using macroeconomic models of the United States (and other
countries). Details of Inforum's macroeconomic model are presented
later in this section.
    \83\ The estimated cost at the time was approximately $650
million in 2009 dollars using a 3 percent discount rate.
    \84\ A ``job-year'' is the term of art used to reflect the fact
that an additional person is employed for a year, not that a new job
has necessarily been permanently created.
---------------------------------------------------------------------------

b. Estimates by Commenters on Employment Effects of the Silica Proposal
    Three commenters on the silica proposal--the National Federation of
Independent Business (NFIB) with the NFIB Research Foundation; the
American Chemistry Council (ACC) with Stuart Sessions of Environomics,
Inc.; and the Construction Industry Safety Coalition (CISC) with
Environomics, Inc.--provided or reported estimates of the employment
effects of the proposed silica rule. These commenter estimates are
summarized below.
    The NFIB Research Foundation performed a study (Document ID 2210,
Attachment 2) to estimate the employment and other macroeconomic
effects of OSHA's proposed rule, using the Agency's own estimates of
the annualized compliance costs of the proposed rule for affected
employers of approximately $637 million in 2009 dollars. The study
modeled (a) anticipated employer costs due to the proposed rule, (b)
changes to private sector demand, and (c) changes to state and local
government spending associated with the proposed rule, and then
forecast their effects using NFIB's Business Size Impact Module (BSIM)
to run a simulation. The BSIM is a dynamic, multi-region model based on
the Regional Economic Models, Inc. (REMI) structural economic
forecasting and policy analysis model, which integrates input-output,
computable general equilibrium, econometric, and economic geography
methodologies. Costs were estimated by five size classes of firms. It
was noted that the annualized compliance costs of the proposed rule:

    . . . also represent new demand for private sector goods and
services for firms who assist businesses affected by the new PEL in

complying with the proposed rule. In the BSIM, this new demand for
goods and services provided by the private sector acts as a
countervailing force to any negative impact on employers the new
annualized compliance costs may have (Document ID 2210, Attachment
2, p. 8).

    The summary findings of the NFIB Research Foundation study included
an overall loss of 27,000 jobs and lost output of over $72 billion in
the long run, with at least half the loss expected to occur in the
small business sector.
    The American Chemistry Council (ACC) (Document ID 4209-A1) reported
on Mr. Sessions's post-hearing brief (Document ID 4231), which provided
estimates of the economic and employment impacts of the general
industry costs to comply with the proposed silica rule and, in
addition, criticized Inforum's estimates of the employment effects of
the proposed silica rule (Inforum, 2011, Document ID 1701).
    Mr. Sessions estimated economic impacts based on the URS
Corporation estimates of $6.131 billion as the cost of the proposed
silica rule on 19 general industry sectors (Document ID 4209-1, pp.
102-103). (Note that the analysis does not include the construction
sector and is more than 50 times higher than OSHA's general industry
cost estimate in the proposal). The economic impacts were estimated in
two analytical steps: (1) estimate the impact of the proposed
regulation's compliance costs on the value of output of the affected
industries; and (2) estimate how the expected changes in output will
reverberate throughout the economy, using IMPLAN--a well-known input-
output model of the U.S. economy.
    The first step was achieved by estimating the amount of cost pass-
through of the compliance costs, using a supply elasticity of 1.0, and
then estimating the demand response to this price increase assuming a
demand elasticity of -1.5. This results in a decline in industry
revenue equal to about 20 percent of annualized compliance costs,
which--given URS's estimates of compliance costs--is equal to $1.23
billion per year. Again using the IMPLAN model, the corresponding
estimated employment effect is 18,000 lost jobs annually (5,400 direct
effect; 5,000 indirect effect; and 7,500 induced effect) and a loss in
economic output/GDP of more than $1.6 billion per year.
    Additionally, Mr. Sessions reviewed Inforum's analysis of the
employment impacts of the proposed rule. He asserted that OSHA had
supplied Inforum with year-by-year compliance costs that were only 53
percent of the annualized costs that OSHA had estimated in the PEA so
that Inforum's projections of employment effects would be seriously
underestimated:

    OSHA estimates the cost of the Proposed Standard to be $658
million per year in 2009 dollars on an annualized basis, excluding
the hydraulic fracturing industry. Assuming a 7%/year discount rate,
this annual cost, continuing forever as OSHA estimates it will, is
equivalent to a present value cost of $9.4 billion dollars in the
initial year of compliance. For comparison with this figure, I
calculate (also assuming a 7% discount rate) that the present value
in the first year for the ten-year schedule of compliance costs
shown in Inforum's Table 1 is only $5.0 billion [italics added]
(Document ID 4231).

    In reviewing the above procedures, OSHA concludes that Mr. Sessions
has misinterpreted his own calculations. The annualized value of an
infinite series of costs (i.e., continuing forever) discounted at 7
percent is equal to 0.07 (the annualization factor) x the present value
(PV). Hence, the annualized cost of Mr. Session's present value of $9.4
billion should equal $658 million. Now, OSHA provided a stream of costs
for 10 years, not forever. The annualization factor for annualized
costs incurred over ten years using a 7 percent discount rate is equal
to 0.1424. Therefore, the PV of OSHA's costs given to Inforum should be
$658 million/0.1424, or about $4.6 billion. Mr. Sessions only confused
issues by using first-year costs (which is irrelevant to his exercise)
rather than annualized costs. So, there is nothing in Mr. Sessions's
calculations that would suggest that OSHA had provided Inforum with
seriously incomplete costs. However, just to make sure, OSHA and ERG
also reviewed the year-by-year proposal cost data given to Inforum (for
Inforum, 2011, Document ID 1701) and found nothing amiss.
    The Construction Industry Safety Coalition, submitted a late
comment on the silica proposal (CISC, 2015), which contains estimates
prepared by Environomics, Inc. (Environomics, 2015) of the employment
impacts of the proposed silica rule on the construction sector
(Document ID 4242). This late comment, including the contained
Environomics study, has been excluded from OSHA decision-making
consideration, but is presented here for informational purposes only.
    The employment effects estimated by Environomics (2015) reflect
annual costs to construction industries of $4.9 billion, which includes
almost $3.9 billion of direct compliance costs to construction
employers and another $1.05 billion of costs passed through from
general industry (as a result of the silica rule for general industry)
to the construction industry (Document ID 4242). Environomics used the
IMPLAN model to translate the estimated $4.9 billion annual cost of the
silica rule into more than 52,700 lost jobs related to the construction
industry. These job losses would consist of about 20,800 in
construction; 12,180 additional jobs lost in industries that supply
materials, products, and services to the construction industry; and
nearly 20,000 further jobs lost when those who lose their jobs in
construction and supplier industries no longer have earnings to spend
(i.e., ``induced'' jobs). Furthermore, Environomics argued that
``(t)hese job figures are expressed on a full-time equivalent basis.
Given the number of part-time and seasonal jobs in construction, the
number of actual workers and actual jobs affected will be much more
than 52,700'' (Environomics, 2015, Document ID 4242, p. 2).
c. Inforum Analysis of Employment Effects of the Final Silica Rule
    In December 2015, OSHA directed Inforum to run its macroeconomic
model to estimate the industry and aggregate employment impacts on the
U.S. economy of the cost of OSHA's final silica rule.\85\ The Agency
believes that the specific model of the U.S. economy that Inforum
uses--called the LIFT (Long-term Interindustry Forecasting Tool)
model--is particularly suitable for this work because it combines the
industry detail of a pure input-output model (which shows, in matrix
form, how the output of each industry serves as inputs in other
industries) with macroeconomic modeling of demand, investment, and
other macroeconomic parameters.\86\ The Inforum model can thus both
trace changes in particular industries through their effect on other
industries and also

examine the effects of these changes on aggregate demand, imports,
exports, and investment, and in turn determine net changes to Gross
Domestic Product (GDP), employment, prices, etc.
---------------------------------------------------------------------------

    \85\ The estimated cost of the final rule that OSHA provided
Inforum was about $962 in annualized terms in December 2015. The
final cost presented in the FEA is about $1,030 million in
annualized terms, or about 7 percent ($68 million) higher than the
costs used by Inforum to estimate the employment effects of the
final rule. OSHA believes that if the most recent cost estimates had
been used, they would have had a minor effect on Inforum's estimate
of the employment impact of the final rule.
    \86\ The LIFT model combines a dynamic input-output (I-O) core
for 110 productive sectors with a full macroeconomic model with more
than 1,200 macroeconomic variables that are consistent with the
National Income and Product Accounts (NIPA) and other published
data. LIFT employs a ``bottom-up'' regression approach to
macroeconomic modeling (so that aggregate investment, employment,
and exports, for example, are the sum of investment and employment
by industry and exports by commodity). Unlike some simpler
forecasting models, price effects are embedded in the model and the
results are time-dependent (that is, they are not static or steady-
state, but present year-by-year estimates of impacts consistent with
economic conditions at the time).
---------------------------------------------------------------------------

    Using industry-by-industry compliance cost estimates provided by
OSHA,\87\ Inforum employed the LIFT model of the U.S. economy to
compute the industry-level and macroeconomic impacts expected to follow
implementation of the silica standard. The general methodology was to
embed the compliance costs into the industry price functions of the
LIFT model, solve the equations of the model with the additional costs
included in the calculations, and then compare the simulation to a
baseline scenario which did not include the additional costs.
Enforcement of the rule was assumed to start in 2017 in construction
and in 2018 in general industry and maritime (with enforcement of
engineering control requirements for hydraulic fracturing activities
beginning in 2021). The timing of the compliance costs reflected the
phased-in enforcement of the rule, and the LIFT model results were
calculated over a ten-year horizon, that is, through 2026.
---------------------------------------------------------------------------

    \87\ OSHA contractor ERG provided silica-rule compliance cost
data for 13 segments of the construction sector plus construction
activity by state and local governments, and for 102 industrial
sectors. The costs were specified in 2012 dollars and covered a 10
year horizon, beginning with the implementation of the rule. The
data covered eight cost types and were classified as intermediate,
capital, and direct labor costs. In order to integrate the
compliance costs within the LIFT model framework, Inforum
established a mapping between the OSHA NAICS-based industries and
the LIFT production sectors. See Inforum (2016) for a discussion of
these and other transformations of OSHA's cost estimates to conform
to the specifications of the LIFT model.
---------------------------------------------------------------------------

    The most significant Inforum result is that the final silica rule
cumulatively generates an additional 9,500 job-years over the period
2017-2026, or an additional 950 job-years annually, on average, over
the period (Inforum, 2016). It should be noted, however, that these
results vary significantly from year to year. For example, in 2017, the
first year in which the silica final rule would be in effect and when
most capital costs for control equipment would be incurred, an
additional 21,100 job-years would be generated as a result of the
silica rule. Then, through 2026, the change in job-years relative to
the baseline ranges from a high of 19,600 (in 2019) to a low of -17,300
(in 2020).\88\ Inforum emphasized that all of these estimated job-year
impacts of the silica rule, both positive and negative, should be
viewed as negligible--relative to total U.S. employment of between 157
and 168 million workers during the time period under consideration and
not statistically different from an estimate of 0 job-years (that is,
that the silica rule would have no job impact).
---------------------------------------------------------------------------

    \88\ The fluctuations in employment from year to year as a
result of the proposed rule reflect how the Inforum model works. The
model has large short-term multipliers (from the initial increase in
compliance expenditures) but long-term stabilizers to return to an
equilibrium output and employment level. Hence, the short-term
multipliers may cause output and employment to overshoot in one year
and adjust in the other direction in the next year or two as the
model (and the real-world economy) equilibrates.
---------------------------------------------------------------------------

    The employment impacts of the silica rule would also vary
significantly from industry to industry and from sector to sector. For
example, for the period 2017-2026, the construction industry would, on
average, gain 4,260 job-years annually while the rest of the U.S.
economy would, on average, lose 3,310 job-years annually. Again,
relative to total employment in the construction sector of about 10
million workers and employment in the rest of the U.S. economy of about
150 million workers over the 10-year period, these employment impacts
should be considered negligible. For a fuller discussion of OSHA's
estimate of the employment and other macroeconomic impacts of the
silica rule, see Inforum (2016).
    One obvious question is why the employment impacts of the silica
rule would be positive in construction and negative elsewhere. There
seem to be two major reasons. One is that, as reflected in the Inforum
model, there is little foreign competition in U.S. construction and the
price elasticity of demand in construction is extremely low relative to
demand for products in most other industries. Hence, output and
employment would be expected to decline minimally in response to any
price increase if employers in construction pass on the costs of the
silica rule. Second, and probably more important, in OSHA's view,
compliance with many of the provisions in the silica rule is relatively
labor-intensive, often requiring the application of additional labor in
the regulated firms themselves. Examples would include time spent for
training, medical surveillance, and activities to meet the PEL (such as
setting up and using control equipment and performing housekeeping
tasks). The increased labor required to produce a unit of output in
regulated firms would tend to increase employment in those industries
(holding output constant). This is particularly true in construction,
where compliance with the PEL would be much more labor-intensive--both
because engineering controls in construction are typically mobile and
require more worker activity and because housekeeping and other worker
actions are expected to play a larger role in achieving compliance with
the PEL. By comparison, engineering control equipment in general
industry/maritime is usually in a fixed location (eliminating the need
for workers to move the equipment) and worker actions would play a
smaller role in achieving compliance with the PEL.
    Finally, OSHA turns to a critique of the commenters' analysis of
employment effects of the proposed silica rule relative to Inforum's
analysis of employment effects of the final silica rule. This critique
reflects comments provided in the Inforum report (Inforum, 2016).
    The NFIB Research Foundation Analysis: Although the NFIB Research
Foundation study (Document ID 2210, Attachment 2) reported that careful
attention was given to the analysis of costs and their attribution by
firm size, it doesn't offer much information on how the BSIM model
works or how the results were obtained. ``From what is generally known
about the REMI model upon which it is based, the general mechanism is
probably the sequence of (1) increased costs leading to (2) increased
output price leading to (3) reduced demand and therefore jobs''
(Inforum, 2016, p. 8). The study does acknowledge that the costs also
represent new private sector demand for firms that assist affected
employers in complying with the new PEL, but the purported positive
impacts of this private sector demand are not visible in the study.
Presumably the reported impacts are net effects that combine the
negative effects from the increased prices and reduced demand of the
affected sectors with the stimulus from spending on the supplying
sectors; however, that is not clear, and the stimulus is not
quantified. In Inforum's analysis (Inforum, 2016), these effects are
explicitly considered, both for intermediate goods and services as well
as investment.
    Another important difference from Inforum's analysis is that the
NFIB study did not attempt to quantify the additional jobs created in
the affected industries. In Inforum's LIFT model, these were captured
as changes in labor productivity. For several industries, especially
construction, although the industry does experience increased costs, it
must also hire more workers to comply with the silica rule. The
additional jobs required in the affected industries are not discussed
or apparently modeled in the NFIB study. In summary, it seems that the

counteracting influences due to intermediate and investment related
purchases from other industries, and the job-creating expenditures in
the affected industries were not, in fact, captured in the study.
    The CISC and ACC Studies: These two studies are being critiqued
together because they both rely on costs many times higher than OSHA's
estimates and because they both made projections using the IMPLAN
model.
    What accounts for the difference between LIFT simulations and the
CISC and ACC estimates? There are several factors at play:
    Probably most importantly, CISC's estimate starts with annual
compliance costs for the construction industry that are nearly 7 times
larger than OSHA's estimates for the construction industry (only) ($4.1
billion vs. an average of over $600 million, both in 2012 dollars).
Meanwhile, the ACC study estimates costs for general industry that are
more than 16 times larger than OSHA's estimates for the final rule
($6.1 billion in 2009 dollars versus $359 million in 2012 dollars.
Moreover, the CISC and ACC studies assumes that the same annualized
cost estimates are imposed each year, whereas the OSHA cost estimates
vary over the 10 year time period, with peak costs occurring in the
first year.
    Neither the CISC nor the ACC application of the IMPLAN model
accounted for the increase in demand for capital equipment and
intermediate goods and services needed to comply with the proposed
silica rule. Thus, the employment and income boosting impacts of these
expenditures are not captured in their analysis. In contrast, Inforum's
methodology uses an explicit price function where annual compliance
costs by industry change commodity prices in proportion to their share
of total annual gross costs. In turn, price changes affect production
and employment through a dynamic general equilibrium framework. Demand
and supply price elasticities in the LIFT model are composites of
several sets of empirically estimated functions for final demand,
exports, imports, and price mark-ups. Furthermore, the parameters of
these functions vary by type of product according to the econometric
estimation.
    At OSHA's request, Inforum made a separate run using the LIFT model
in the absence of the final silica rule for the construction industry
but with the final silica rule for general industry and maritime. The
purpose of this run was to calculate the indirect effects (only) of the
final silica rule for general industry and maritime on prices and
employment in the construction industry (Inforum, 2016). This LIFT
simulation estimated that the final silica rule for general industry
and maritime indirectly increased prices in the construction industry
by an average of .005 percent. The direction, if not the magnitude of
this effect, is consistent with the CISC/Environomics results
(Environomics, 2015, Document ID 4242). This led to a modest decline in
construction output and construction jobs. As shown in Table 9 of the
Inforum report (Inforum, 2016), the decline in jobs varied from +290 to
-940 a year over the period 2017 to 2026, with a cumulative job impact
of -4.8 thousand jobs over the 10-year period. Again, it should be
emphasized that this separate run was made in the absence of the final
silica rule for the construction industry.\89\
---------------------------------------------------------------------------

    \89\ As shown in Table 6 of the Inforum report, the cumulative
effect of the final rule for general industry, maritime, and
construction is to increase construction employment by 42,600 job
years over the 10-year time period, or about 4,260 jobs a year, on
average. Hence, the cumulative effect of the final rule for
construction alone is to increase construction employment by about
47,400 (42,600 + 4,800) jobs, or about 4,740 jobs a year, to the
extent that the two components are additive.
---------------------------------------------------------------------------

    The IMPLAN model is static and cannot compute employment and output
impacts over time, and it cannot show how the economy evolves to cope
with changes in costs. In order to extrapolate over ten years, the
authors simply multiply the first year effects by 10. The results are
implausible for a dynamic economy as the full static one-year impact is
unlikely to be the average impact over the course of several years. At
least theoretically, the economy contains powerful forces pushing it
towards full employment equilibrium. Therefore, most changes to output
and employment due to cost or demand shocks tend to be neutralized
through time. That is, most impacts, negative or positive, will
approach zero over the long term. Indeed, Inforum's LIFT model produces
dynamic results that vary from year to year, which is consistent with
fluctuations in the state of the economy and with short and long term
expenditure effects. It shows how the employment is reallocated among
industries and how the economy eventually will return to the baseline,
or potential, level of employment.
    While the IMPLAN study places the regulatory analysis within the
context of the overall economy, it does not take full advantage of the
framework. For instance, given data for gross output in the base year
it is possible to compute the industry price effect so that the revenue
shocks can be judged relative to a price elasticity of demand. Instead,
the study employs an unrealistically large construct of a 5 to 1
compliance cost to revenue loss. Finally, the IMPLAN model's inability
to model the long-term properties of the economy severely undermines
the study's conclusion of long term cost to the economy.

G. Benefits and Net Benefits

    In this section, OSHA discusses the benefits and net benefits of
the final silica rule. To set out an approach to estimate the benefits,
the Agency will, in the following sections, estimate the number of
silica-related diseases prevented as a result of the rule, estimate the
timing of the potentially avoided diseases, monetize their economic
value, and discount them. Taking into account the estimated costs of
the final rule, presented in Chapter V of the FEA, OSHA will then
estimate the net benefits and incremental benefits of the rule.
Finally, the Agency will assess the sensitivity of the estimates to
changes in various cost and benefit parameters.
    This section presents OSHA's quantitative estimates of what rule-
induced benefits would be under certain assumptions. OSHA acknowledges
that these estimates are heavily influenced by the underlying
assumptions, and also that the long time frame of this analysis (60
years) is a source of uncertainty. The assumptions underlying these
estimates of deaths and morbidity avoided will be discussed in detail
as they appear in the remainder of this chapter, but the major ones are
as follows:
     The exposure profile and other industrial profile data
presented in Chapter III of the FEA reflect both current conditions and
future conditions (extending over the next sixty years);
     To separate the effects of this new rule from the effects
of compliance with existing standards, it is assumed that any workers
currently exposed above the preceding PEL are exposed to levels of
silica that exactly meet the preceding PEL;
     The rule will result in workers being exposed at the new
PEL but will never reduce exposures below the new PEL;
     Workers have identical exposure tenures (45 years, except
where otherwise noted);
     The effects of baseline respirator use on risk are
ignored; and
     The assumptions inherent in developing the exposure-
response functions discussed in Section VI, presented in Table VI-1 of
this preamble, are reasonable throughout the exposure ranges relevant
to this benefits

analysis. (The reasonableness of these assumptions is discussed in
Section VI.)
    The first two assumptions are also the basis for the cost analysis
in Chapter V of the FEA. The basis for the last assumption is discussed
in greater detail in Section VI of this preamble and will be briefly
reviewed in this section. It bears emphasis, however, that the sources
of data for OSHA's benefits analysis are the same as those used in the
Quantitative Risk Assessment (Section VI of this preamble) and the
technological feasibility analysis in Chapter IV of the FEA.
    While OSHA did not quantify the benefits of the ancillary
provisions, consistent with the statute (29 U.S.C. 655(b)(7), section
6(b)(7)), the Agency finds that these provisions are beneficial and
necessary in order for the standard to be fully and correctly
implemented and for the full benefits of the rule to be realized. On
the whole, OSHA intends the requirements for training on control
measures, housekeeping, and other ancillary provisions of the rule to
apply where those measures are used to limit exposures. Without
effective training on use of engineering controls, for example, it is
unreasonable to expect that such controls will be used properly and
consistently. The ancillary provisions found in the rule are generally
standard and common throughout OSHA regulations.
    The provision requiring exposure assessment in general industry is
integral to determining the engineering controls and work practices
needed to control employee exposure to the new PEL, to evaluate the
effectiveness of the required engineering and work practice controls,
and to determine whether additional controls must be instituted. In
addition, monitoring is necessary to determine which respirator, if
any, must be used by the employee, and it is also necessary for
compliance purposes.
    The requirement for regulated areas in general industry and
maritime serves several important purposes including alerting employees
to the presence of respirable crystalline silica at levels above the
PEL, restricting the number of people potentially exposed to respirable
crystalline silica at levels above the PEL, and ensuring that those who
must be exposed are properly protected. Similarly, the competent person
requirement in the construction standard will protect bystanders by
restricting access to work areas only when necessary, benefiting those
bystanders through reduced exposures.
    Written exposure control plans provide a systematic approach for
ensuring proper function of engineering controls and effective work
practices that can prevent overexposures from occurring. OSHA expects a
written exposure control plan will be instrumental in ensuring that
employers comprehensively and consistently protect their employees.
    The medical surveillance provisions have the potential to protect
workers through the early detection of silica-related illnesses and
will enable employees to take actions in response to information about
their health status gleaned from medical surveillance. Additionally, by
requiring medical surveillance to general industry and maritime workers
exposed at or above the action level, OSHA provides an incentive for
employers to further reduce exposures, where possible, to avoid
incurring the costs of medical surveillance.
1. Estimates of the Number of Avoided Cases of Silica-Related Disease
    For reasons described in detail in this preamble, OSHA has adopted
a PEL of 50 [mu]g/m\3\ in its silica standards covering general
industry, maritime, and construction, along with an alternative method
of compliance (Table 1) in construction. Analogous to the estimates in
the PEA, OSHA has calculated estimates of the benefits associated with
the PEL of 50 [mu]g/m\3\ for respirable crystalline silica, and
corresponding Table 1 in construction, by applying the dose-response
relationships developed in OSHA's quantitative risk assessment (QRA) to
exposures at or below the preceding PELs.
a. Exposure Profiles
    OSHA determined exposure levels at or below the preceding PELs by
first developing an exposure profile of current exposures for
industries with workers exposed to respirable crystalline silica, using
OSHA inspection and site-visit data, and then applying this exposure
profile to the total current worker population. The industry-by-
industry exposure profile is presented in Chapter III of the FEA.
    Because OSHA relied solely on measurement of airborne exposures,
respirator use may result in lower baseline exposures inside the
respirator than would be indicated by the airborne exposures
measurements. The extent to which this affects OSHA's benefits
calculations depends on the extent to which there was baseline
respirator use in the risk assessment studies OSHA relied on and how
these studies accounted for respirator use, if they did so at all. OSHA
reviewed the risk assessment studies it is relying on as well as
earlier studies that described the source of exposure data for each
cohort and how exposures were estimated for cohort members to determine
whether respirator use was accounted for. OSHA found that the
overwhelming majority of studies did not mention either respirator use
or how they accounted for respirator use, even though many took place
in time periods and at exposures levels where some respirator use could
have been expected. Some studies accounted for use of ``dust controls''
but did not state whether these ``dust controls'' included respirator
use. Two studies (Rando et al. 2001, Document ID 0415), whose exposure
estimates for North American industrial sand workers were used by
Hughes et al. (2001, Document ID 1060), and Dosemeci et al. (1993),
whose exposure estimates for Chinese mine and pottery workers were
modified and used by Chen et al. (2001, Document ID 0332; 2005,
Document ID 0985), mention adjusting exposure estimates to account for
respirator use, but did not discuss in detail how these adjustments
were calculated. Most studies OSHA relied on, directly or indirectly,
cover long periods of time, over which respirator use varied. Most
cover some time after OSHA set a general industry PEL of approximately
100 [mu]g/m\3\ and required the use of a respirator if that exposure
level was exceeded. In summary, OSHA does not know the extent of
respirator use in the risk assessment studies relied on for the
benefits analysis, nor how they might differ from current respirator
use. As a result, OSHA is unable to accurately adjust its estimates to
account for baseline respirator use.
    OSHA also is not able to quantify the effectiveness of respirator
use. (OSHA regulations provide for assigned protection factors, but
these are based on ideal conditions rather than real world conditions.)
It is thus difficult to know how to correct for possible respirator
use. As will be discussed below, OSHA estimates benefits relative to a
baseline characterized by compliance with the preceding PEL. The
preceding PEL in construction and maritime is approximately 250 [mu]g/
m\3\. If respirators have a protection factor of five, then they would
be equivalent to the new PEL of 50 [mu]g/m\3\ if fully effective at 250
[mu]g/m\3\. In general industry there is a preceding PEL of
approximately 100 [mu]g/m\3\. If respirators have a protection factor
of two, then they would be equivalent to the new PEL of 50 [mu]g/m\3\,
if fully effective. Beyond this, OSHA does not have the data to
quantify the effects of respirator use because it is well known that in
actual practice in work settings, respirators are not always as
protective

as the assigned protection factors would indicate. For the purpose of
estimating the health benefits of the final rule, exposures above the
relevant preceding PELs were set at the relevant preceding PEL; for
purposes of comparing the effects of the preceding and the new
standards, the analysis thus assumes full compliance with both, without
taking baseline respirator use into account.
    By applying the dose-response relationships from the literature to
estimates of exposures at or below the preceding PELs across
industries, it is possible to estimate the number of cases of the
following diseases expected to occur in the worker population given
exposures at or below the preceding PELs (the ``baseline''):
     fatal cases of lung cancer,
     fatal cases of non-malignant respiratory disease (NMRD)
(including silicosis),
     fatal cases of end-stage renal disease, and
     cases of silicosis morbidity.
    Non-fatal cases of lung cancer, NMRD and end-stage renal disease
were not estimated. In that respect, the estimates of the benefits are
understated. However, OSHA's benefits calculations do not, for example,
factor in any impact on the rule's implementation of the following
aspect of the Agency's enforcement approach: As a general matter, where
compliance with a standard's requirement clearly creates a new hazard,
employers can raise a defense that compliance with the requirement is
not feasible, and OSHA would work with the employer to implement an
alternative means of protection that does not create a serious
hazard.\90\
---------------------------------------------------------------------------

    \90\ In FEA Chapter IV, OSHA responds to commenters who have
stated that safety hazards would increase in the presence of the
rule (due to, for instance, use of wet methods on roofs) by
suggesting technologically feasible alternatives, including using
wet methods or exhaust ventilation on the ground or on platforms or
scaffolds. Other commenters also described how fall protection on
roofs was already being used where wet methods are employed.
---------------------------------------------------------------------------

    In a comment suggesting that some reductions in exposures (and thus
some benefits) were not included in OSHA's analysis, Dr. Ruth
Ruttenberg noted that ``OSHA/ERG did not consider stomach cancer,
autoimmune disease, and other cancer and non-cancer health effects of
silica exposure'' (Document ID 2256, Attachment 4, p. 11). These
potential benefits were not quantified, for the PEA or FEA, because the
Agency does not, at this time, have sufficient exposure-response data
to perform a quantitative risk assessment for these illnesses. The
Health Effects and Significance of Risk section of this preamble
contain a more detailed discussion of these potential silica-related
health effects that were not quantified.
b. OSHA's Method for Using Risk Models and Exposure Profile To Estimate
Cases Avoided as a Result of the Rule
    The core of OSHA's methodology for benefits analysis is to
calculate the number of estimated premature deaths and illness cases
avoided as a result of the new rule. To do this, OSHA estimates the
expected number of mortality and morbidity cases expected to occur
under the assumption that the preceding PEL is being met (i.e., those
workplaces where the preceding PEL is currently exceeded are set equal
to the preceding PEL), and then subtract the expected number of
mortality and morbidity cases estimated to occur with the new rule in
place. OSHA then estimates the numbers of disease cases and deaths that
would result after the new standard goes into effect (i.e., assuming
full compliance in that no worker will be exposed in excess of the new
PEL). For this purpose, OSHA assumes all exposures above the new PEL
are reduced to the new PEL of 50 [mu]g/m\3\. The difference between
these estimates represents the numbers of disease cases and deaths that
the Agency estimates would be avoided as a result of issuing the new
standard. That is, this approach focuses on calculating estimates
derived from eliminating those exposures between the preceding PEL and
the new PEL. As explained later, these estimated mortality and
morbidity cases avoided are then monetized to comprise the benefits (in
dollar terms) of the rule.
    By focusing on exposures between the preceding PEL (even for
workers exposed above the preceding PEL) and the new PEL exclusively,
and ignoring the possibility that workers' exposures are reduced below
the new PEL, OSHA's calculations will have a tendency toward
underestimation. Some exposures may be reduced to below the new PEL of
50 [mu]g/m\3\ as a result of engineering controls that do more than
needed. Also, some exposures below the new PEL of 50 [mu]g/m\3\ may be
reduced further due to ``bystander effects,'' by which those already
exposed below the new PEL but working near other exposed workers would
have their exposures reduced further.
    In order to estimate the number of deaths prevented, OSHA uses a
lifetime risk model, which is a mathematical framework that explicitly
follows workers from the beginning of their work lives until
retirement. Workers are assumed to start work at age 20 and work
continuously until age 65, resulting in a 45-year work life, and then
assumed to live another 15 years post-retirement, or until age 80. This
estimate is useful because the OSH Act requires OSHA to examine
exposures for an entire working life. Shorter job tenures will be
discussed further below.
    Using this model, OSHA calculates the workers' cumulative workplace
exposures to silica, and estimates the probability of their dying each
year from silica-related diseases. The model also establishes the
background probability of the workers' dying from non-silica-related
causes. The increase in the workers' probability of dying due to
cumulative silica exposure in the workplace is added to this background
probability. As will be explained in more detail later, the difference
in these probabilities is used to form the basis for estimating the
number of illnesses and deaths due to silica exposures as they
currently exist and the estimated number of illnesses and deaths that
would be avoided when the standard is fully in effect, assuming full
compliance.
    The background, age-specific survival probabilities are based on
the current (2011) U.S. (male) population, the latest year for which
age-specific all-cause mortality statistics are available.\91\ The

exposure-response functions for different diseases, which relate
cumulative silica exposure and increased probabilities of respective
disease endpoints, are drawn from specific studies discussed in this
preamble, Section VI--Final Quantitative Risk Assessment and
Significance of Risk.\92\ Estimates of the number of cases of silicosis
prevented by the new standard were also based on cumulative risk models
taken from several morbidity studies, but were not used in life table
analyses as was done for mortality (see Section VI of this preamble,
Final Quantitative Risk Assessment and Significance of Risk). The
exposure levels used in the model cover the U.S. exposure profile as
presented in Table III-9 in Chapter III Industry Profile of the FEA.
OSHA's exposure profiles for general industry and maritime and for
construction contain the estimated numbers of employees exposed within
specific bands of exposure levels: below 25 [mu]g/m\3\, 25 to 50 [mu]g/
m\3\, and above 50 [mu]g/m\3\ (in bands of 50 [mu]g/m\3\ to 100 [mu]g/
m\3\, 100 [mu]g/m\3\ to 250 [mu]g/m\3\, and above 250 [mu]g/m\3\,
whenever any of these bands are above the preceding PEL, OSHA lowered
the estimate for the band to the preceding PEL).
---------------------------------------------------------------------------

    \91\ Overall, approximately 3 percent of all construction
workers are women. (BLS, 2014--Labor Force Statistics from the
Current Population Survey, available at http://www.bls.gov/cps/cpsaat11.pdf). There is no comparable breakdown for manufacturing
occupations as a whole but, for selected occupations for which data
are available, women are always fewer than 15 percent of the
relevant manufacturing workforce. OSHA used background mortality
rates for the U.S. male population because the cohorts in the key
studies used in the Agency's quantitative risk assessment were
composed overwhelmingly of male workers. OSHA used the exposure-
response models from these studies in a life table analysis to
estimate excess risk of disease mortality from exposure to
respirable crystalline silica after accounting for competing causes
of death due to background causes. Because, in most key studies, the
exposure-response models were built using data from male workers
only, it is unknown how these models would change for female
workers, or for mixed-gender populations, as it is not clear that
females would react to the silica exposure in the same exact way as
males. There is no such model data available for these cohorts.
Furthermore, OSHA believes that use of all-cause mortality data for
the U.S. population as a whole is not appropriate since the working
populations studied in the cohort studies, as well as the present
population of workers covered by the rule, are overwhelmingly male
and do not reflect the nearly equal proportion of males and females
represented by the all-cause mortality data for the U.S. population
as a whole. If one were to assume that the exposure-response model
for female workers was the same as that for male workers, then the
resulting relative risk (RR, the ratio of the risk of disease
mortality occurring in the exposed to the risk of disease mortality
occurring in the unexposed) for a particular cumulative exposure
would be the same. Because the risk of disease mortality in the
exposed population is calculated by multiplying the RR by the
background risk in the unexposed population, the risk of mortality
in the exposed population would be different between females and
males and would depend upon the background gender-specific disease
risks. Because the background cause-specific (e.g., lung cancer or
NMRD) mortality for females is generally lower than that for males,
the Agency would expect that the predicted risk of mortality to
exposed females may be slightly lower than that for exposed males.
On the other hand, this effect may be offset by female workers'
greater likelihood of surviving to the advanced age groups in which
silica-related diseases most typically appear in severe forms and
become a cause of death. Given the absence of exposure-response
models for female workers, which are required to estimate a proper
RR of disease for females, it is impossible to make any sound
conclusion on how the risk estimates would change for female
workers.
    \92\ Specifically the low estimate for lung cancer uses
estimates from ToxaChemica (2004, Document ID 0469), the high
estimate for lung cancer uses Attfield and Costello (2004, Document
ID 0543), the renal disease estimate uses Steenland, Attfield, and
Mannetje (2002) (Document ID 1089), the morbidity estimate for
silicosis uses Buchanan, Miller, and Soutar (2003, Document ID
0306), and the mortality estimate for silicosis uses Mannetje, et.
al. (2002, Document ID 1089). See Section VI--Final Quantitative
Risk Assessment and Significance of Risk in this preamble for more
discussion.
---------------------------------------------------------------------------

    The results in Table III-9 in the FEA represent average daily
exposures in the risk model for general industry and maritime. In
construction, occupational exposure is commonly intermittent (i.e., not
occurring every workday), necessitating an adjustment to accurately
estimate these workers' cumulative exposure and risk. Workers in the
construction sector perform a multitude of tasks, only some of which
involve silica exposure. OSHA's estimated exposure levels represent the
8-hour time-weighted average of exposure on days when workers perform
tasks involving silica exposures. However, to account for the fact
that, in most affected construction occupations, workers do not do such
tasks every day, the cumulative exposure estimate for these workers
needed to be adjusted. To account for this intermittent exposure, the
risk model uses an adjustment factor which estimates the percentage of
days in which a worker will typically perform tasks that generate
silica exposures. These adjustment factors are generally based on the
proportion of time workers perform silica-generating activities along
with associated work crew sizes.\93\ So, for example, if, on average, a
group of workers is estimated to spend 20 percent of its time
performing tasks involving silica exposure, the model multiplies the
base exposure level--the exposure that the group of workers is
estimated to have based on the exposure profile--by this 20 percent. In
the Agency's model, this adjustment factor is calculated as the total
number of full time equivalent days that affected employees spend on
silica-related tasks divided by total affected employment as shown in
Chapter III of the FEA. For all construction occupations other than
hole drillers using hand-held drills, OSHA calculated an FTE adjustment
factor of 28 percent that was derived from the exposure profile. Hole
drillers using hand-held drills have a large number of employees and an
extremely low adjustment factor as compared to all other occupations.
Because the risk models are nonlinear, averaging such disparate groups
together provides unrepresentative results and therefore, this
occupation has its risk calculated separately. For hole drillers using
hand-held drills, OSHA calculated an adjustment factor of 3.5 percent.
---------------------------------------------------------------------------

    \93\ Detailed methodology and estimates for each occupation are
discussed in the construction engineering control cost section in
Chapter V of the FEA, in the subsection entitled ``Aggregate `Key'
and `Secondary' Labor Costs for Representative Projects.''
---------------------------------------------------------------------------

    In order to calculate the number of expected and avoided cases for
each health outcome, OSHA assumes that all workers whose exposures fall
within a band are exposed the same and assigns the average of all
individual exposure observations within the relevant band (i.e., the
mean exposure) as the single point estimate within each band.\94\ This
point estimate of exposure is then used with the associated risk
estimate for each health outcome, which is multiplied by the estimated
number of workers exposed within the exposure band to calculate the
number of workers who experience that health outcome in the absence of
the new rule. For workers currently exposed above the new PEL, OSHA
assumes that their post-rule exposures will be lowered to the new PEL
of 50 [micro]g/m\3\. This reflects the fact that the Agency is taking
no benefits for reducing exposure above the previous PELs to the
previous PELs. The analysis starts from a baseline of the previous
PELs. A similar calculation is then performed at these new exposure
levels for these currently overexposed workers: The numbers of workers
exposed within each exposure band of the post-rule exposure profile is
then multiplied by the associated risk estimates for each health
outcome to yield estimates of the numbers of disease cases and
fatalities that will occur after the standard is implemented. Finally,
subtracting this post-implementation number of deaths and disease cases
from those estimated under baseline (pre-rule) conditions yields an
estimate of the number of deaths and illness cases averted due to the
standard.
---------------------------------------------------------------------------

    \94\ Individual exposure data are presented within various
sections of Chapter IV, Technological Feasibility, of the FEA. All
individual observations are presented in Technical and Analytical
Support for OSHA's Final Economic Analysis for the Final Respirable
Crystalline Silica Standard: Excel Spreadsheets Supporting the FEA,
available in Docket OSHA-2010-0034 at www.regulations.gov.
---------------------------------------------------------------------------

    As an example, Table VII-23-1 presents the summary calculations for
a risk model that produces one estimate of the number of lung cancer
deaths avoided by the revised standard for workers in general industry
if they were all exposed to silica for 45 years (this uses the
ToxaChemica 2004 risk model of lung cancer deaths avoided).

[GRAPHIC] [TIFF OMITTED] TR25MR16.095

    In Table VII-23-1, the total General Industry population at risk
for excess lung cancer is 291,019. There are 142,071 workers in the
range of silica exposure of below 25 [micro]g/m\3\, 51,377 workers
exposed between 25 and 50 [micro]g/m\3\, etc. The ``Model Exposure
Level-Baseline'' row provides the mean exposure level within each
range, which is the point estimate of exposure for which the associated
lifetime risk estimate is used to estimate the number of lung cancer
deaths that occur among workers exposed within each exposure range. For
example, from the exposure profile, the mean exposure for workers in
General Industry who are exposed below 25 [micro]g/m\3\ is 14 [micro]g/
m\3\, and the risk of lung cancer for all workers in this exposure band
is calculated from this average exposure of 14 [micro]g/m\3\. Though
the exposure profile includes 28,297 workers exposed in the range of
100-250 [micro]g/m\3\ and 28,443 workers exposed above 250 [micro]g/
m\3\, to estimate the number of baseline lung cancer deaths, those
workers' exposure levels are set at

the preceding PEL of 100 [micro]g/m\3\. In this example, estimated
benefits due to the new PEL do not include any benefits to workers for
their exposures being reduced to the preceding PEL; only those benefits
associated with the exposure levels being reduced from the preceding
PEL or lower to the new PEL are included in the estimates. The row
labeled ``Model Exposure Level-50 PEL'' shows the expected exposures
among workers that result after the standard is promulgated. Exposures
of workers exposed below 50 [micro]g/m\3\ are expected to remain
unchanged while the exposures of all workers who are currently exposed
above 50 [micro]g/m\3\ are expected to be reduced to the new PEL of 50
[micro]g/m\3\.\95\
---------------------------------------------------------------------------

    \95\ For the purposes of estimating costs and benefits, OSHA
assumes full compliance with all applicable OSHA standards.
---------------------------------------------------------------------------

    Table VII-23-1 also presents the estimated excess risk of lung
cancer per 1,000 workers for each exposure band and the number of lung
cancer deaths that would occur among workers exposed within each
exposure band for 45 years. For example, among workers exposed within
the lowest exposure band, the lifetime risk model estimates an
increased risk of lung cancer above the background mortality risk of
14.7 deaths per 1,000 workers at a constant exposure to 14 [micro]g/
m\3\ silica for 45 years. Multiplying this risk estimate by the number
of workers at risk in that exposure band (142,071) yields an estimated
2,084 lung cancer deaths. Doing the same across the various baseline
exposure level bands results in an estimated baseline total of 5,021
lung cancer deaths due to exposure to silica for the population of
workers at risk. The table shows similar estimated lung cancer risks
and estimated numbers of deaths in the post-standard scenario. For all
workers whose baseline 45-year exposures are at or above 50 [micro]g/
m\3\, the estimated risk of lung cancer associated with exposure at the
new PEL of 50 [micro]g/m\3\ is 19.0 per 1,000 workers. Multiplying this
risk by the number of workers exposed to silica at levels between 50
and 100 [micro]g/m\3\ (41,596), for example, yields an estimated 776
deaths occurring in this group for the post-standard scenario. Doing
the same for each exposure band for the post-standard scenario and
summing across all exposure bands, the number of estimated excess lung
cancer deaths post-standard is 4,858. The next two rows show the
difference between the baseline and the post-standard scenarios, both
for lung cancer death risks (``differential lung cancer death rate'')
and numbers of deaths (``lung cancer deaths averted''). The final total
number of lung cancer deaths averted is 163. Dividing by the analytic
time horizon of 45 years results in about 4 annual deaths averted.
    The preceding example assumes a constant exposure level each year
for 45 years. Elsewhere in this chapter, OSHA examines what would
happen if the day-to-day exposure remains the same but job tenure is
shorter. In order to have a valid comparison, OSHA compares each
scenario to what is estimated to happen over 45 years. All job tasks,
and hence cumulative exposure, do not change with decreased job tenure;
they are just spread over more workers. Thus, if OSHA were to examine a
job tenure of 25 years, almost twice as many workers would be exposed
for almost half as long as for the 45-year assumption. With a strictly
proportional (linear) risk function the benefits of having half the
exposure for twice the number of workers would exactly offset each
other and final benefits would be the same. Hence the net effect of
such changes is directly related to non-linearities in the various
lifetime risk models.
c. Results for Cases Avoided
    OSHA received a number of comments concerning the Agency's
preliminary risk assessment and discussion of the health effects of
silica in this preamble to the proposed rule. Those comments are
discussed in detail in Sections V (Health Effects) and VI (Final
Quantitative Risk Assessment and Significance of Risk) of this preamble
to the final rule.
    OSHA examined the various lung cancer risk models presented in its
QRA to estimate the benefits of lowering the PEL. As can be inferred
from Table VI-1 of the Final QRA, the ToxaChemica, Inc. (2004, Document
ID 0469) log-linear model estimated the lowest estimate of lung cancer
cases avoided from lowering the PEL to 50 or 100 [mu]g/m\3\, whereas
the Attfield and Costello (2004, Document ID 0543) model estimated the
highest number of lung cancer cases avoided. The remainder of the
studies indicated an intermediate reduction in risk. OSHA used the
ToxaChemica 2004 (log-linear model) and Attfield and Costello studies
to characterize a range of estimated lung cancer reduction,
acknowledging that neither of these estimates captures the full range
of uncertainty associated with the models and data used.
    Table VII-24 shows the range of modeled estimates for the number of
avoided fatal lung cancers for PELs of 50 [mu]g/m\3\ and 100 [mu]g/m\3\
for the scenario in which workers are uniformly exposed to silica for
45 years. At the final PEL of 50 [mu]g/m\3\, the modeling approach
yields estimates of 2,921 to 8,246 lung cancers prevented over the
lifetime of the worker population, with a midpoint estimate of 5,584
fatal lung cancers prevented. This is the equivalent of between 65 and
183 cases avoided annually, with a midpoint estimate of 124 cases
avoided annually, given a 45-year working life of exposure.
    Following Park (2002, Document ID 0405), as discussed in the
Agency's QRA, OSHA's estimation model suggests that the final PEL of 50
[mu]g/m\3\ would, in the scenario in which workers are uniformly
exposed to silica for 45 years, prevent 14,606 fatalities over the
lifetime of the worker population from non-malignant respiratory
diseases arising from silica exposure.\96\ This is equivalent to 325
fatal cases prevented annually. Some of these fatalities would be
classified as silicosis, but most would be classified as other
pneumoconiosis and chronic obstructive pulmonary disease (COPD), which
includes chronic bronchitis and emphysema. That is one reason why we
would expect this estimate to exceed the count based solely on death
certificates (for instance, in 2013, CDC's count based on state-
provided vital records is 111 deaths annually from silicosis in the
United States).
---------------------------------------------------------------------------

    \96\ Park et al. (2002, Document ID 0405) also found that silica
exposure was responsible for a significant number of deaths that had
been attributed to diseases other than silicosis.
---------------------------------------------------------------------------

    Certain commenters argued that the recent CDC count of silicosis
mortality from death certificates is evidence that OSHA's benefits were
overestimated.
    Some commenters, such as the American Chemistry Council and Faten
Sabry, Ph.D., representing the Chamber of Commerce, argued--based on
the numbers of silicosis-related deaths recorded in recent years
reported in mortality surveillance data--that OSHA overestimated the
estimated benefits of the standard (Document ID 2263, p. 57; 3729, p.
1; 2288, Appendix 6; 4209, pp. 3-4). Dr. Sabry stated that the 52
deaths reported by the CDC in 2010 where silicosis was identified as an
underlying cause of death were considerably fewer than the number of
silicosis-related deaths that OSHA claimed would be avoided once the
proposed standard becomes fully implemented. Dr. Sabry concluded,
``[s]o, by OSHA's calculation, reducing the PEL to 50 [micro]g/m\3\
will prevent more silicosis-related deaths than actually occur in the
United States today--which suggests that OSHA's risk assessment is
faulty'' (Document ID 2288, Appendix 6). The

National Utility Contractors Association (NUCA) made the same argument
when it asserted: ``OSHA predicts that this proposed rule will prevent
approximately 600 silica related deaths per year, but the CDC is
recording less than 100 deaths per year'' (Document ID 3729, p. 1). The
National Federation of Independent Business also argued that OSHA
estimated 375 prevented cases of silicosis that would have led to
deaths, but the CDC reported only about 150 deaths per year where
silicosis was the underlying cause or a contributing factor, causing
OSHA to overestimate lives saved due to the standard by about 150
percent (Document 2210, Attachment 1, p. 3).
    OSHA disagrees that the silicosis mortality surveillance data alone
provides evidence that OSHA has overstated the quantitative benefits of
the rule. OSHA derived its benefits estimates from exposure data
presented in the Industry Profile chapter of the FEA and from its
quantitative risk assessment, which is based on epidemiological data
that quantify relationships between exposure and disease risk. OSHA
relied on these estimates to estimate the number of silicosis-related
deaths and illnesses that would occur absent a revised standard and the
number of deaths that would be avoided by promulgation of such a
standard. From this analysis, OSHA estimated that 325 deaths from
silicosis and other non-malignant lung disease and 918 silicosis
morbidity cases are estimated to be avoided annually once the full
effects of the standards are realized. The 52 deaths cited by Dr. Sabry
appears to refer to only the number of deaths with silicosis coded as
the ``underlying'' cause of death on death certificates, and does not
include deaths coded with silicosis as a ``contributing'' cause.
Combined with the deaths where silicosis is coded as a ``contributing''
cause, in this case 49, CDC/NIOSH reported a total of 101 deaths where
silicosis was either an underlying cause of death or a contributing
cause of death.
    OSHA's model does not only count fatalities related to silicosis.
OSHA's estimate of the impact of exposure to respirable crystalline
silica includes deaths from other diseases (lung cancer, non-malignant
respiratory disease such as chronic bronchitis and emphysema, and end-
stage renal disease) that, according to scientific evidence, can be
caused by exposure to respirable crystalline silica (Document ID 1711;
2175, p. 2). OSHA also estimated, based on the Park study discussed
previously, that 325 cases of fatal non-malignant respiratory diseases
associated with exposure to silica, including, but not limited to
silicosis, that would be prevented annually due to the final standard.
Thus, OSHA's estimates of the numbers of deaths prevented that are due
to non-malignant respiratory disease are not comparable to surveillance
statistics that only capture silicosis as a cause of death.
Furthermore, Dr. Sabry's comments are primarily focused on the
hydraulic fracturing industry, which only recently became a major
source of silica exposure, where most of the effects of current
exposures will likely not be seen for a number of years, underlining
why this analysis of past trends is not instructive for epidemiological
estimates.
    In response to NUCA's comparison of OSHA's estimate of 679 deaths
avoided to the estimate of fewer than 100 deaths from the surveillance
data, the Agency again points out that the model accounts for causes of
death other than those resulting from silicosis and therefore reported
to CDC/NIOSH in the surveillance data. Therefore, NUCA's comparison is
faulty because focusing exclusively on silicosis mortality fails to
capture silicosis morbidity, as well as mortality and morbidity
resulting from other diseases related to silica exposure, including
lung cancer, other non-malignant respiratory disease such as chronic
bronchitis and emphysema, and renal disease (see Section VI, Final
Quantitative Risk Assessment and Significance of Risk, Table VI-1).
BILLING CODE 4510-26-P

[GRAPHIC] [TIFF OMITTED] TR25MR16.096

BILLING CODE 4510-26-C

    George Kennedy of the National Utilities Contractor's Association
makes a similar ``apples and oranges'' error in his comment:

    OSHA predicts that this rule will prevent approximately 600
silica-related deaths per year. But how is this possible if the CDC
is reporting less than 100? (Document ID 3583, p. 2240)

    Mr. Kennedy's comment is based on comparing CDC counts of
documented silicosis fatality cases, but this count is not a report on
all silica-related deaths. The Agency's articulated need for the
standard, however, is based on the finding that silica exposure results
in an array of adverse, mutually independent health endpoints. In
contrast, the CDC estimate deals with a small part of the overall
health risk from silica exposure.
    As also discussed in the Agency's QRA, OSHA finds that workers with
higher cumulative exposures to silica are at elevated risk of lung
cancer, end-stage renal disease, and non-malignant respiratory
diseases. Based on the midpoint of the lower high-end estimate
(Attfield and Costello, 2004, Document ID 0543) and a higher low-end
estimate (ToxaChemica log-linear model, Document ID 0469), OSHA's
estimation model estimates that the new PEL of 50 [mu]g/m\3\ would, in
the scenario in which workers are uniformly exposed to silica for 45
years prevent 5,584 cases of lung cancer, or about 124 cases annually
upon reaching ``steady state'' (see later discussion of this concept)
in 60 years. Based on Steenland, Attfield, and Mannetje (2002, Document
ID 1089), OSHA's estimation model estimates that the final PEL would
prevent 8,689 cases of end-stage renal disease, or about 193 cases
annually in steady state. And based on Park (2002, Document ID 0405),
OSHA's estimation model estimates that the new PEL would prevent 14,606
cases of non-malignant respiratory diseases (including silicosis) over
the lifetime of 45 cohorts' worth of worker population, or about 325
cases annually in steady state, of which 2,970 (66 annually) are
attributable to diagnosed cases of silicosis, based on Mannetje (2002,
Document ID 1089).
    Combining the three major fatal health endpoints--lung cancer, non-
malignant respiratory diseases, and end-stage renal disease--OSHA's
modeling approach yields estimates that the new PEL would prevent
between 26,216 and 31,541 premature fatalities over the lifetime of the
current worker population, with a midpoint estimate of 28,879
fatalities prevented. This is the equivalent of between 583 and 701
premature fatalities avoided annually, with a midpoint estimate of 642
premature fatalities avoided annually, given a 45-year working life of
exposure.
    In addition, the final silica rule is estimated to prevent a large
number of cases of silicosis morbidity. Table VII-25 is designed to
compare available estimates of actual silicosis cases to the estimates
generated by OSHA exposure profile and models. The first set of rows
compares present estimates of 2/1 and the second set of rows estimates
of 1/0 cases of silicosis generated by various risk models using OSHA's
exposure profile. Going across, the first columns are for a tenure
length of 45 years, the second set for a tenure length of 13 years.
Then below in the second panel, the final set of rows is based on
Rosenman, et al. (2003, Document ID 1166) estimates of actual silicosis
cases, generated with an alternative modeling approach. To be
consistent with OSHA's jurisdiction, OSHA revised Rosenman's estimate
to remove workers not in OSHA's jurisdiction, such as miners. The lower
panel, based on Rosenman, et al. (Document ID 1166), shows, assuming 45
years of exposure, that between 2,700 and 5,475 new cases of silicosis,
at an ILO x-ray rating of 1/0 or higher, are estimated to occur
annually at current exposure levels as a result of silica exposure at
establishments within OSHA's jurisdiction (i.e., excluding miners).\97\
The various models OSHA used yield estimates of between 836 and 8,011
cases, assuming 45 years of exposure and between 393 and 10,107 cases
assuming 13 years of exposure at an ILO x-ray rating of 1/0 or higher.
OSHA's risk models for morbidity using OSHA's exposure profile are thus
somewhat consistent with epidemiologically based estimates of silicosis
cases though some are a bit over the epidemiological estimates. When a
job tenure of 13 years is assumed, the table shows that for most
models, as compared to the 45 year job tenure analysis, the results are
a lower numbers of cases, while other models yield estimates of cases
within the range estimated by Rosenman for U.S. workers other than
miners (who are outside OSHA's jurisdiction.) There are, however,
exceptions. The estimated number of cases for some models falls below
Rosenman's estimates. On the other hand, two models show an increased
number of cases which are above the range of Rosenman's estimates. This
is a result of very high rates of cases expected to occur in persons
exposed at levels above the preceding PELs. Since OSHA does not
estimate benefits to workers exposed at levels above the preceding
PELs, any estimated increase in cases among such workers will not
affect OSHA's benefits analysis.
---------------------------------------------------------------------------

    \97\ Rosenman indicated that the underlying cases of silicosis
morbidity have changed little over time, testifying that data from
the National Intake Survey indicated that the nationwide number of
hospitalizations where silicosis was one of the discharge diagnoses
has remained constant, with 2,028 hospitalizations reported in 1993
and 2,082 in 2011 (Document ID 3425, p. 2).

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

[GRAPHIC] [TIFF OMITTED] TR25MR16.097

    A number of commenters took issue with the general idea that
silicosis is an occupational health problem for workers whose exposures
to silica did not exceed the preceding PELs. These commenters typically
pointed to the significant decline in the number of silicosis deaths
reported by the CDC in the last few decades.
    OSHA does not find these comments persuasive. As explained in depth
in the Health Effects and Risk Assessment sections of this preamble,
while the Agency welcomes any apparent decline in silicosis cases, the
Agency has substantial evidence that significant risk remains at
preceding PELs. The commenters do not account for the undercounting of
silicosis deaths from death certificates, as demonstrated by Rosenman
(Document ID 1166] and others; nor do they address other health
endpoints beyond fatal silicosis. Although the decline in reported
cases may indicate the Agency's success up to this point in reducing
the incidence of silicosis, it cannot be taken as an absolute measure
of how many silica-related disease cases currently exist in the
population. Most silicosis cases are not fatal--given that the total
cases of silicosis have apparently remained largely constant, fewer
silicosis fatalities may mean that more individuals are living with
silicosis for longer periods while ultimately dying of other
causes.\98\
---------------------------------------------------------------------------

    \98\ As indicated previously, Rosenman found that the underlying
cases of silicosis morbidity have changed little over time,
remaining constant, even while reported fatalities have declined
(Document ID 3425, p. 2).
---------------------------------------------------------------------------

    While OSHA has estimated morbidity from silicosis, it has not
attempted to estimate the number of morbidity cases

from these other health endpoints. Including these other endpoints
would increase estimates of the number of overall cases avoided.
    As summarized in Table VII-25, OSHA expects that, in the scenario
in which workers are uniformly exposed to silica for 45 years, the
silica rule will eliminate the majority of 1/0, 1/1, and 1/2 silicosis
cases. However, the Agency has not included the elimination of these
less severe silicosis cases in its estimates of the monetized benefits
and net benefits of the final rule. Instead, as shown above in Table
VII-24, OSHA focused its morbidity-only benefits and related net
benefits analysis exclusively on the number of silicosis cases reaching
the more severe levels of 2/1 and above (moderate-to-severe silicosis,
using the ILO method for assessing severity). As discussed in the
Agency's QRA, OSHA estimates that the new PEL of 50 [mu]g/m\3\ for the
current worker population would, in the scenario in which workers are
uniformly exposed to silica for 45 years, prevent 41,293 cases of
moderate-to-severe silicosis (2/1 or more) over a working life, or
about 918 cases prevented annually.\99\
---------------------------------------------------------------------------

    \99\ The unfiltered count of morbidity cases is reported only in
Table VII-25. The Agency believes the actual number of morbidity-
only cases prevented by the standard in the scenario in which
workers are uniformly exposed for 45 years is somewhere between 918
and 984 cases annually, using Mannetje (2002) (Document ID 1089) to
estimate the number of prevented silicosis fatalities (66) and
excluding these fatalities from the estimated ``morbidity-only''
cases. While the Agency received no comment on its methodology for
counting morbidity cases, in preparing the FEA OSHA discovered that
the simultaneous accounting for morbidity in Buchanan's study of
coal miners (2003, Document ID 0306) and pre-mortality morbidity in
Park (2002) (Document ID 0405) could result in a potential double-
counting of morbidity valuation (discussed later in this chapter),
as some of the Buchanan's cases diagnosed with 2/0+ silicosis at
retirement could ultimately proceed to death. A precise estimate of
the morbidity-only cases is not possible, as Buchanan also excluded
a number of cases where the workers had already died, possibly from
silicosis, so that Buchanan was, in turn, likely underestimating the
total lifetime morbidity risk from silicosis. By relying on
Mannetje, OSHA avoids any potential double counting of benefits.
---------------------------------------------------------------------------

    As previously discussed, OSHA based its estimates of reductions in
the number of silica-related diseases using estimates that reflect a
working life of constant exposure for workers who are employed in a
respirable crystalline silica-exposed occupation for their entire
working lives, from ages 20 to 65.\100\ In other words, these estimates
reflect an assumption that workers do not enter or exit jobs with
silica exposure mid-career or switch to other exposure groups during
their working lives. While the Agency is legally obligated to examine
the effect of exposures from a 45-year working lifetime of
exposure,\101\ for purely informational purposes, the Agency also
alternatively examined the effect of assuming that workers are exposed
to silica for three other tenure lengths: 25, 13, and 6.6 working years
(see Table VII-26a through Table VII-26c for number of cases and Table
VII-28a through Table VII-28d for monetary benefits for all four tenure
levels).
---------------------------------------------------------------------------

    \100\ In construction, the analysis assumes that while workers
gain additional exposure annually, they are not necessarily exposed
to silica constantly, depending upon the demands of the job.
    \101\ Section 6(b)(5) of the OSH Act states: ``The Secretary, in
promulgating standards dealing with toxic materials or harmful
physical agents under this subsection, shall set the standard which
most adequately assures, to the extent feasible, on the basis of the
best available evidence, that no employee will suffer material
impairment of health or functional capacity even if such employee
has regular exposure to the hazard dealt with by such standard for
the period of his working life.'' Given that OSHA must analyze
significant risk over a working life, the Agency estimated benefits
for the affected population over the same period.
---------------------------------------------------------------------------

    Table VII-26a presents cases for a worker exposed for 25 years.
While each individual worker is estimated to have less cumulative
exposure under the 25-years-of-exposure assumption, in fact 56 percent
(25/45) as much, the effective exposed population over time is
proportionately increased (due to the turnover of workforce for a
constant number of jobs, and hence total exposure), over the same time
period. A comparison of Table VII-26a to Table VII-24, reflecting
exposures over 25 working years versus 45 working years, shows
variations in the number of estimated prevented cases by health
outcome. Estimated prevented cases of fatal end-stage renal disease are
higher in the 25-year model, whereas cases of fatal non-malignant
respiratory disease and silicosis morbidity are lower. In the case of
lung cancer, the effect varies by model, with a decrease in the
Attfield and Costello, 2004 higher estimate (Document ID 0543) and an
increase in the ToxaChemica, 2004 lower estimate (Document ID 0469).
Looking at overall totals, the midpoint estimate of the number of
avoided fatalities under the new PEL of 50 [mu]g/m\3\ is 642 for 45
years, increasing to 772 for 25 years. For total morbidity, there
instead is a decrease: from 918 cases avoided for 45 years down to 443
cases avoided for 25 years, Table VII-26b presents results for 13 years
of exposure. For a 13 year job tenure, the midpoint for the number of
fatalities avoided is 982 while the total number morbidity cases
avoided is 246. Finally, Table VII-26c presents the results for 6.6
years of exposure. In this scenario, the midpoint for the number of
fatalities avoided is 1,382 and the total number of morbidity cases
avoided is 194. Looking across the tenure results shows that midpoint
mortality significantly increases with lower tenure, while total
morbidity has a large decrease with lower tenure.
    A commenter, Joseph Liss, objected to the Agency's approach of
simultaneously increasing the estimated exposed population--not because
it was technically incorrect, but because it makes it harder to see the
difference in risk to a particular exposed population (Document ID
1950, pp. 16-19).

BILLING CODE 4510-26-P

[GRAPHIC] [TIFF OMITTED] TR25MR16.098

[GRAPHIC] [TIFF OMITTED] TR25MR16.099

[GRAPHIC] [TIFF OMITTED] TR25MR16.100

[GRAPHIC] [TIFF OMITTED] TR25MR16.101

BILLING CODE 4510-26-C
    OSHA reported in the PEA that in the construction industry, which
has an unusually high rate of job turnover compared to other
industries, BLS data show that the mean job tenure with one's current
employer is 6.6 years (BLS, 2010a, Document ID 1620), and the median
age of construction workers

in the U.S. is 41.6 years (BLS, 2010b, Document ID 1672). OSHA further
noted that BLS does not have data on occupational tenure within an
industry, but that the Agency would expect that job tenure in the
construction occupations as a whole would be substantially greater than
the job tenure with a worker's current employer. None of the commenters
disagreed. Furthermore, many workers may return to the construction
industry after unemployment or work in another industry. Job tenure
with the current employer, however, is longer in the other industries
affected by the silica rule (BLS, 2010a, Document ID 1620).
    Dr. Ronald Bird, submitting a comment on behalf of the U.S. Chamber
of Commerce--as well as an unaffiliated commenter, Joseph Liss--
suggested that OSHA's estimates of disease cases prevented from 45
years of silica exposure is unrepresentative of the typical tenure of
workers affected by the standard, particularly in construction
(Document ID 2368, p. 18; Document ID 1950, pp. 15-19). Dr. Bird
suggested that workers will routinely change occupations in the course
of their lifetime. From a probabilistic standpoint, he calculated that
workers would, on average, likely work in an occupation for less than
six years. The comments directly from the Chamber of Commerce go
further, to say that ``[n]o such 45-year career silica exposures exist
in today's working world . . .'' (Document ID 2288, p. 11).
    The article (Rytina, 1983, Document ID 2368) that Dr. Bird cited
for his data on occupational turnover provides data that refute the
assumptions of Dr. Bird's model. While Dr. Bird assumes that
occupational turnover is constant without regard to age or length of
occupational experience, the Rytina article states:

    Not surprisingly, occupational mobility rates declined sharply
with age . . . The rate for workers age 35-44 was less than one
fourth as high as that for workers 18 and 19 years of age. * * *
[O]ccupational change among older workers occurs less frequently
because of attachments to a particular occupation or the risks of
losing income, job security, and pension rights, which might
accompany an occupational shift (Rytina, 1983, Document ID 2368, p.
5).

    Furthermore, the Rytina article shows that among workers 45 to 54
years of age, 16.5 percent of workers have been in the same occupation
for 25 years or more, and among workers 55 and older, 32.9 percent have
been in the same occupation for 25 years or more. By comparison, Dr.
Bird's model suggests that, regardless of age, no more than 13 percent
of workers will remain in a given occupation for more than 20 years.
    Two commenters also provided evidence of the average tenures of
their workers that is contrary to Dr. Bird's estimates. The National
Industrial Sand Association (NISA) noted, ``many NISA member company
employees work at their workplaces for all or much of their worklives.
In 2004, a study calculated the mean tenure for NISA member company
employees fitting the definition of the study's cohort to be 19.7
years'' (Document ID 2195, p. 19). Southern Company, an electric
utility, noted that it ``has approximately 8000 employees in job titles
performing activities with potential exposures to silica-containing
materials. The average tenure for these employees is 17 years; 37% of
these employees have over 20 years work experience'' (Document ID 2185,
p. 3).
    Other commenters provided evidence to refute the Chamber of
Commerce claim that that 45-year career silica exposures no longer
exist in today's working world (Document ID 2288, p. 11). During the
public hearing, participants on a panel comprised of members of the
International Union of Bricklayers and Allied Craftworkers (BAC) were
asked if they had colleagues who had worked longer than forty years in
their trade. All six of the participants affirmed that they did
(Document ID 3585, Tr. 3053). Further, several labor groups submitted
evidence of lengthy worker tenure. The BAC noted that:

    A review of our International Pension Fund records documented
116 individuals who have worked for 40 years or more. We consider
this figure to understate the work lives of Fund participants
because many of these individuals had previous work experience in
the construction industry before being represented by BAC. In
additional, we believe this figure understates the number of
participants with work lives of 45 years, because the Fund was
established in 1972 and it was not until roughly a decade later that
even half of BAC affiliates had commenced participation in the Fund
(Document ID 4053, Attachment 1, p. 2).

    Similarly, The United Association of Plumbers, Fitters, Welders,
and HVAC Service Techs, submitted that ``a review of membership records
documented 35,649 active members who have worked 45 years or more while
they have been a member of the union.'' They also concur with the BAC
statement that the number may be understated given previous work
experience (Document ID 4073, Attachment 3, p. 1). And the
International Union of Operating Engineers' Central Pension Fund found
the average operating engineer has over 20 years of service in the
trade with a range up to 49.93 years (Document ID 4025, Attachment 1,
pp. 6-7).
    Dr. Bird also objected to OSHA's approach of using a single
representative exposure to measure lifetime exposure. He states: ``If
exposures are variable over the course of a year, the lifetime exposure
pattern is contrary to OSHA's assumption and the benefits from the
proposed reduction in the PEL would be considerably less'' (Document ID
2368, p. 19). Dr. Bird apparently faults the Agency for not considering
the possibility that future exposures may be lower than those observed
on a given day. However, it is equally plausible that a worker's future
exposures may be higher than on the day they were observed by OSHA. The
single-day exposure data is the best available data in the record for
those workers, and the Agency does not find any persuasive evidence in
this record to suggest an obvious bias to characterizing exposure from
a single day rather over the course of consecutive days.
    Paragraph (i)(2)(v) of the general industry and maritime standard
and paragraph (h)(2)(v) of the construction standard also contain
specific provisions for diagnosing latent tuberculosis (TB) in the
silica-exposed population and thereby reducing the risk of TB being
spread to the population at large. OSHA currently lacks good methods
for quantifying these benefits. Nor has the Agency attempted to assess
benefits directly stemming from enhanced medical surveillance in terms
of reducing the severity of symptoms from the illnesses that do result
from present or future exposure to silica. Dr. Ruth Ruttenberg, an
economist representing the AFL-CIO, noted this as a source of the
underestimation of the benefits in her comments (Document ID 2256,
Attachment 4, pp. 9-12). However, no commenters suggested how to
quantify these effects.
    OSHA's risk estimates are based on application of exposure-response
models derived from several individual epidemiological studies as well
as the pooled cohort studies of Steenland et al. (2001, Document ID
0492) and Mannetje et al. (2002, Document ID 1089). OSHA recognizes
that there is uncertainty around any of the point estimates of risk
derived from any single study. In its preliminary risk assessment
(summarized in Section VI of this preamble), OSHA has made efforts to
characterize some of the more important sources of uncertainty to the
extent that available data permit. This specifically includes
characterizing statistical

uncertainty by reporting the confidence intervals around each of the
risk estimates (presented in the Preliminary Quantitative Risk
Assessment, Document ID 1711); by quantitatively evaluating the impact
of uncertainties in underlying exposure data used in the cohort
studies; and by exploring the use of alternative exposure-response
model forms. OSHA finds that these efforts reflect much, but not
necessarily all, of the uncertainties associated with the approaches
taken by investigators in their respective risk analyses. However, for
reasons explained in Section VI of this preamble, OSHA concludes that
characterizing the risks and benefits as a range of estimates derived
from the full set of available studies, rather than relying on any
single study as the basis for its estimates, better reflects the
uncertainties in the estimates and more fairly captures the range of
risks likely to exist across a wide range of industries and exposure
situations.
    Section VI of this preamble provides a more complete discussion of
the source of uncertainty in the risk assessment functions used in this
benefits analysis. The sources of uncertainty include the degree to
which OSHA's risk estimates reflect the risk of disease among workers
with widely varying exposure patterns. Some workers are exposed to
fairly high concentrations of crystalline silica only intermittently,
while others experience more regular and constant exposure. Risk models
employed in the quantitative assessment are based on a cumulative
exposure metric, which is the product of average daily silica
concentration and duration of worker exposure for a specific task.
Consequently, these models assume the same risk for a given cumulative
exposure regardless of the pattern of exposure, reflecting a worker's
long-term average exposure without regard to intermittencies or other
variances in exposure. That is, the use of the cumulative exposure
metric in these models assumes that there are no significant dose-rate
effects in the relationship between silica exposure and risk.
    Possible dose-rate effects in the silica exposure-response
relationships, particularly for silicosis. OSHA's reliance on a
cumulative exposure metric to assess the risks of respirable
crystalline silica is discussed in Section V of this preamble.
Uncertainty with respect to the form of the statistical models used to
characterize the relationship between exposure level and risk of
adverse health outcomes is discussed in Section VI.
    In its quantitative risk assessment, OSHA used the exposure-
response models from the best available evidence (i.e., the key studies
discussed at length in Section V, Health Effects and Section VI, Final
Quantitative Risk Assessment and Significance of Risk) to estimate
risks for 45 years of exposure to the previous PELs, revised PEL, and
the action level. When examining the risk estimates specifically for
silicosis mortality and morbidity in Table VI, one interesting
observation is the apparent difference in the exposure-response
relationship for these two endpoints. For example, for 45 years of
exposure to the action level (25 [mu]g/m\3\), there would be an
estimated 4 deaths from silicosis and 21 cases of silicosis (with chest
X-ray ILO category of 2/1 or greater) per 1,000 workers; at the
previous PEL (100 [mu]g/m\3\), there would be an estimated 11 deaths
from silicosis and 301 cases of silicosis per 1,000 workers. In other
words, nearly 20 percent of silicosis cases are estimated to be fatal
at the relatively low exposure of 25 [mu]g/m\3\ but only about 4
percent are estimated to be fatal at the relatively high exposure of
100 [mu]g/m\3\.\102\ Moreover, as noted previously, morbidity and
mortality estimates change in opposite directions in response to
varying the assumption about workers' total length of exposure.
Although this issue was not explicitly raised in the rulemaking record,
OSHA notes and addresses it here.
---------------------------------------------------------------------------

    \102\ Even if one subtracts off the Table VI-1 estimates of
other silica-attributable diseases (e.g., lung cancer) from the 100
[mu]g/m\3\ denominator, on the assumption that those diseases cause
mortality before silicosis has a chance to do so, the ratio of fatal
silicosis cases to the remaining silicosis diagnoses is still no
more than 6.6 percent at 100 [mu]g/m\3\, as opposed to the ratio of
nearly 20 percent at 25 [mu]g/m\3\.
---------------------------------------------------------------------------

    OSHA attributes this apparent difference in the exposure-response
relationships for silicosis mortality and morbidity to several factors.
First, the silicosis mortality study (ToxaChemica, 2004, Document ID
0469) defined deaths using death certificate data, in which silicosis
or unspecified pneumoconiosis was recorded as the underlying cause of
death. In contrast, the silicosis morbidity study (Buchanan et al.,
2003, Document ID 0306) defined silicosis cases using data from chest
x-rays showing radiographic opacities. These radiographic signs of
silicosis represent an early endpoint that is very different from
silicosis death as the underlying cause of death. Such disparate
endpoints are alone one reason why OSHA does not believe that the
exposure-response curves should necessarily be proportional.
    In addition, as discussed in Section V.E, Comments and Responses
Concerning Surveillance Data on Silicosis Morbidity and Mortality,
silicosis is well-known to be underreported on death certificates in
that deaths due to silicosis could have been reported as tuberculosis
or chronic obstructive pulmonary disease (Document ID 1089, pp. 724-
725; 1030; 3425, p. 2; 3577, Tr. 855, 867; 4204, p. 17; 2175, p. 3;
3577, Tr. 772). Also, silica-exposed workers are at risk for other
silica-related diseases, including lung cancer and renal disease, as
well as other non-exposure-related causes of death such that many
workers who contract silicosis will not ultimately die from silicosis.
Therefore the reported silicosis deaths at any level are the lowest
possible number of such deaths. Workers with higher cumulative
exposures are also likely to be older, and therefore may have a higher
rate of other conditions that could have been listed on death
certificates. Furthermore, as discussed in Section VI, OSHA's risk
assessment required some degree of extrapolation at high doses (e.g.,
45 years of exposure to 250 and 500 [mu]g/m\3\ respirable crystalline
silica) that result in cumulative exposures not experienced by many of
the cohort members studied. Thus, OSHA attributes the apparent non-
proportionality in the exposure-response curves for silicosis mortality
and morbidity to these factors. It is possible nonetheless, that future
research may shed additional light on this topic.
d. Estimating a Stream of Benefits Over Time
    Risk assessments in the occupational environment are generally
designed to estimate the risk of an occupationally related illness over
the course of an individual worker's lifetime. As previously discussed,
the current occupational exposure profile for a particular substance
for the current cohort of workers can be matched up against the
expected profile after the final standard takes effect, creating a
``steady state'' estimate of benefits. However, in order to annualize
the benefits for the period of time after the silica rule takes effect,
it is necessary to create a timeline of benefits for an entire active
workforce over that period.
    There are various approaches for modeling the workforce. As
explained below, OSHA uses a model that considers the effect of
lowering exposures for the entire working population. At one extreme,
however, one could assume that all of the relevant silica exposures
will occur after the

standard goes into effect and none of the benefits occurs until after
the worker retires, or at least 45 years in the future. In the case of
lung cancer, that period would effectively be 60 years, since the 45
years of exposure must be added to a 15-year latency period during
which it is assumed that lung cancer does not develop.\103\ At the
other extreme, one could assume that the benefits occur immediately, or
at least immediately after a designated lag. Neither extreme reflects
the reality that silica-related diseases that this standard aims to
reduce significantly occur at various times during and after the
working lives of these populations of workers, with the majority of
cases occurring sometime after the typical worker is middle aged.
Indeed, based on the various risk models (as detailed in model life
tables in Appendix A to the QRA), which reflect real-world experience
with development of disease over an extended period of time; it appears
that the actual pattern occurs at some point between these two
extremes.
---------------------------------------------------------------------------

    \103\ This assumption is consistent with the 15-year lag
incorporated in the lung cancer risk models used in OSHA's QRA.
---------------------------------------------------------------------------

    The model OSHA uses, therefore, is one that considers the effect of
lowering exposures for the entire working population. This population-
based approach does not simply follow the pattern of the risk
assessments, which are based in part on life tables, and observe that
typically the risk of the illness grows gradually over the course of a
working life and into retirement. While this would be a good working
model for an individual exposed over a working life, it is not very
descriptive of the exposed population as a whole. In the latter case,
in order to estimate the benefits of the standard over time, OSHA
considers that workers currently being exposed to silica are going to
vary considerably in age. Since the health risks from crystalline
silica exposure depend on a worker's cumulative exposure over a working
lifetime, the overall benefits of the final standard will phase in over
several decades, as the cumulative exposure gradually falls for all age
groups, until those now entering the workforce reach retirement and the
annual stream of silica-related illnesses reaches a new, significantly
lowered ``steady state.'' However, the beneficial effects of the rule
begin in the near term and increase over time until that ``steady
state'' is reached; and, for a given level of cumulative exposure, the
near-term impact of the final rule will be greater for workers who are
now middle-aged or older, compared to younger workers with similar
current levels of cumulative exposure. This conclusion follows from the
structure of the relative risk models used in this analysis and the
fact that the background mortality rates for diseases such as lung
cancer, chronic obstructive pulmonary disease and renal disease
increase with age.
    In order to characterize the magnitude of benefits before the
steady state is reached, OSHA created a linear phase-in model to
reflect the potential timing of benefits. Specifically, OSHA estimated
that, for all non-cancer cases, while the number of cases of silica-
related disease would gradually decline as a result of the final rule,
they would not reach the steady-state level until 45 years had passed.
The reduction in cases in any given year in the future was estimated to
be equal to the steady-state reduction (the number of cases in the
baseline minus the number of cases in the new steady state) times the
ratio of the number of years since the standard was implemented and a
working life of 45 years; in other words, the number of non-malignant
silica-relates cases of disease avoided is assumed to increase in
direct proportion to the number of years the standard is in effect
until year 45, at which point the numbers hold steady. This formulation
also assumes that the number of workers is constant over the entire
time frame. Expressed mathematically:

Nt = (C-S) x (t/45),

where Nt is the number of non-malignant silica-related
diseases avoided in year t; C is the current annual number of non-
malignant silica-related diseases; S is the steady-state annual number
of non-malignant silica-related diseases; and t represents the number
of years after the final standard takes effect, with t<=45.
    In the case of lung cancer, the function representing the decline
in the number of cases as a result of the final rule is similar, but
there would be a 15-year lag before any reduction in cancer cases would
be achieved. Expressed mathematically, for lung cancer:

Lt = (Cm-Sm) x ((t-15)/45),

where 15 <=t <=60 and Lt is the number of lung cancer cases
avoided in year t as a result of the final rule; Cm is the
current annual number of silica-related lung cancers; and Sm
is the steady-state annual number of silica-related lung cancers.
    This model was extended to 60 years for all the health effects
previously discussed in order to incorporate the 15-year lag, in the
case of lung cancer, and a 45-year working life. OSHA also has
estimated the benefits using other job tenures. For this purpose, OSHA
examined scenarios for the same number of years--60 years--but with the
work force restarting exposure whenever the first job tenure cycle was
complete.
    OSHA also has estimated the benefits using other job tenures. For
this purpose, OSHA examined scenarios for the same number of years--60
years--but with the work force restarting exposure whenever the first
job tenure cycle was complete.
    In order to compare costs to benefits, OSHA assumes that economic
conditions remain constant and that annualized costs will continue for
the entire 60-year time horizon used for the benefits analysis (as
discussed in Chapter V of the FEA). OSHA invited comments on this
assumption in the PEA, for both the benefit and cost analysis. OSHA was
particularly interested in what assumptions and time horizon should be
used instead and why. The Agency did not receive any comments on this
point.
2. Monetizing the Benefits
    OSHA also estimates the monetary value of health and longevity
improvements of the type associated with the final silica rule. These
estimates are for informational purposes only because OSHA cannot use
benefit-cost analysis as a basis for determining the PEL for a health
standard. The Agency's methodology for monetizing benefits is based on
both the relevant academic literature and on the approaches OSHA and
other regulatory agencies have taken in the past for similar regulatory
actions.
    In explaining OSHA's methodology for monetizing health and
longevity improvements, OSHA relied on a 45 year occupational tenure.
Later, OSHA discusses monetization under alternative occupational
tenures of 25, 13 and 6.6 years.
a. Placing a Monetary Value on Individual Silica-Related Fatalities
Avoided
    To estimate the monetary value of the reductions in the number of
silica-related fatalities, OSHA relied, as OMB recommends in its
Circular A-4, on estimates developed from the willingness of affected
individuals to pay to avoid a marginal increase in the risk of
fatality. While a willingness-to-pay (WTP) approach clearly has
theoretical merit, it should be noted that an individual's willingness
to pay to reduce the risk of fatality would tend to underestimate the
total willingness to pay, which would include the willingness of
others--particularly the

immediate family--to pay to reduce that individual's risk of
fatality.\104\
---------------------------------------------------------------------------

    \104\ See, for example, Thaler and Rosen (1976), (Document ID
1520, pp. 265-266); Sunstein (2004) (Document ID 1523, p. 433); or
Viscusi, Magat and Forrest (1988), the last of whom write that
benefits from improvement in public health ``consist of two
components, the private valuation consumers attach to their own
health, plus the altruistic valuation other members of society place
on their health.'' That paper uses contingent valuation methods to
suggest that the effect of altruism could significantly alter
willingness-to-pay estimates for some kinds of health improvement.
There are, however, many questions concerning how to measure the
altruistic component and the conditions under which it might matter.
---------------------------------------------------------------------------

    For estimates using the willingness-to-pay concept, OSHA relies on
existing studies of the imputed value of fatalities avoided based on
the theory of compensating wage differentials in the labor market.
These studies rely on certain critical assumptions for their estimates,
particularly that workers understand the risks to which they are
exposed and that workers have legitimate choices between high- and low-
risk jobs. Actual labor markets only imperfectly reflect these
assumptions. A number of academic studies, as summarized in Viscusi and
Aldy (2003, Document ID 1220), have shown a correlation between higher
job risk and higher wages, suggesting that employees demand monetary
compensation in return for a greater risk of injury or fatality. The
estimated trade-off between lower wages and marginal reductions in
fatal occupational risk--that is, workers' willingness to pay for
marginal reductions in such risk--yields an imputed value of an avoided
fatality: the willingness-to-pay amount for a reduction in risk divided
by the reduction in risk.
    OSHA has used this approach in many recent proposed and final rules
(see 69 FR 59305 (Oct. 4, 2004) and 71 FR 10099 (Feb. 28, 2006), the
preambles for the proposed and final hexavalent chromium rule).
Limitations to this approach (see Hintermann, Alberini and Markandya,
(2010, Document ID 0739)), have been examined in a recent WTP analysis,
by Kniesner et al. (2012, Document ID 3819), using panel data to
examine the trade-off between fatal job risks and wages. This article
addressed many of the earlier econometric criticisms by controlling for
measurement error, endogeneity, and heterogeneity. Accordingly, OSHA
views this analysis as buttressing the estimates in Viscusi and Aldy
(2003, Document ID 1220), which the Agency is continuing to rely on for
the FEA.\105\
---------------------------------------------------------------------------

    \105\ For example, if workers are willing to pay $50 each for a
1/100,000 reduction in the probability of dying on the job, then the
imputed value of an avoided fatality would be $50 divided by 1/
100,000, or $5,000,000. Another way to consider this result would be
to assume that 100,000 workers made this trade-off. On average, one
life would be saved at a cost of $5,000,000.
---------------------------------------------------------------------------

    OSHA received several comments on the use of willingness-to-pay
measures and estimates based on compensating wage differentials. For
example, Peter Dorman, Professor of Economics, Evergreen State College,
Eric Frumin of Change to Win, and Dr. Ruth Ruttenberg, representing the
AFL-CIO, in addition to critiquing the academic studies used to develop
the willingness-to-pay measure, cited the absence of effective labor
markets for capturing a wage differential for hazardous work (Document
ID 2260, Attachment 1; 2372, Attachment 1, pp. 4-15; 2256, Attachment
4, p. 9). OSHA acknowledges that there has been an absence of a wage
premium for risk in certain labor markets, and cites this absence in
Chapter II of the FEA as an example of market failure. Nonetheless,
while the Agency agrees that the absence of a wage premium for risk
demonstrates the need for regulatory intervention in the labor market,
it does not, in itself, invalidate the use of the willingness-to-pay
approach for the informational purposes for which OSHA calculates
benefits, so long as there are some reasonably well-functioning parts
of the labor market that can be used to estimate the willingness to pay
for some subset of workers. OSHA finds that there are such sections of
the labor market.
    Several studies indicate that there are enough functional parts of
the labor market to allow for some quantification of the risk,
typically expressed as the value of a statistical life (VSL), a
possible measure of willingness to pay. For example, Viscusi and Aldy
(2003) conducted a meta-analysis of studies in the economics literature
that use a willingness-to-pay methodology to estimate the imputed value
of life-saving programs and found that each fatality avoided was valued
at approximately $7 million in 2000 dollars. For the PEA, the Agency
used the GDP Deflator (U.S. BEA, 2010) to convert this estimate to $8.7
million in 2009 dollars for each fatality avoided. For the FEA, the
base year has been further updated to 2012 using the GDP Deflator (U.S.
BEA, 2013), yielding an estimate of $9.0 million per fatality
avoided.\106\
---------------------------------------------------------------------------

    \106\ An alternative approach to valuing an avoided fatality is
to monetize, for each year that a life is extended, an estimate from
the economics literature of the value of that statistical life-year
(VSLY). See, for instance, Aldy and Viscusi (2007) (Document ID
1522) for discussion of VSLY theory and FDA (2003, Document ID 1618,
pp. 41488-9), for an application of VSLY in rulemaking. OSHA has not
investigated this approach which was not recommended by any
commenter in the record. It acknowledges, however, that such an
approach would have the effect of lowering estimated benefits
because silica-related health outcomes largely affect older workers
and retirees as they approach actuarially expected life
expectancies.
---------------------------------------------------------------------------

    There are a number of factors that could influence the value of a
statistical life (VSL) calculation in different labor markets, but for
the purpose of its analysis OSHA has identified methods for normalizing
the risk between markets. For example, in Kniesner, Viscusi, and Ziliak
(2010, Document ID 0767), the authors addressed the issue of the
heterogeneity of the VSL approach among various labor markets by
developing analytical tools (quantile regressions) for differentiating
by income. For the purpose of quantifying the effects of income growth
over time on the value of a statistical life, OSHA relies on their
data, which generally show that VSL increases with increased worker
income (as banded by quartile). Despite potential weaknesses in the VSL
approach, Executive Order 12866 recommends monetization of regulatory
benefits (including increases in longevity), and the Agency concludes
this constitutes the best available method for this purpose.
b. Placing a Monetary Value on Individual Non-Fatal Silica-Related
Diseases Avoided
    In addition to the benefits that are based on the imputed value of
fatalities avoided, workers also place a value on occupational injuries
or illnesses avoided, which reflect their willingness to pay to avoid
monetary costs (for medical expenses and lost wages) and quality-of-
life losses as a result of occupational illness. Silicosis, lung
cancer, and renal disease can be totally disabling and adversely affect
individuals for years or even decades in non-fatal cases, or before
ultimately proving fatal. Because monetary measures of the willingness
to pay for avoiding these illnesses are rare and difficult to find OSHA
has included a range based on a variety of estimation methods.
    Consistent with Buchanan et al. (2003), OSHA estimated the total
number of moderate to severe silicosis cases prevented by the final
rule, as measured by 2/1 or more severe x-rays (based on the ILO rating
system). However, while radiological evidence of moderate to severe
silicosis is evidence of significant material impairment of health,
placing a precise monetary value on this condition is difficult, in
part because the severity of symptoms may vary significantly among
individuals.

For that reason, in the PEA, as well as in the FEA, the Agency has
employed a broad range of valuation, which should encompass the range
of severity these individuals may encounter. Using the willingness-to-
pay approach, discussed in the context of the imputed value of
fatalities avoided, OSHA has estimated a range in valuations (updated
and reported in 2012 dollars) that runs from approximately $64,000 per
case--which reflects estimates developed by Viscusi and Aldy (2003,
Document ID 1220), based on a series of studies primarily describing
simple accidents--to upwards of $5.2 million per case--which reflects
estimates developed by Magat, Viscusi, and Huber (1996, Document ID
0791) for non-fatal cancer. The latter number is based on an approach
that applies a willingness-to-pay value to avoid serious illness that
is calibrated relative to the value of an avoided fatality. OSHA (2006,
Document ID 0941) previously used this approach in the FEA supporting
its hexavalent chromium final rule, and EPA (2003, Document ID 0657)
used this approach in its Stage 2 Disinfection and Disinfection
Byproducts Rule concerning regulation of primary drinking water. EPA
used the study by Magat, Viscusi & Huber (1996, Document ID 0791) on
the willingness to pay to avoid nonfatal lymphoma and chronic
bronchitis as a basis for valuing a case of nonfatal cancer at 58.3
percent of the value of a fatal cancer. OSHA's estimate of $5.2 million
in 2012 dollars for an avoided case of non-fatal cancer is based on
this 58.3 percent figure.
    There are several benchmarks for valuation of health impairment due
to silica exposure, using a variety of techniques, which provide a
number of mid-range estimates between OSHA's high and low estimates of
$5.2 million and $64,000. For example, EPA (2008) recently estimated a
cost of approximately $460,000, in 2008 dollars, per case of chronic
bronchitis, which OSHA (2009) used as the basis for comparison with
less severe lung impairments from diacetyl exposure. Another approach
is to employ a cost-of-injury model. Combining estimates of
productivity losses (i.e., lost wages, fringe benefits, and household
production), medical costs (including hospitalizations), and loss of
quality-of-life components, Miller (2005), using an enhanced cost-of-
injury model, estimated the average silicosis disease cost the
equivalent of $335,000 in 2012 dollars).\107\
---------------------------------------------------------------------------

    \107\ Miller (2005) estimated the cost of a silicosis case,
using an enhanced direct cost approach--including a quality-
adjusted-life-years component--to be $265,808 in 2002 dollars.
---------------------------------------------------------------------------

    Miller (2005) also estimated the morbidity costs of several
different pneumoconioses other than silicosis and found the other cases
to be even more costly to society than silicosis. While the full costs
of renal disease are less well known, the medical costs alone of
dealing with end-stage renal disease run over $64,000 annually per
patient (Winkelmayer, 2002). This suggests that a more comprehensive
analysis of the direct costs of renal disease, as well as for the
various lung impairments, would produce an estimate well above the
$64,000 estimate of injuries in Viscusi and Aldy (2003). Moreover,
several studies (e.g., Alberini and Krupnick, 2000) have found that the
cost of injury approach tends to significantly underestimate the true
economic cost of an injury or illness, relative to the willingness to
pay approach, which includes quality of life impacts and psychic costs
as well as medical costs and lost income. In this way, looking only at
specific elements of this valuation, such as a workers compensation
payouts (to the extent they can be linked to a specific employer in a
timely manner), would dramatically underestimate the cost of the
illness to society.
    Thus, the various studies presented in Chapter VII of the FEA
suggest that the imputed value of avoided morbidity associated with
silica exposure, both for cases preceding death and for non-fatal
cases, ranges between $64,000 and $5.2 million, depending in part on
the model used to compute the value and in part on the severity and
duration of the case. OSHA considers this wide range of estimates is
descriptive of the value of preventing morbidity associated with
moderate-to-severe silicosis, as well as the morbidity preceding
mortality due to other causes enumerated here--lung cancer, lung
diseases other than cancer, and renal disease. OSHA is therefore
applying these values to monetize cases of avoided silica-related
morbidity.\108\ OSHA has included these estimates of silicosis
morbidity throughout the analysis. For mortality, OSHA has included the
midpoints of $64,000 and $5.2 million ($2.63 million) for all mortality
cases. The high and low estimates in the remainder of this document for
mortality not only reflect different point estimates, but different
levels for the morbidity effect.
---------------------------------------------------------------------------

    \108\ For the purpose of simplifying the estimation of the
monetized benefits of avoided illness and death, OSHA simply added
the monetized benefits of morbidity preceding mortality to the
monetized benefits of mortality at the time of death, and both would
be discounted at that point. In theory, however, the monetized
benefits of morbidity should be recognized (and discounted) at the
onset of morbidity, as this is what a worker's willingness to pay is
presumed to measure--that is, the risk of immediate death or an
immediate period of illness that a worker is willing to pay to
avoid--a practice that would increase the present value of
discounted morbidity benefits. A parallel tendency toward
underestimation occurs with regard to morbidity not preceding
mortality, since it implicitly assumes that the benefits occur at
retirement, as per the Buchanan model, but many, if not most, of the
2/0 or higher silicosis cases will have begun years before (with
those classifications, in turn, preceded by a 1/0 classification).
As a practical matter, however, the Agency lacks sufficient data at
this time to refine the analysis in this way.
---------------------------------------------------------------------------

Public Comment on Valuing Non-Fatal Cases of Silicosis
    OSHA requested public input on the issue of valuing the cost to
society of non-fatal cases of moderate-to-severe silicosis, as well as
the morbidity associated with other related diseases of the lung, and
with renal disease. A number of commenters did not directly provide
quantitative estimates of the cost of silicosis or other silica-related
health effects, but provided qualitative descriptions of the heavy
burden to health, work, and family life incurred by having silicosis.
    For example, Alan White, of the United Steelworkers Local Union
593, who developed silicosis after working in a foundry for 16 years as
a general helper, described the practical implications of developing
silicosis:

    First of all, for me, there was the growing problem of being out
of breath sooner than I used to. That's a difficult situation for a
competitor, especially since I didn't know why. Then, I received a
big surprise during the conversation with the first doctor when I
found out that I have silicosis and that I will lose my job. He and
the other doctors all agreed that the diagnosis is silicosis.
Watching your wife and other loved ones cry as they figure out what
silicosis is was a big hit and then, shortly afterward, there was
the radical pay cut from a transfer out of the foundry to a
department where I knew nothing because I chose my health over money
. . . There are also difficulties outside of work and issues for me
to look forward to in the future. Walking while talking on a cell
phone is very exhaustive, as well as walking up the stairs from my
basement to my second floor apartment. I have increasing difficulty
on my current job. Certain irritants like air fresheners, potpourri
and cleaners make home life increasingly difficult and I was told
that it's downhill from here for both work and home life (Document
ID 3477, p. 2).

    Mr. White also described how the foundry went to considerable
expense to hire people to do the job he previously had done, including
the costs to the foundry for mistakes made by the trainees replacing
him. Such personnel costs to the employer would not be

captured by either the willingness-to-pay approach or cost-of-injury
approach.
    In addition to questioning the underlying willingness to pay
approach, at least one commenter indicated various ways in which the
approach employed by OSHA would tend to underestimate the economic
benefits of the rulemaking. Dr. Ruttenberg argued that the WTP approach
does not include costs to third parties of silica-related illnesses and
injuries, starting with a number of government programs:

    In its Preliminary Economic Analysis, OSHA says that it wants
public input on the issue of valuing the cost to society of non-
fatal cases of moderate-to severe silicosis, as well as the
morbidity associated with other related diseases of the lung, and
with renal disease. (PEA, p. VII-15) This is a key request because
adding such societal costs can double the benefits of preventing
these diseases. In an article by a lawyer and two economists looking
at the social cost of dangerous products, Shapiro, Ruttenberg, and
Leigh argue that a large economic burden is borne by private
insurance, government programs, the business community and the
victims and their families. Those affected by occupational
exposures, such as silica, may become eligible for a range of cash
or in-kind assistance. Such programs may include unemployment
compensation, food stamps, Medicaid, Medicare, State Children's
Health Insurance Program (SCHIP), Temporary Assistance for Needy
Families (TANF), Social Security Disability, and Old Age, Survivors
and Disability Insurance. There are also costs for use of military
hospitals and clinics (Document ID 2256, Attachment 4, pp. 9-10)
(citations omitted).

    Part of the cost of the injury or fatality may be borne in
substantial part by the victim's family:

    There is another group of costs that can easily double, or even
triple, the direct and indirect totals. These are social and
economic impacts that are also caused by an incident. They often
involve third-party payments, or stress on the victim or his/her
family members. The financial pressures on a family can include the
need for a caregiver, need for additional income from children or
spouse to fill the gap between previous earnings and workers
compensation, or psychotherapy for family members to cope with harsh
new realities. When children lose their chance at college and higher
future earnings, the impact can be hundreds of thousands of dollars
(Document ID 2256, Attachment 4).

    Dr. Ruttenberg pointed to an existing Department of Transportation
study, which suggested that only a fraction of the economic cost of
motor vehicle accidents was actually borne by the victim, with the
remainder of the costs split between governmental bodies, insurers, and
other parties (Document ID 2256, Attachment 4, p. 11).\109\
---------------------------------------------------------------------------

    \109\ The Agency acknowledges this is a likely and potentially
substantial source of underestimation of morbidity costs and is
currently investigating ways to capture this currently unquantified
dimension of benefits for potential use in future rulemakings.
---------------------------------------------------------------------------

    The Center for Progressive Reform argued that there is value to
reducing economic inequities created by occupational illnesses related
to silica exposure:

    The proposal's implications for fair treatment of workers also
deserve more attention. The proposed standards would benefit a
population comprising mostly construction workers (more than 85% of
the total affected population). This is an industry that is a
bastion for middle class workers and those striving to attain middle
class status. It is also an industry that employs a significant
number of foreign-born and non-union workers, groups who typically
have limited power to negotiate improved working conditions.
Ensuring that these workers' health is better protected against the
hazards of silica exposure is an important step toward reducing
socioeconomic inequality, given the linkages between individual
health and social mobility. Other federal agencies, including the
National Highway Traffic Safety Administration (NHTSA) and
Department of Justice (DOJ), have gone so far as to argue that
equity and other non-monetizable benefits are sufficient to justify
rules for which the monetized costs far outweigh the monetized
benefits. (As with the OSH Act, the authorizing statutes under which
NHTSA and DOJ were acting do not require cost-benefit analysis, much
less require the agencies to produce rules with monetized benefits
that outweigh monetized costs) (Document ID 2351, p. 7) (citations
omitted).

    The Agency recognizes that, as with third party effects, there are
aspects of economic equity issues related to occupational injury,
illness, and mortality that merit attention for policy making. As noted
previously, however, the OSH Act requires that OSHA policy for toxic
substances be ultimately determined by issues of risk and feasibility,
as opposed to cost-benefit criteria.
    The Agency requested public input on the issue of valuing the cost
to society of non-fatal cases of moderate to severe silicosis, as well
as the morbidity associated with other related diseases of the lung,
and with renal disease. The final benefits analysis summarized below
and discussed in greater detail in the FEA incorporates OSHA's response
to public comment.
c. Adjusting Monetized Benefits To Reflect Rising Future Value
    In the PEA, OSHA suggested, provided estimates, and requested
comment on adjusting future values of illness and mortality prevention
to account for changes in real income over time. Ronald White of the
Center for Effective Government favored integrating this element into
the monetized benefits analysis (Document ID 2341, p. 3).\110\ No
commenters argued against it. For the reasons provided in the PEA and
described below, the Agency is adopting this approach and has used it
to develop its primary benefits estimates.
---------------------------------------------------------------------------

    \110\ The estimates of monetized benefits to reflect changes in
real income over time developed in the PEA contained an error in the
formulas (an inconsistent discount rate was used) that resulted in
underestimated benefits. That error has been corrected in the
estimates presented in the FEA.
---------------------------------------------------------------------------

    OSHA's estimates of the monetized benefits of the final rule are
based on the imputed value of each avoided fatality and each avoided
silica-related disease. As previously discussed, these, in turn, are
derived from a worker's willingness-to-pay to avoid a fatality (with an
imputed value per fatality avoided of $9.0 million in 2012 dollars) and
to avoid a silica-related disease (with an imputed value per disease
avoided of between $64,000 and $5.3 million in 2012 dollars). Two
related factors suggest that these values will tend to increase over
time and help to better identify the amount that a worker would be
willing to pay to avoid a fatality.
    First, economic theory and empirical evidence from the relevant
studies indicate that the value of reducing life-threatening and
health-threatening risks--and correspondingly the willingness of