.,
Document ID 2175, p. 6; 2177, Attachment B, pp. 38-39; 2282, Attachment
3, p. 19; 2336, p. 12; 2371, Attachment 1, p. 43; 3589, Tr. 4205; 4204,
p. 82). Further, the contents of medical surveillance in this standard
are fairly consistent with the recommendations in occupational health
programs, such as those by NISA and NSSGA (Document ID 2195, pp. 40-41;
2327, Attachment 1, p. 23).
    However, not all stakeholders agreed that the list of proposed
initial examination contents was appropriate. For example, Fann
Contracting favored

limiting the contents of medical examinations to X-rays, while Dal-Tile
Corporation, the 3M Company, and the Tile Council of North America
indicated that requirements for medical examinations under the
respiratory protection standard were sufficient (Document ID 2116,
Attachment 1, p. 37; 2147, p. 3; 2313, p. 7; 2363, pp. 5-6). Similarly,
Nevada Mining Association commented that the need to conduct physical
examinations, X-rays, or pulmonary function testing should be left to
the discretion of the PLHCP (Document ID 2107, pp. 3-4). Newmont Mining
also said that one or more of these tests should be at the discretion
of the PLHCP (Document ID 1963, pp. 2-3).
    OSHA finds that X-rays alone are not sufficient because, as
explained in more detail below, some employees may have symptoms or
abnormal lung function that are not detected by X-ray but may become
evident by other tests, such as spirometry. The Agency also finds that
the evaluations offered under the respiratory protection standard are
insufficient because the information gathered under that standard is
limited and may not involve examinations, while the respirable
crystalline silica rule requires examinations that include objective
measures, such as physical examinations, spirometry testing and X-rays,
that may detect early disease in asymptomatic employees. In addition,
OSHA does not agree that all required tests should be left to the
discretion of the PLHCP because the Agency has determined that
employees who must be offered medical surveillance are at risk of
developing respirable crystalline silica-related diseases, and the
required tests are the minimum tests needed to screen for those
diseases. Therefore, OSHA concludes that limiting medical surveillance
to only X-rays, the evaluations performed under the respiratory
protection standard, or only tests selected by the PLHCP is not
sufficiently protective.
    The first item required as part of the initial medical examination
is a medical and work history, with emphasis on: Past, present, and
anticipated exposure to respirable crystalline silica, dust, and other
agents affecting the respiratory system; any history of respiratory
system dysfunction, including signs and symptoms of respiratory disease
(e.g., shortness of breath, cough, wheezing); history of tuberculosis;
and smoking status and history (paragraph (i)(2)(i) of the standard for
general industry and maritime, paragraph (h)(2)(i) of the standard for
construction). OSHA is requiring medical and work histories because
they are an efficient and inexpensive means for collecting information
that can aid in identifying individuals who are at risk due to
hazardous exposures (Document ID 1505, p. 2; 1517, p. 25). Recording of
symptoms is important because, in some cases, symptoms indicating onset
of disease can occur in the absence of abnormal laboratory test
findings (Document ID 1517, p. 25).
    Because symptoms may be the earliest sign of disease and to allow
for consistent and comprehensive data collection, Collegium Ramazzini
recommended that an appendix with a standardized questionnaire be
included; it also recommended that the questionnaire address non-
respiratory effects, such as renal disease and connective tissue
disorders (Document ID 3541, pp. 3, 6). While not going as far as this
recommendation, OSHA includes in the rule an appendix for medical
surveillance (Appendix B), which gives PLHCPs detailed information on
what is to be collected as part of the medical history. The appendix
recommends collecting information on renal disease and connective
tissue disorders. OSHA intends for this approach to allow PLHCPs to
easily standardize their method for gathering information for work and
medical histories related to respirable crystalline silica exposure.
    Newmont Mining and Nevada Mining Association objected to a
requirement for a medical and work history, asserting that a personal
medical history is not related to silica exposure (Document ID 1963, p.
2; 2107, p. 3). Commenters, including DCA and International Brotherhood
of Teamsters, objected to employees revealing medical and work history
information not related to respirable crystalline silica exposure
because of privacy concerns (e.g., Document ID 2309, p. 5; 2318, pp.
13-14). Retired foundry employee, Allen Schultz, representing WisCOSH,
expressed concern that information, such as smoking history, could be
used against employees (Document ID 3586, Tr. 3255). As noted above, a
purpose of medical surveillance is to inform employees if they may be
at increased risk of adverse effects from respirable crystalline silica
exposure. Personal habits, such as smoking, could lead to compromised
lung function or increased risk of lung cancer, and exposure to
respirable crystalline silica could compound those effects (see Section
V, Health Effects). Collecting information, such as smoking habits and
related medical history, allows the PLHCP to warn employees about their
increased risks from exposure to respirable crystalline silica so
employees can make informed health decisions.
    As discussed below, OSHA is addressing employee privacy issues by
reducing the information to be included in the PLHCP's written medical
opinion for the employer without the employee's permission (paragraphs
(i)(6)(i)(A)-(C) of the standard for general industry and maritime and
paragraphs (h)(6)(i)(A)-(C) of the standard for construction); under
those paragraphs, the only medically related information that is to be
reported to the employer without authorization from the employee is
limitations on respirator use. Personal habits, such as smoking, are
not included in the medical opinion for the employer. Therefore,
employees' privacy will not be compromised as a result of the
information collected as part of the exposure and medical history.
    The second item required as part of the initial medical examination
is a physical examination that focuses on the respiratory system
(paragraph (i)(2)(ii) of the standard for general industry and
maritime, paragraph (h)(2)(ii) of the standard for construction), which
is known to be susceptible to respirable crystalline silica toxicity.
OSHA finds that aspects of the physical examination, such as visual
inspection, palpation, tapping, and listening with a stethoscope, allow
the PLHCP to detect abnormalities in chest shape or lung sounds that
are associated with compromised lung function (Document ID 1514, p. 74;
1517, pp. 26-27). Dr. Michael Fischman, occupational and environmental
physician/toxicologist and professor at the University of California,
representing ACOEM, strongly endorsed a physical examination and noted
that another valuable aspect is that it allows the employee to have a
face-to-face interaction with the clinician to talk about symptoms or
other concerns (Document ID 3577, Tr. 767). OSHA agrees and concludes
that the physical examination is necessary.
    The third item required as part of the initial medical examination
is a chest X-ray, specifically a single posteroanterior radiographic
projection or radiograph of the chest at full inspiration recorded on
either film (no less than 14 x 17 inches and no more than 16 x 17
inches) or digital radiography systems, interpreted and classified
according to the International Labour Office (ILO) International
Classification of Radiographs of Pneumoconioses by a NIOSH-certified B
Reader (paragraph (i)(2)(iii) of the standard for general industry and
maritime, paragraph (h)(2)(iii) of the standard for construction). The
proposed rule

specified only film X-rays but would have allowed for an equivalent
diagnostic study, such as digital X-rays; OSHA also sought comment on
whether computed tomography (CT) or high resolution computed tomography
(HRCT) scans should be considered equivalent diagnostic tests (78 FR at
56469-56470). As discussed in greater detail below, OSHA received many
comments on the proposed provision, and in response to those comments,
the current provision differs substantially from the proposed rule in
two main ways. First, the rule now specifically allows for chest X-rays
to be recorded on either film or digital radiography systems. Second,
the rule does not allow for an ``equivalent diagnostic study.''
    Medical experts including ACOEM, the American Thoracic Society
(ATS), and NIOSH recommend X-rays as part of medical examinations for
employees exposed to respirable crystalline silica (e.g., Document ID
1505, p. 2; 2175, p. 6; 2177, Attachment B, pp. 38-39). The initial X-
ray provides baseline data against which to assess any subsequent
changes. An initial chest X-ray can be useful for diagnosing silicosis
and for detecting mycobacterial disease (e.g., active pulmonary
tuberculosis, which employees with latent tuberculosis infections and
exposed to respirable crystalline silica are at greater risk of
developing (Document ID 1514, pp. 75, 100). X-rays are important
because the findings can lead to the initiation of employment choices
that can reduce exposures to respirable crystalline silica and might
decrease the risk of silicosis progression or allow for treatment of
mycobacterial infections (Document ID 1505, p. 3).
    As noted above, OSHA proposed that the required chest X-ray be
interpreted and classified according to ILO International
Classification of Radiographs of Pneumoconiosis by a NIOSH-certified B
Reader. The ILO system was designed to assess X-ray and digital
radiographic image quality and to describe radiographic findings of
pneumoconiosis in a simple and reproducible way by comparing an
employee's X-ray to a standard X-ray to score opacities according to
shape, size, location, and profusion (Document ID 1475, p. 1; 1511, pp.
64-68; 1514, pp. 77-78). A NIOSH-certified B Reader is a physician who
has demonstrated competency in the ILO classification system by passing
proficiency and periodic recertification examinations (Document ID
1498, p. 1). The NIOSH certification procedures were designed to
improve the proficiency of X-ray and digital radiographic image readers
and minimize variability of readings.
    In 2011, the ILO made standard digital radiographic images
available and published guidelines on the interpretation and
classification of digital radiographic images (Document ID 1475). The
guidelines included requirements for display monitors. NIOSH also
published guidelines for conducting digital radiography and displaying
digital radiographic images in a manner that will allow for
classification according to ILO guidelines (Document ID 1513). Based on
these developments, OSHA stated in the preamble of the NPRM that
digital X-rays could now be evaluated according to the same guidelines
as film X-rays and could therefore be considered equivalent diagnostic
tests. The Agency also noted several advantages of digital X-rays:
Compared to film X-rays, digital imaging systems offer more consistent
image quality, faster results, increased ability to share images with
multiple readers, simplified storage of images, and reduced risk for
technicians and the environment due to the elimination of chemicals for
developing film (Document ID 1495, p. 2).
    Commenters, such as Collegium Ramazzini, NIOSH, and the Dow
Chemical Company, agreed with OSHA that digital radiographic images are
equivalent to conventional X-rays; NIOSH and Dow Chemical suggested
OSHA clarify that the proposed requirement for chest X-rays may be
satisfied either with conventional film-based technology or with
digital technology; and NIOSH and Collegium Ramazzini referred OSHA to
an interim final regulation for coal miners that allows for digital
technology (Document ID 2177, Attachment B, pp. 40-41; 2270, p. 13;
3541, p. 7). After reviewing the record evidence on this issue, OSHA
reaffirms its preliminary conclusion that X-rays recorded on digital
radiography systems are equivalent to those recorded on film.
Therefore, OSHA has revised paragraph (i)(2)(iii) of the standard for
general industry and maritime (paragraph (h)(2)(iii) of the standard
for construction) to indicate that X-rays can be recorded on either
film or digital systems, using language that is consistent with that in
the interim final regulation for coal miners (42 CFR part 37.2 (10-1-13
Edition)).
    NSSGA commented that good quality digital images reproduced on film
should also be considered acceptable as equivalent to X-rays (Document
ID 2327, Attachment 1, p. 23). OSHA disagrees. The Agency does not
recommend classification using hard copies printed from digital images
because a 2009 study by Franzblau et al. indicates that they give the
appearance of more opacities compared to films or digital images
(Document ID 1512). OSHA does not find hard copy printouts of digital
images equivalent to conventional X-rays. Consequently, classification
through the use of hard copies printed from digital images may not be
used to satisfy the requirement for chest X-rays.
    As indicated above, the proposed rule called for the chest X-ray to
be interpreted and classified by a NIOSH-certified B reader. A number
of commenters offered opinions on this requirement. For example, Dow
Chemical urged OSHA to allow board certified radiologists to interpret
the X-rays because it claimed that insufficient numbers of B Readers
would lead to a backlog of X-ray interpretation that would make it
impossible for B Readers to get their reports back to PLHCPs within the
required 30 days (Document ID 2270, p. 9). Other representatives from
industry, such as the Mason Contractors Association of America, ARMA,
and the North American Insulation Manufacturers Association, expressed
similar concerns about numbers of B Readers (e.g., Document ID 2286,
pp. 2-3; 2291, p. 26; 2348, Attachment 1, pp. 39-40).
    The rulemaking record contains ample evidence of sufficient numbers
of B Readers and the value of B Reader interpretation according to ILO
methods. CISC and NIOSH estimated demands on B Readers based on OSHA's
estimate in the preamble of the NPRM that 454,000 medical examinations
would be required in the first year after the rule is promulgated (78
FR at 56468). Based on the 242 B Readers accounted for as of February
12, 2013 (78 FR at 56470), CISC estimated 1,876 chest X-rays for each B
Reader, requiring each B Reader to interpret more than five chest X-
rays per day, which CISC claimed would result in a backlog (Document ID
2319, p. 118). However, Dr. David Weissman, Director of NIOSH's
Division of Respiratory Disease Studies, indicated that a B Reader can
easily classify 10 images in an hour (Document ID 3579, Tr. 196,
Attachment 2, p. 1). NIOSH estimated that a B Reader working 1 hour per
day, 5 days per week, 50 weeks per year can classify 2,500 images and
that 182 B Readers working a minimum of 1 hour per day and 50 weeks per
year would be needed to classify X-rays for 454,000 employees (Document
ID 4233, Attachment 1, p. 40). As of May 19, 2014, there were 221
certified B Readers in the United States, an adequate number to meet
the demands for the respirable crystalline silica rule (Document ID
3998, Attachment 15, p.

2). Based on the new triggers and more recent data on turnover rates,
OSHA estimates that approximately 520,000 medical examinations will be
required in the first year after the rule is promulgated. Using Dr.
Weissman's assumptions, OSHA estimates that 221 B Readers would need to
spend less than 1 hour a day to classify X-rays for 520,000 employees.
    Dr. Weissman testified that the number of B Readers is driven by
supply and demand created by a free market and that many physicians
choose to become B Readers based on demands for such services (Document
ID 3579, Tr. 197-198, Attachment 2, p. 1). He went on to state that
NIOSH provides several pathways for physicians to become B Readers,
such as free self-study materials by mail or download and free B Reader
examinations. In addition, courses and examinations for certification
are offered for a fee every three years through the American College of
Radiology. Dr. Robert Cohen, pulmonary physician and clinical professor
at the University of Illinois, representing ATS, agreed that NIOSH is
able to train enough B Readers to handle any potential increase in
demand (Document ID 3577, Tr. 777). Moreover, even if B Readers are
scarce in certain geographical locations, digital X-rays can easily be
transmitted electronically to B Readers located anywhere in the U.S.
(Document ID 2116, Attachment 1, p. 43; 3580, Tr. 1471-1472; 3585, Tr.
2887; 2270, p. 13; 2195, p. 44; 3577, Tr. 817-818). Based on this
information, OSHA concludes that numbers of B Readers in the U.S. are
adequate to interpret X-rays conducted as part of the respirable
crystalline silica rule.
    Some commenters questioned the value of requiring B Readers. Dow
Chemical claimed that board certified radiologists are able to provide
interpretations of X-rays that are consistent with those of B Readers
and that such an approach is consistent with that of the OSHA Asbestos
standard (29 CFR 1910.1001, Appendix E) (Document ID 2270, pp. 9-10).
Dow Chemical also stated that digital radiography has improved
interpretation accuracy for radiologists who are not B Readers.
American Road and Transportation Builders Association (ARTBA) commented
that inadequate numbers of B Readers could result in misinterpretations
of X-rays. It also cited a study by Gitlin et al. (2004), which it
interpreted as showing that B Readers can be biased by exposure
information; according to ARBTA, the study reported that B Readers
hired for asbestos litigation cases read 95.9 percent of X-rays as
positive, while independent, blinded B readers only read 4.5 percent of
those X-rays as positive (Document ID 2245, pp. 2-3).
    Based on record evidence, OSHA finds that the requirement for B
Readers to demonstrate proficiency in ILO methods results in more
consistent X-ray interpretation. For example, guidelines by the World
Health Organization (WHO) acknowledge the value of consistent, high-
quality X-rays for reducing interpretation variability and note that B
Reader certification may also improve consistency of X-ray
interpretation (Document ID 1517, p. 21). Robert Glenn, Certified
Industrial Hygienist representing the Brick Industry Association and
previously in charge of the B Reader program at NIOSH, said he thought
the reduced variability (i.e., lower prevalence of small opacities
graded 1/0 or greater in unexposed populations) in the U.S. compared to
Europe in a study by Meyer et al. (1997) could be attributed to the
success of the B Reader program (Document ID 3577, Tr. 668, 670, 682;
3419, p. 404). Dr. James Cone, occupational medicine physician at the
New York City Department of Health, stated that development of ILO
methods for evaluating pneumoconiosis by chest X-ray has led to greater
precision and sensitivity. Dr. Cone gave the example that two B Readers
who evaluated X-rays performed on foundry employees as part of a NIOSH
Health Hazard Evaluation identified six cases of X-rays and
occupational history consistent with silicosis that had been classified
as normal by company physicians (Document ID 2157, pp. 4-5). Based on
the record evidence demonstrating the value of B Reader certification,
OSHA rejects the suggestion that the standard should allow X-ray
interpretation by board-certified radiologists.
    The evidence discussed above supports OSHA's conclusions that
adequate numbers of B Readers are available locally or by electronic
means to interpret chest X-rays of respirable crystalline silica-
exposed employees and that B Reader certification improves the quality
of X-ray interpretation. OSHA concludes that standardized procedures
for the evaluation of X-ray films and digital images by certified B
Readers is warranted based on the seriousness of silicosis and is
therefore retaining that requirement in the rule.
    OSHA noted in the preamble for the NPRM that CT or HRCT scans could
be considered ``equivalent diagnostic studies.'' CT and HRCT scans are
superior to chest X-ray in the early detection of silicosis and the
identification of progressive massive fibrosis. However, CT and HRCT
scans have risks and disadvantages that include higher radiation doses
and current unavailability of standardized methods for interpreting and
reporting the results (78 FR at 56470). Because of these concerns, OSHA
specifically sought comment on whether CT and HRCT scans should be
considered equivalent diagnostic studies under the rule, and a number
of stakeholders provided comments on this issue.
    In its prehearing comments, ATS stated that despite the lack of
standardized interpretation and reporting methods, CT or HRCT are
reasonable ``equivalent diagnostic studies'' to standard chest X-rays
because they are more sensitive than X-rays for early detection of
diseases, such as silicosis and lung cancer; however, the group's
representative, Dr. Robert Cohen, later testified that HRCT is not
ready as a screening technique but is a useful diagnostic tool
(Document ID 2175, p. 6; 3577, Tr. 825). USW noted that interpretation
methods are being developed for the evaluation of pneumoconiosis by CT
scan and suggested approaches for the use of low dose CT (LDCT) scans
to evaluate silicosis and lung cancer in some employees (Document ID
4214, pp. 9-12).
    Physicians, such as those representing ACOEM, Collegium Ramazzini,
and NIOSH, did not consider CT or HRCT to be equivalent diagnostic
studies because of the lack of a widely-accepted standardized system of
interpretation, such as the ILO method (e.g., Document ID 2080, pp. 7-
8; 2177, Attachment B, p. 40; 3541, p. 7). In addition, NIOSH, APHA,
Edison Electric Institute (EEI), Collegium Ramazzini, and ACOEM
indicated the higher radiation doses received from CT and HRCT scans
make it inappropriate to consider these methods equivalent to X-rays
(Document ID 2177, Attachment B, p. 40; 2178, Attachment 1, p. 6; 2357,
pp. 34-35; 3541, p.7; 3577, Tr. 768).
    NIOSH and Collegium Ramazzini also commented on the increased
sensitivity of CT scans in detecting abnormalities that require follow-
up, which they cited as another reason why CT scans should not be
considered equivalent to X-rays (Document ID 2177, Attachment B, p. 40;
3541, p. 7). NIOSH said the abnormalities can suggest lung cancer, but
most are found to be ``false positives'' (Document ID 2177, Attachment
B, p. 40). Detection of abnormalities that might suggest cancer can
lead to anxiety in patients; it can also lead to follow-up with more
imaging tests that increase radiation exposures or invasive biopsy
procedures

that have a risk of complications (Document ID 2177, Attachment B, p.
40; 3978, pp. 2423, 2427). Commenters also noted that CT scans cost
more than X-rays (Document ID 2177, Attachment B, p. 40; 2178,
Attachment 1, p. 6; 3541, p. 7). In addition, Collegium Ramazzini
stated that chest X-rays are readily accessible in most cases, but
availability of CT scanning is more limited, especially in rural areas
(Document ID 3541, p. 7).
    ACOEM, NIOSH, APHA, NSSGA, EEI, and AFL-CIO stated that CT scans
are appropriate in some cases, such as a part of follow-up examinations
or if recommended by the PLHCP (Document ID 2080, p. 8; 2177,
Attachment B, pp. 40-41; 2178, Attachment 1, p. 6; 2327, Attachment 1,
p. 26; 2357, pp. 34-35; 4204, p. 82). Dr. David Weissman and Dr.
Rosemary Sokas, occupational physician from Georgetown University,
representing APHA, indicated that if an employee happens to have had a
CT scan that was conducted as part of a clinical workup or diagnosis,
it should be accepted in place of X-rays (Document ID 3577, Tr. 792;
3579, Tr. 256).
    After reviewing the record on this issue, OSHA has determined that
CT or HRCT scans should not be considered ``equivalent diagnostic
studies'' to conventional film or digital chest X-rays for screening of
silicosis because of higher radiation exposures, lack of a standardized
classification system for pneumoconiosis, increased false positive
findings, higher costs, and limited availability in some areas. OSHA
also agrees with commenters that CT scans may be useful for follow-up
purposes, as determined on a case-by-case basis by the PLHCP. For
example, the PLHCP could request a CT scan to diagnose possible
abnormalities detected by X-ray or other testing done as part of
surveillance, and the rule gives the PLHCP this option (paragraph
(i)(2)(vi) of the standard for general industry and maritime, paragraph
(h)(2)(vi) of the standard for construction). However OSHA does not
agree that a CT scan conducted within the past three years can meet the
requirement for an X-ray because the CT scan cannot be evaluated
according to ILO methods.
    OSHA also received comments on the use of CT scans to screen for
lung cancer, and those comments are discussed below, as part of the
Agency's discussion of additional tests that commenters proposed for
inclusion in medical examinations.
    In sum, unlike the proposed rule, paragraph (i)(2)(iii) of the
standard for general industry and maritime (paragraph (h)(2)(iii) of
the standard for construction) specifically allows for digital X-rays,
but does not allow for an equivalent diagnostic study. The rule was
revised to allow for digital radiography because OSHA determined that
digital X-rays are equivalent to film X-rays. The rule was also revised
to remove the allowance for equivalent diagnostic studies because OSHA
determined that CT scans are not equivalent to X-rays for screening
purposes and no other imaging tests are equivalent to film or digital
X-rays interpreted by ILO methods at this time. The provision for X-
rays does not contain any other substantive changes compared to the
proposed provision.
    The fourth item required as part of the initial medical examination
is a pulmonary function test, including forced vital capacity (FVC),
forced expiratory volume in one second (FEV1), and
FEV1/FVC ratio, administered by a spirometry technician with
a current certificate from a NIOSH-approved spirometry course
(paragraph (i)(2)(iv) of the standard for general industry and
maritime, paragraph (h)(2)(iv) of the standard for construction). FVC
is the total volume of air exhaled after a full inspiration,
FEV1 is the volume of air exhaled in the first second, and
the FEV1/FVC ratio is the speed of expired air (Document ID
3630, p. 2). OSHA proposed the inclusion of pulmonary function testing
(i.e., spirometry, as required by this rule) because it is useful for
obtaining information about the employee's lung capacity and expiratory
flow rate and for determining baseline lung function status against
which to assess any subsequent lung function changes.
    Some industry representatives, such as Fann Contracting and CISC,
opposed the requirement for spirometry testing because reduced
pulmonary function can be related to smoking or exposures other than
respirable crystalline silica (Document ID 2116, Attachment 1, Page 39;
2319, pp. 118-119). CISC further commented that OSHA did not address
statements in the ASTM standard about the non-specificity of lung
function changes to respirable crystalline silica exposure, and a lack
of evidence that routine spirometry is useful for detecting respirable
crystalline silica-related diseases in early stages.
    In contrast, commenters, such as Collegium Ramazzini and NIOSH,
noted that spirometry is useful for detecting lung function changes
associated with COPD, a disease outcome related to respirable
crystalline silica exposure (Document ID 3541, p. 8; 3579, Tr. 255).
ACOEM and Collegium Ramazzini explained that respirable crystalline
silica exposures can result in lung function changes in the absence of
radiological abnormalities, and spirometry is important for detecting
those changes in the early stages of disease; ACOEM further commented
that early detection of abnormal lung function is important to fully
assess employees' health and apply protective intervention methods
(Document ID 2080, p. 8; 3541, p. 8).
    ASSE and some industry representatives, including Newmont Mining,
NISA and AFS, also supported spirometry testing (e.g., Document ID
1963, pp. 2-3; 2339, p. 9; 2379, Appendix 1, p. 70; 4208, p. 22). NISA
includes spirometry testing as part of its occupational health program
for respirable crystalline silica-exposed employees; it emphasized that
spirometry testing: (1) Allows for early detection and measurement of
severity of lung function loss, the most direct symptom of silicosis or
other nonmalignant respiratory disease, and (2) is useful for
determining an employee's ability to safely wear a negative pressure
respirator (Document ID 4208, p. 22).
    After reviewing the comments submitted, OSHA reaffirms that
spirometry testing should be included in the rule. OSHA concludes that
even though declines in lung function may not always be related to
respirable crystalline silica exposure, the test results are
nonetheless useful for detecting lung function abnormalities that can
worsen with further exposure to respirable crystalline silica,
providing a baseline of lung function status against which to assess
any subsequent changes, and assessing the health of employees who wear
respirators. The requirement for lung function testing is also
consistent with other OSHA standards, such as asbestos (29 CFR
1910.1001) and cadmium (29 CFR 1910.1027). Thus, OSHA decided to retain
the proposed requirement for a pulmonary function test in the rule.
    OSHA proposed that spirometry be administered by a spirometry
technician with current certification from a NIOSH-approved spirometry
course. NIOSH recommended changing ``current certification'' to ``a
current certificate'' to clarify that NIOSH does not certify individual
technicians (Document ID 2177, Attachment B, p. 43). OSHA agrees with
NIOSH that the change provides clarity, without modifying the original
meaning of the provision, and thus made the change to the proposed
provision.
    Some stakeholders questioned whether a certificate from a NIOSH-
approved course should be required. For

example, Dow Chemical recommended that OSHA follow the asbestos
standard and allow for spirometry testing to be conducted by a person
who has completed ``a training course in spirometry sponsored by an
appropriate academic or professional institution'' (29 CFR
1910.1001(l)(1)(ii)(B)) (Document ID 2270, pp. 11-12). However, other
stakeholders, including NIOSH and commenters from the medical community
and labor unions, agreed that the standard should require a current
certificate from a NIOSH-approved course (Document ID 2157, p. 6; 2177,
Attachment B, pp. 38-39, 43; 3541, p. 10; 3577, Tr. 777; 4223, pp. 129-
130). Dr. Robert Cohen stated:

. . . spirometry performed by certified NIOSH technicians would be
very important. We don't want garbage spirometry that we see out in
the industry all the time. We want real, not what I call cosmetic or
ceremonial spirometry (Document ID 3577, Tr. 777).

    Dr. James Cone noted an example in which a NIOSH Health Hazard
Evaluation at a foundry found that the company had recorded abnormal
pulmonary function test results for 43 employees; however, spirometry
testing later conducted by NIOSH found that only 9 of those same
employees had abnormal pulmonary function results. Dr. Cone thought
that the difference in findings most likely resulted from differences
in equipment and test procedures used to motivate and elicit
cooperation of employees during testing (Document ID 2157, pp. 4-5). He
concluded:

    The difference does suggest that proper equipment, certification
and training of pulmonary technicians, and standardized reading of
pulmonary function tests are important to maintain uniformity and
comparability of such tests (Document ID 2157, p. 5).

    Some commenters, including Collegium Ramazzini, suggested other
ways that the rule for respirable crystalline silica could improve
quality of spirometry results. It recommended that the rule specify
spirometry conducted according to ATS/European Respiratory Society
(ERS) or similar guidelines, that spirometers meet ATS/ERS
recommendations, and that the third National Health and Nutrition
Examination Survey (NHANES III) reference values be used for
interpretation of results (Document ID 3541, pp. 8-10). Collegium
Ramazzini emphasized that quality spirometry results depend on
standardized equipment, test performance, and interpretation of
results, including criteria, such as acceptability and reproducibility
of results (Document ID 3541, p. 8). Labor unions, such as LHSFNA and
BCTD, also supported more stringent spirometry requirements (Document
ID 3589, Tr. 4205; 4223, pp. 129-130). ACOEM, NIOSH, and BCTD
recommended that reference values or other spirometry guidelines be
added to the appendix on medical surveillance (Document ID 2080, p. 9;
2177, Attachment B, pp. 45-46; 4223, pp. 128-129).
    After considering the record to determine what the rule must
include to improve spirometry quality, OSHA concludes that requiring
technicians to have a current certificate from a NIOSH-approved
spirometry course is essential for maintaining and improving spirometry
quality. The purpose of requiring spirometry technicians to have a
current certificate from a NIOSH-approved spirometry course is to
improve their proficiency in generating quality results that are
interpreted in a standardized way. OSHA included the certification
requirement in the proposed rule because spirometry must be conducted
according to strict standards for quality control and results must be
consistently interpreted. The NIOSH-approved spirometry training is
based upon procedures and interpretation standards developed by the
ATS/ERS and addresses factors, such as instrument calibration, testing
performance, data quality, and interpretation of results (Document ID
3625, pp. 2-3).
    NIOSH approves a spirometry training course if it meets the minimum
OSHA/NIOSH criteria for performance of spirometry testing in the cotton
textile industry. Since these course criteria are based on
recommendations from ATS/ERS, they are applicable to spirometry testing
in all industries. The curriculum of NIOSH-approved courses encompasses
ATS/ERS recommendations on instrument accuracy (e.g., calibration
checks); test performance (e.g., coaching, recognizing improperly
performed maneuvers), and data quality with emphasis on repeatability
and interpretation of results. Students taking the course use actual
equipment, while supervised, and are evaluated on their spirometry
testing skills (Document ID 3625, pp. 2-3). NIOSH periodically audits
spirometry course sponsors who provide the courses (see http://www.cdc.gov/niosh/topics/spirometry/sponsor-renewal-dates.html).
Therefore, based on the evidence in the record for this rulemaking,
OSHA concludes that completing a NIOSH-certified course will make
spirometry technicians knowledgeable about various issues that
commenters raised regarding spirometry quality, and has determined that
the best way to ensure that spirometry technicians receive the level of
quality training approved by NIOSH is to require a certificate from a
NIOSH-approved course.
    In considering the alternative suggestions, OSHA concludes that
requiring a current certificate from a NIOSH-approved course is a
better approach than mandating requirements for equipment, testing
procedures, reference values, and interpretation of results, which
could become outdated. OSHA fully expects that the NIOSH-approved
initial and periodic refresher courses required to maintain a current
certificate under this rule will ensure that technicians keep up-to-
date on the most recent ATS/ERS recommendations on spirometry equipment
and procedures as technology and methods evolve over time.
    In addition, OSHA agrees with commenters that the NHANES III
reference values should be used to interpret spirometry results because
they are the most widely endorsed for use in the U.S. (Document ID
3630, p. 28-29). In cross-sectional testing to evaluate lung function
at a single point in time, spirometry results are compared to reference
values (i.e., spirometry values for individuals of the same gender,
age, height, and ethnicity as the employee being tested). Although
agreeing with commenters on the value of spirometry testing and use of
the NHANES III data set for cross-sectional testing, OSHA disagrees
with commenters that procedures for conducting spirometry and NHANES
III reference values should be included as part of an appendix. As
stated above, OSHA's approach to improving spirometry quality is to
require technicians to have a current certificate from a NIOSH-approved
course. Describing procedures in an appendix is not necessary because
spirometry guidance documents, including a comprehensive guidance
document from OSHA, are widely available. The OSHA spirometry guidance
is available from the OSHA Web site and lists the NHANES III values in
an appendix. OSHA encourages individuals who conduct or interpret
spirometry to review the OSHA guidance on spirometry, which is based on
recommendations by ATS/ERS, ACOEM, and NIOSH (Document ID 3630; 3624;
3629; 3631; 3633; 3634).
    OSHA received one comment regarding the practicality of requiring a
current certificate from a NIOSH-approved course. Dow Chemical claimed
that availability of NIOSH-approved courses may be limited

outside of metropolitan areas (Document ID 2270, p. 11). However,
NIOSH's Web site indicates that course sponsors are located throughout
the U.S. and that some sponsors will travel to a requested site to
teach a course (Document ID 3625, p. 3). Moreover, Dow Chemical also
reported that it and another local company had teamed up to bring in an
instructor to teach a NIOSH-approved course in their geographical area
(Document ID 2270, p. 11). OSHA expects that this is a cost-effective
means of providing NIOSH-approved training in places where none
currently exists and can be replicated by other spirometry providers
that provide services to companies covered by this rule. Maintaining a
certificate from a NIOSH-approved course currently requires initial
training and then refresher training every five years (Document ID
3625, p. 1). Because courses appear to be widely available throughout
the U.S. and the required training is infrequent, OSHA concludes that
the requirement for a technician to maintain a certificate from a
NIOSH-approved course will not impose substantial burdens on providers
of spirometry testing.
    The fifth item required as part of the initial medical examination
is a test for latent tuberculosis infection (paragraph (i)(2)(v) of the
standard for general industry and maritime, paragraph (h)(2)(v) of the
standard for construction). This provision is unchanged from the
proposed rule. ``Latent'' refers to a stage of infection that does not
result in symptoms or possible transmission of the disease to others.
OSHA proposed the inclusion of a test for latent tuberculosis infection
because exposure to respirable crystalline silica increases the risk of
a latent tuberculosis infection becoming active (i.e., the infected
person shows signs and symptoms and is contagious), even in employees
who do not have silicosis (see Section VI, Final Quantitative Risk
Assessment and Significance of Risk) (Document ID 0360; 0465; 0992,
p.1461-1462). This places not only the employee, but also his or her
coworkers, at increased risk of acquiring this potentially fatal
disease.
    OSHA sought comment on its preliminary determination that all
employees receiving an initial medical examination should be tested for
latent tuberculosis infection. A number of stakeholders, including Dr.
James Cone, ATS, NIOSH, APHA, NISA, NSSGA, ASSE, BCTD, and ACOEM agreed
with OSHA's preliminary conclusion that testing for latent tuberculosis
infection should be part of the initial examination (e.g., Document ID
2157, p. 6; 2175, p. 6; 2177, Attachment B, pp. 38-39; 2178, Attachment
1, p. 5; 2195, p. 41; 2327, Attachment 1, p. 23; 2339, p. 9; 2371,
Attachment 1, p. 43). However, other stakeholders, such as Newmont
Mining, Nevada Mining Association, and EEI, recommended that testing
for latent tuberculosis infection be limited to employees who have
silicosis (e.g., Document ID 1963, p. 2; 2107, p. 3; 2357, p. 34). EEI
specifically opposed testing for latent tuberculosis infection in the
absence of radiological evidence of silicosis, arguing that there are
no good methods for quantifying the benefits of that testing.
    After reviewing the comments on this issue, OSHA affirms its
conclusion that testing for latent tuberculosis infections is a
necessary and important part of the initial examination. As noted
above, evidence demonstrates that exposure to respirable crystalline
silica increases the risk for developing active pulmonary tuberculosis
infection in individuals with latent tuberculosis infection,
independent of the presence of silicosis (Document ID 0360; 0465; 0992,
pp. 1461-1462). Active tuberculosis cases are prevented by identifying
and treating those with latent tuberculosis infections. Therefore, OSHA
concludes it is appropriate to test for latent tuberculosis infection
in all employees who will be exposed to respirable crystalline silica
and are eligible for medical surveillance, for their protection and to
prevent transmission of an active, potentially fatal infection to their
coworkers. Any concerns about a lack of good methods for calculating
benefits associated with latent tuberculosis infection testing do not
negate the scientific evidence demonstrating that exposure to
respirable crystalline silica increases the risk of a latent infection
becoming active.
    Newmont Mining, Nevada Mining Association, and Fann Contracting did
not support testing for latent tuberculosis infection because employees
with the infection may not have contracted it in an occupational
setting (Document ID 1963, p. 2; 2107, p. 3; 2116, Attachment 1, p.
38). While that may be true, testing for latent tuberculosis infection
provides another example and support for two of the main objectives of
medical surveillance: (1) To identify conditions that might make
employees more sensitive to respirable crystalline silica exposure; and
(2) to allow for intervention methods to prevent development of serious
disease. Employees with latent tuberculosis infections are at greater
risk of developing active disease with exposure to respirable
crystalline silica, and informing them that they have a latent
infection allows for intervention in the form of treatment to eliminate
the infection. Treating latent tuberculosis disease before it becomes
active and can be transmitted to coworkers (and others) is in the best
interest of both the employer and the affected employee.
    Dr. James Cone and APHA have stated that a positive boosted or
initial test for tuberculosis infection warrants medical referral for
further evaluation (Document ID 2157, p. 6; 2178, Attachment 1, p. 5).
Ameren commented that a positive tuberculosis test warrants medical
removal (Document ID 2315, p. 9). OSHA agrees that employees who test
positive for active tuberculosis should be referred to their local
public health departments as required by state public health law
(Document ID 2177, Attachment B, p. 50). Those employees will need
treatment and, if necessary, to be quarantined until they are no longer
contagious. That is the appropriate action for employees with active
tuberculosis to prevent infection of coworkers and others, according to
procedures established by state public health laws. In the case of
latent tuberculosis, the PLHCP may refer the employee to the local
public health department, where the employee may get recommendations or
prescriptions for treatment. Removal is not necessary for latent
tuberculosis infections because employees with latent tuberculosis
infections are not contagious. More information about testing for
latent tuberculosis infections is included in Appendix B.
    The sixth and final item required as part of the initial medical
examination is any other test deemed appropriate by the PLHCP
(paragraph (i)(2)(vi) of the standard for general industry and
maritime, paragraph (h)(2)(vi) of the standard for construction). This
provision, which is unchanged from the proposed rule, gives the
examining PLHCP the flexibility to determine additional tests deemed to
be appropriate. While the tests conducted under this section are for
screening purposes, diagnostic tests may be necessary to address a
specific medical complaint or finding related to respirable crystalline
silica exposure (Document ID 1511, p. 61). For example, the PLHCP may
decide that additional tests are needed to address abnormal findings in
a pulmonary function test. OSHA considers the PLHCP to be in the best
position to decide if any additional medical tests are necessary for
each individual examined. Under this provision, if a PLHCP decides
another

test related to respirable crystalline silica exposure is medically
indicated, the employer must make it available. EEI commented that OSHA
should clarify that additional tests must be related to occupational
exposure to respirable crystalline silica (Document ID 2357, p. 35).
OSHA agrees and intends the phrase ``deemed appropriate'' to mean that
additional tests requested by the PLHCP must be both related to
respirable crystalline silica exposure and medically necessary, based
on the findings of the medical examination.
    Finally, some stakeholders suggested additional tests to be
included as part of medical examinations. OSHA did not propose a
requirement for the initial examination to include a CT scan to screen
for lung cancer, but a number of commenters thought the rule should
contain such a requirement. UAW requested that OSHA consider LDCT
scanning for lung cancer, with guidance from NIOSH and other medical
experts (Document ID 2282, Attachment 3, pp. 19-20). Charles Gordon
asked Dr. David Weissman if OSHA should consider CT scans for lung
cancer screening of silica-exposed employees, as has been recently
recommended by the U.S. Preventive Service Task Force (USPSTF) for
persons at high risk of lung cancer. Dr. Weissman responded:

    Well, the recommendation that you're referring to related to
very heavy cigarette smokers, people who are age 55 to 80, had a
history of smoking I believe at least 30 pack-years and had smoked
as recently as 15 years ago. That group has a very, very high risk
of lung cancer, and as of this time, there are no recommendations
that parallel that for occupational carcinogens (Document ID 3579,
Tr. 159-160, Attachment 2, p. 2).

    Collegium Ramazzini and USW asked OSHA to consider various
scenarios for LDCT lung cancer screening of employees exposed to
respirable crystalline silica; the different scenarios considered age
(as a proxy for latency), smoking history, and other risk factors, such
as non-malignant respiratory disease (Document ID 4196, pp. 5-6; 4214,
pp. 10-12). Both groups recommended screening in non-smokers, and
Collegium Ramazzini also recommended screening in employees less than
50 years of age; both groups cited National Comprehensive Cancer
Network (NCCN) guidelines as a basis for one or more recommendations,
and Collegium Ramazzini also cited the American Association for
Thoracic Surgery (AATS) guidelines. The Communication Workers of
America (CWA) requested LDCT scans every three years for silica-exposed
employees over 50 years of age (Document ID 2240, p. 3). Consistent
with one scenario presented by USW, AFL-CIO requested that OSHA require
LDCT scans if recommended by the PLHCP or specialist, and AFL-CIO also
requested that OSHA include a provision (for employees exposed to
respirable crystalline silica) to allow for regular LDCT scans if
recommended by an authoritative group (Document ID 4204, p. 82). Dr.
Rosemary Sokas and Dr. James Melius, occupational physician/
epidemiologist for LHSFNA, requested that OSHA reserve the right to
allow for adoption of LDCT scans (Document ID 3577, Tr. 793; 3589, Tr.
4205-4206). Dr. Sokas went on to say that OSHA should start convening
agencies and organizations to look at levels of risk that warrant LDCT
(Document ID 3577, Tr. 793).
    In addition to the issues that Dr. Weissman testified about
regarding the USPSTF recommendations, OSHA notes that the USPSTF
recommendations are based on modeling studies to determine optimum ages
and frequency for screening and the scenarios in which benefits of LDCT
screening (e.g., increased survival) would outweigh harms (e.g., cancer
risk from radiation exposure). The screening scenario recommended by
USPSTF (55- to 80-year-olds with a 30-pack-year smoking history who
have not quit more than 15 years ago) is estimated to result in a 14
percent decrease in lung cancer deaths, with a less than 1 percent risk
for radiation-related lung cancer (Document ID 3965, p. 337). USPSTF
stresses that LDCT screening should be limited to high-risk persons
because persons at lower risk are expected to experience fewer benefits
and more harm; they cautioned that starting LDCT screening before age
50 might result in increased rates of radiation-related lung cancer
deaths (Document ID 3965, p. 336). USPSTF also warns about the high
rate of false positive findings with LDCT, which often lead to more
radiation exposure through additional imaging tests and can result in
invasive procedures, which have their own risks, to rule out cancer. It
cautions that lower rates of lung cancer mortality from LDCT screening
are most likely to be found at institutions demonstrating accurate
diagnoses, appropriate follow-up procedures for abnormal findings, and
clear standards for performing invasive procedures (Document ID 3965,
pp. 333, 336).
    Both NCCN and AATS guidelines recommend screening scenarios that
are similar to the USPSTF guideline (e.g., 55 or more years of age and
at least a 30-pack-year history) (Document ID as cited in 3965, p. 338;
3976, p. 33). NCCN and AATS guidelines also recommend screening for 50-
year-olds or older, who have a 20-pack-year or more smoking history and
an additional risk factor. AATS specifies that the additional risk
factor should result in a cumulative lung cancer risk of at least 5
percent in the next 5 years, and they identify additional risk factors,
such as COPD, with an FEV1 of 70 percent or less of
predicted value, and environmental or occupational exposures, including
silica (Document ID 3976, pp. 33, 35-37). Neither the NCCN nor AATS
guideline recommend screening for individuals younger than 50 years of
age or nonsmokers, and neither NCCN nor AATS indicates that its
guidelines are based on risk-benefit analyses.
    OSHA agrees that employees exposed to respirable crystalline silica
are at increased risk of developing lung cancer, as addressed in
Section V, Health Effects. However, OSHA has two major concerns that
preclude the Agency from requiring LDCT screening for lung cancer under
the respirable crystalline silica rule. The first concern is that
availability of LDCT is likely to be limited. Few institutions that
offer LDCT have the specialization to effectively conduct screening for