Risk Analysis, Vol. 35, No. 7, 2015
DOI: 10.1111/risa.12341
Perspective
Will the Occupational Safety and Health Administration’s Proposed Standards for Occupational Exposure to Respirable Crystalline Silica Reduce Workplace Risk? Susan E. Dudley1,∗ and Andrew P. Morriss2
The Occupational Safety and Health Administration (OSHA) is developing regulations to amend existing standards for occupational exposure to respirable crystalline silica by establishing a new permissible exposure limit as well as a series of ancillary provisions for controlling exposure. This article briefly reviews OSHA’s proposed regulatory approach and the statutory authority on which it is based. It then evaluates OSHA’s preliminary determination of significant risk and its analysis of the risk reduction achievable by its proposed controls. It recognizes that OSHA faces multiple challenges in devising a regulatory approach that reduces exposures and health risks and meets its statutory goal. However, the greatest challenge to reducing risks associated with silica exposure is not the lack of incentives (for either employers or employees) but rather lack of information, particularly information on the relative toxicity of different forms of silica. The article finds that OSHA’s proposed rule would contribute little in the way of new information, particularly since it is largely based on information that is at least a decade old—a significant deficiency, given the rapidly changing conditions observed over the last 45 years. The article concludes with recommendations for alternative approaches that would be more likely to generate information needed to improve worker health outcomes. KEY WORDS: Crystalline silica; occupational health; Occupational Safety and Health Administration; workplace risk
1. INTRODUCTION
of ancillary provisions for controlling exposure, providing for respiratory protection and medical surveillance, hazard communication, and recordkeeping. Crystalline silica refers to a group of minerals composed of silicon and oxygen atoms that are arranged in a three-dimensional repeating pattern. Because oxygen and silicon are the two most common elements in the Earth’s crust, crystalline silica is abundant in nature. Not only is crystalline silica ubiquitous, but it is valuable for a wide variety of materials and uses. As a result, workers may be exposed to it in a large variety of industries and occupations.(1) Scientists have long recognized that prolonged exposure to free crystalline silica is associated with silicosis, a progressive, incurable
The Occupational Safety and Health Administration (OSHA) is developing regulations to amend existing standards for occupational exposure to respirable crystalline silica (RCS) by establishing a new permissible exposure limit (PEL) as well as a series
1 The
George Washington University Regulatory Studies Center and Trachtenberg School of Public Policy and Public Administration, Washington, DC 20052, USA. 2 Texas A&M School of Law, Fort Worth, TX, USA. ∗ Address correspondence to Susan E. Dudley Director, the George Washington University Regulatory Studies Center and Distinguished Professor of Practice, Trachtenberg School of Public Policy and Public Administration, 805 21st St, NW, #612, Washington, DC 20052, USA; [email protected].
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1192 disease that involves scarring of the lungs and impaired respiratory function.(2) The U.S. National Toxicology Program has also found associations between exposure to certain forms of crystalline silica and lung cancer, and deemed that “RCS, primarily quartz dust occurring in industrial and occupational settings, is known to be a human carcinogen.”(3) OSHA has struggled for over 40 years to develop regulations to address risks from exposure to RCS,(4) and still faces a number of challenges. First, a successful risk reduction strategy must consider the complex biological, mineralogical, chemical, physical, and other characteristics of silica, as well as avenues of exposure, and a range of individual factors including personal characteristics unrelated to the exposure, such as smoking habits. Second, given the limitations on our understanding of what forms of silica are most hazardous and what factors mediate those hazards, as well as what practices will best reduce risks, OSHA faces the problem of trying to bring about desirable behavior without having a clear idea of what that behavior should look like. Thus, OSHA faces multiple challenges in devising a regulatory approach that will meet its statutory goal of reducing significant risks. However, the greatest challenge to reducing risks associated with silica exposure is not lack of employer or employee incentives, but rather lack of information.(5) Thus, a successful policy for reducing risks from silica must first encourage the generation of better information on the hazards associated with different forms of silica, the risks involved in different exposure pathways, and mechanisms to reduce risks. In an analysis of OSHA’s proposal filed on the public rulemaking docket, we conclude that, if promulgated as proposed, the rule would contribute little in the way of new information and, indeed, may stifle needed generation of knowledge by precluding flexibility for experimentation and learning.(6) Our analysis is summarized in this article. We begin with a brief review of OSHA’s proposed regulatory approach and the statutory authority on which it is based. We then evaluate OSHA’s preliminary determination of significant risk and its analysis of the risk reduction achievable by its proposed controls. We conclude with recommendations for alternative approaches that would be more likely to generate information needed to improve employee outcomes.
Dudley and Morriss 2. SUMMARY OF STATUTORY AUTHORITY AND OSHA PROPOSAL Section 6(b)(5) of the Occupational Safety and Health Act (OSH Act) requires OSHA to promulgate a standard that reduces significant risk to the extent that it is technologically and economically feasible to do so. The Supreme Court has found that, under the statute, “before the Secretary can promulgate any permanent health or safety standard, he must make a threshold finding that the place of employment is unsafe in the sense that significant risks are present and can be eliminated or lessened by a change in practices.”(7) The Court further concluded that OSHA “must support its findings that a certain level of risk exists with substantial evidence,” but “recognize[d] that its determination that a particular level of risk is ‘significant’ will be based largely on policy considerations.”(7) OSHA proposes to find that: (1) occupational exposure to RCS at current PELs constitutes a “significant risk,” (2) the proposed standard will substantially reduce that risk, (3) the proposed standard is technologically and economically feasible, and (4) it is cost effective. It is proposing a new PEL of 50 micrograms per cubic meter of air (µg/m3 ) for RCS (defined as quartz, cristobalite, and tridymite). This represents a significant reduction from the current PELs, which OSHA adopted in 1971 and that are expressed as formulas. The current PEL for quartz in general industry is approximately equivalent to 100 µg/m3 as an eight-hour time-weighted average. The PEL for quartz in construction and shipyards is a formula based on a 1962 consensus standard relying on a nowobsolete particle count sampling method that OSHA reports is approximately equivalent to 250 µg/m3 . The current PELs for cristobalite and tridymite are one-half of the values for quartz in general industry. In addition to the PEL, OSHA proposes to impose requirements for exposure assessment, preferred methods for controlling exposure, respiratory protection, medical surveillance, hazard communication, and record keeping. 3. ANALYSIS In this section, we examine OSHA’s preliminary determination as to whether current exposure levels
Perspective constitute a significant risk, whether the proposed requirements will substantially reduce that risk, and whether those actions are cost effective. We do not address the issue of whether the standards are “feasible” according to the definitions in the OSH Act and subsequent interpretations.
3.1 Do Current Levels Pose a Significant Risk? The level of risk in the absence of regulation represents the baseline from which OSHA estimates risk reduction benefits of its proposed rule. To generate that counterfactual, it is important to look at trends in worker exposure to RCS and observed health outcomes over time. The International Agency for Research on Cancer reports on an analysis of 7,209 personal sample measurements collected during 2,512 OSHA inspections during 1988–2003, which
1193 suggest that geometric mean crystalline silica exposure levels declined in some high-risk construction industries during the period under study, and revealed a significant decline when compared with silica exposure levels found in a previous study by Stewart & Rice (1990). Geometric mean airborne silica exposure levels among workers in various construction industries were significantly lower in 1988–2003 than in 1979–1987.(1)
Statistics maintained by the National Institute of Occupational Safety and Health (NIOSH) indicate that the number of silicosis mortalities declined from 557 in 1968 to 731 in 2007, as illustrated in Fig. 1. Despite these trends, OSHA relies on risk levels reported in 2002 as the baseline to develop its determination of the significance of the risk and its estimates of the risk reduction potential of its proposed regulation.(9) The proposal estimates that the rule would avoid 375 cases of fatal silicosis and other nonmalignant respiratory diseases each year.(10 p. 56339) This seems unrealistic given the dramatic declines over the past decades, the continued decline since
Fig. 1. Silicosis: Number of deaths, crude and age-adjusted death rates, U.S. residents age 15 and over, 1968–2007. Source: NIOSH reference number: 2012F03–01. (Mortality multiple cause-of-death data from National Center for Health Statistics, National Vital Statistics System. Population estimates from U.S. Census Bureau.)
1194 2002,(11) and the NIOSH estimate of 123 mortalities associated with silicosis in 2007.(8) If OSHA had taken account of recent trends in establishing its baseline, rather than assuming that the trend abruptly stopped in 2002, its estimated benefits from the proposed requirements would likely be much lower. A more realistic baseline might also lead to a different conclusion than OSHA has preliminarily reached about whether workers face a “significant risk.” 3.2 Will the Proposal Achieve a Substantial Reduction in Risk? Once OSHA has made the “threshold finding” that crystalline silica is a significant workplace risk,(7) under its statute it must then identify regulatory strategies that will substantially reduce that risk, while also being feasible and cost effective. A reasonable first step in designing such strategies would be to try to understand what contributed to the declines in silicosis over the last several decades, but OSHA does not explore this in its proposal. OSHA’s ability to address the remaining risks is also constrained by limited information on the relative toxicity of different forms of crystalline silica. OSHA defines RCS broadly, though it “acknowledges that differences exist in the relative toxicity of crystalline silica particles present in different work settings due to factors such as the presence of mineral or metal impurities on quartz particle surfaces, whether the particles have been freshly fractured or are aged, and size distribution of particles.”(10 pp. 165–166) Without fully accounting for the variation in silica potency, and without acknowledging the declining trend in silicosis, OSHA estimates that its proposed rule will “prevent 688 fatalities and 1,585 silica-related illnesses annually once it is fully effective,” at an estimated cost of $637 million annually. In discounted present value terms, OSHA estimates “the proposed rule [will] generate net benefits of $4.6 billion annually.”(10 p. 12) The evidence for that assertion is weak, however, and hinges on questionable assumptions not only regarding what risks would be present in the absence of the regulations (the baseline problem noted above), but the potency of different forms of silica, and how effective the regulation will be at reducing exposure and risks. For example, provisions other than the PEL itself represent approximately $223 million (or about
Dudley and Morriss 34%) of the rule’s estimated total annualized cost of $658 million (using a 7% discount rate).(10 p. 23) Yet, all the rule’s estimated benefits derive from reducing exposure to the level of the PEL. OSHA is unable to articulate a causal link between any of the proposed engineering controls (for respirators, medical surveillance, hazard communication, and record keeping) and its projected incremental changes in exposure to harmful forms of silica or in health outcomes. Instead, OSHA justifies the requirements with vague assertions of experience and tradition: OSHA is proposing to require primary reliance on engineering controls and work practices because reliance on these methods is consistent with long-established good industrial hygiene practice, with the Agency’s experience in ensuring that workers have a healthy workplace, and with the Agency’s traditional adherence to a hierarchy of preferred controls.(10 p. 16)
OSHA could likely contribute far more to worker safety by focusing on understanding the causes of the reduction in silicosis mortality over the last several decades, and the variations in toxicity of different types of RCS in different workplace environments, rather than relying on “traditional adherence” as the basis for regulatory measures. It could then share information on effective programs and practices that actually have been linked to reductions in exposure and risk, instead of requiring engineering controls and work practices for which it has little evidence of effectiveness. 3.3 Alternatives OSHA Considered While OSHA proposes to establish a set of engineering and procedural requirements, it also lays out several alternatives to the proposed PEL and ancillary provisions, as required by its governing statute and presidential executive orders. President Clinton’s Executive Order 12866 states that “each agency shall identify and assess alternative forms of regulation and shall, to the extent feasible, specify performance objectives, rather than specifying the behavior or manner of compliance that regulated entities must adopt”(12) (emphasis added). President Obama’s Executive Order 13563 reinforced the earlier Order and also directed agencies to consider “providing economic incentives to encourage the desired behavior, such as . . . providing information upon which choices can be made by the public.”(13) Two of the alternatives OSHA presents in the preamble appear more consistent with the emphasis on performance standards and flexible approaches
Perspective that provide information and incentives to encourage desired behavior, and also encourage experimentation and opportunities for expanding knowledge as to how best to reduce the risks of RCS. Regulatory Alternative #7 would establish a PEL of 50 µg/m3 , but “eliminate all of the ancillary provisions of the proposed rule, including exposure assessment, medical surveillance, training, and regulated areas or access control.” The PEL would serve as a performance standard, as directed by E.O. 12866, but would allow employers to determine the most effective way to meet that standard. OSHA carefully notes that “in order to meet the PEL, employers would still commonly need to do monitoring, train workers on the use of controls, and set up some kind of regulated areas to indicate where respirator use would be required,” and expects that “employers would increasingly follow the many recommendations to provide medical surveillance for employees.” The advantage of such an approach, perhaps accompanied by information sharing guided by OSHA, is that it would provide incentives for experimentation and learning regarding effective practices. Under Regulatory Alternative #9, OSHA would delay the effective date of a rule with the PEL and action levels as proposed (a PEL of 50 µg/m3 and an action level of 25 µg/m3 ), and at the same time issue an interim PEL of 100 µg/m3 and an action level of 50 µg/m3 to be in effect until the final rule takes effect. Given the declining trends in silica exposure and health effects in the absence of regulation, the risk associated with these two alternatives (or perhaps a combination of the two—an interim PEL with a commitment to evaluating progress pursuant to the lookback provisions of E.O. 13563) would appear to be small while the potential gains in knowledge generation could be great. 4. DISCUSSION AND RECOMMENDATIONS OSHA has struggled for over 40 years to develop regulations to address risks from exposure to crystalline silica,(4) and still faces challenges in establishing effective regulations. Exposure to forms of RCS is associated with silicosis mortality and lung cancer, as well as other nonfatal effects. NIOSH researchers note that, despite a declining trend between 1981 and 2004, “about 30 silicosis deaths yearly have been recorded [between 1995 and 2004] among those of working age (15–64).”(11) Current standards are based on obsolete sampling methods and OSHA has been working on the proposed draft regulation
1195 since at least 1998 (when it first appeared on its semiannual agenda of upcoming regulatory actions). OSHA faces multiple challenges in devising a regulatory approach that will meet its statutory goal of reducing significant risk. However, the greatest challenge to reducing risks associated with silica exposure is not lack of incentives (on the part of employers or employees) but rather lack of information, particularly information on variability in potency of different forms and exposure routes. Unfortunately, OSHA’s proposed rule contributes little in the way of new information. Before OSHA can properly fulfill its statutory authority to identify and reduce significant risks, it must first understand what forms of silica lead to these risks. Furthermore, to devise solutions to address remaining risks, OSHA’s analysis should at least recognize the observed declines in silicosis mortality over the last several decades, and work to understand the reasons behind these encouraging trends. OSHA’s proposal does not recognize or attempt to explain the decline in silicosis mortality reported in the literature. Instead, without justification, it assumes these observed trends will abruptly stop unless OSHA issues the proposed regulation. Its statutory mandate requires more “substantial evidence” to support a standard. Not only is this analytical approach certain to overstate the risk reduction benefits attributable to the rule, but it misses opportunities to identify and encourage successful risk reduction practices. OSHA’s engineering controls give a false impression of precision as its analysis assumes that they will lead to workplace exposures below the proposed PEL. These are merely assumptions, however, as OSHA is unable to support causal connections between specific requirements and reduced exposure or improved health outcomes. Perhaps more important, such standards provide no incentive for increasing knowledge about silica hazards in the workplace; indeed, they may even discourage it by focusing attention on compliance with procedural steps rather than on harm reduction. Given the costs and time involved in changing OSHA regulations, the designbased standards are unlikely to encourage investigations by private parties into developing information as to the relative hazard of different forms of silica, or practices likely to reduce risks.(5) To address the information problem that is at the root of continued risks from silica exposure, OSHA should follow the guidance of Executive Orders
1196 12866 and 13563 and focus its rule on performance standards rather than methods of compliance,(12) and devise strategies that provide information, maintain flexibility for experimentation, and encourage the generation of knowledge.(13) ACKNOWLEDGMENTS We thank reviewers for their many helpful comments and suggestions. REFERENCES 1. IARC. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, “Silica Dust, Crystalline, in the Form of Quartz or Cristobalite” Vol. 100C. Washington, DC: IARC, 2012. 2. Graham WBG. Quartz and silicosis. Pp. 191–212 in Banks DE, Parker JE (eds.) Occupational Lung Disease: An International Perspective. London: Chapman and Hall, 1998. 3. National Institute of Health. Toxicology Program, Report on Carcinogens. Bethesda, MD: National Institute of Health, 2011. 4. Dudley SE. Toxic Sand? OSHA’s Challenge in Regulating Crystalline Silica. Washington, DC: George Washington University Regulatory Studies Center, 2013.
Dudley and Morriss 5. Morriss AP, Dudley SE. Defining what to regulate: Silica and the problem of regulatory categorization. Administrative Law Review, 2006; 58:269–357. 6. Dudley SE, Morriss AP. Public Interest Comment on the Occupational Safety and Health Administration’s Proposed Standards for Occupational Exposure to Respirable Crystalline Silica. Washington, DC: George Washington University Regulatory Studies Center, 2013. 7. U.S. Supreme Court. Indus. Union Dep’t, AFL-CIO v. Am. Petroleum Inst. 448 U.S. 607 (1980), s.l.: U.S. Supreme Court, 1980. 8. National Institute for Occupational Safety and Health. Silicosis: Mortality. s.l. Center for Disease Control, 2012. 2012F03– 01. 9. Occupational Safety and Health Administration. Preliminary Economic Analysis and Initial Regulatory Flexibility Analysis. Washington, DC: U.S. Department of Labor, 2013. 10. Occupational Exposure to Respirable Crystalline Silica. Occupational Safety and Health Administration. Washington, DC: Federal Register, 2013, Vol. 78 FR 56273. 11. Bang KM, Attfield MD, Wood JM, Syamlal G. National trends in silicosis mortality in the United States, 1981– 2004. American Journal of Industrial Medicine, 2008; 51:633– 639. 12. Clinton WJ. Executive Order 12866: Regulatory Planning and Review. Washington, DC: Presidential Documents, 1993. 13. Obama BH. Executive Order 13563: Improving Regulation and Regulatory Review. Washington, DC: Presidential Documents, 2011.
DOI: 10.1111/risa.12341
Perspective
Will the Occupational Safety and Health Administration’s Proposed Standards for Occupational Exposure to Respirable Crystalline Silica Reduce Workplace Risk? Susan E. Dudley1,∗ and Andrew P. Morriss2
The Occupational Safety and Health Administration (OSHA) is developing regulations to amend existing standards for occupational exposure to respirable crystalline silica by establishing a new permissible exposure limit as well as a series of ancillary provisions for controlling exposure. This article briefly reviews OSHA’s proposed regulatory approach and the statutory authority on which it is based. It then evaluates OSHA’s preliminary determination of significant risk and its analysis of the risk reduction achievable by its proposed controls. It recognizes that OSHA faces multiple challenges in devising a regulatory approach that reduces exposures and health risks and meets its statutory goal. However, the greatest challenge to reducing risks associated with silica exposure is not the lack of incentives (for either employers or employees) but rather lack of information, particularly information on the relative toxicity of different forms of silica. The article finds that OSHA’s proposed rule would contribute little in the way of new information, particularly since it is largely based on information that is at least a decade old—a significant deficiency, given the rapidly changing conditions observed over the last 45 years. The article concludes with recommendations for alternative approaches that would be more likely to generate information needed to improve worker health outcomes. KEY WORDS: Crystalline silica; occupational health; Occupational Safety and Health Administration; workplace risk
1. INTRODUCTION
of ancillary provisions for controlling exposure, providing for respiratory protection and medical surveillance, hazard communication, and recordkeeping. Crystalline silica refers to a group of minerals composed of silicon and oxygen atoms that are arranged in a three-dimensional repeating pattern. Because oxygen and silicon are the two most common elements in the Earth’s crust, crystalline silica is abundant in nature. Not only is crystalline silica ubiquitous, but it is valuable for a wide variety of materials and uses. As a result, workers may be exposed to it in a large variety of industries and occupations.(1) Scientists have long recognized that prolonged exposure to free crystalline silica is associated with silicosis, a progressive, incurable
The Occupational Safety and Health Administration (OSHA) is developing regulations to amend existing standards for occupational exposure to respirable crystalline silica (RCS) by establishing a new permissible exposure limit (PEL) as well as a series
1 The
George Washington University Regulatory Studies Center and Trachtenberg School of Public Policy and Public Administration, Washington, DC 20052, USA. 2 Texas A&M School of Law, Fort Worth, TX, USA. ∗ Address correspondence to Susan E. Dudley Director, the George Washington University Regulatory Studies Center and Distinguished Professor of Practice, Trachtenberg School of Public Policy and Public Administration, 805 21st St, NW, #612, Washington, DC 20052, USA; [email protected].
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1192 disease that involves scarring of the lungs and impaired respiratory function.(2) The U.S. National Toxicology Program has also found associations between exposure to certain forms of crystalline silica and lung cancer, and deemed that “RCS, primarily quartz dust occurring in industrial and occupational settings, is known to be a human carcinogen.”(3) OSHA has struggled for over 40 years to develop regulations to address risks from exposure to RCS,(4) and still faces a number of challenges. First, a successful risk reduction strategy must consider the complex biological, mineralogical, chemical, physical, and other characteristics of silica, as well as avenues of exposure, and a range of individual factors including personal characteristics unrelated to the exposure, such as smoking habits. Second, given the limitations on our understanding of what forms of silica are most hazardous and what factors mediate those hazards, as well as what practices will best reduce risks, OSHA faces the problem of trying to bring about desirable behavior without having a clear idea of what that behavior should look like. Thus, OSHA faces multiple challenges in devising a regulatory approach that will meet its statutory goal of reducing significant risks. However, the greatest challenge to reducing risks associated with silica exposure is not lack of employer or employee incentives, but rather lack of information.(5) Thus, a successful policy for reducing risks from silica must first encourage the generation of better information on the hazards associated with different forms of silica, the risks involved in different exposure pathways, and mechanisms to reduce risks. In an analysis of OSHA’s proposal filed on the public rulemaking docket, we conclude that, if promulgated as proposed, the rule would contribute little in the way of new information and, indeed, may stifle needed generation of knowledge by precluding flexibility for experimentation and learning.(6) Our analysis is summarized in this article. We begin with a brief review of OSHA’s proposed regulatory approach and the statutory authority on which it is based. We then evaluate OSHA’s preliminary determination of significant risk and its analysis of the risk reduction achievable by its proposed controls. We conclude with recommendations for alternative approaches that would be more likely to generate information needed to improve employee outcomes.
Dudley and Morriss 2. SUMMARY OF STATUTORY AUTHORITY AND OSHA PROPOSAL Section 6(b)(5) of the Occupational Safety and Health Act (OSH Act) requires OSHA to promulgate a standard that reduces significant risk to the extent that it is technologically and economically feasible to do so. The Supreme Court has found that, under the statute, “before the Secretary can promulgate any permanent health or safety standard, he must make a threshold finding that the place of employment is unsafe in the sense that significant risks are present and can be eliminated or lessened by a change in practices.”(7) The Court further concluded that OSHA “must support its findings that a certain level of risk exists with substantial evidence,” but “recognize[d] that its determination that a particular level of risk is ‘significant’ will be based largely on policy considerations.”(7) OSHA proposes to find that: (1) occupational exposure to RCS at current PELs constitutes a “significant risk,” (2) the proposed standard will substantially reduce that risk, (3) the proposed standard is technologically and economically feasible, and (4) it is cost effective. It is proposing a new PEL of 50 micrograms per cubic meter of air (µg/m3 ) for RCS (defined as quartz, cristobalite, and tridymite). This represents a significant reduction from the current PELs, which OSHA adopted in 1971 and that are expressed as formulas. The current PEL for quartz in general industry is approximately equivalent to 100 µg/m3 as an eight-hour time-weighted average. The PEL for quartz in construction and shipyards is a formula based on a 1962 consensus standard relying on a nowobsolete particle count sampling method that OSHA reports is approximately equivalent to 250 µg/m3 . The current PELs for cristobalite and tridymite are one-half of the values for quartz in general industry. In addition to the PEL, OSHA proposes to impose requirements for exposure assessment, preferred methods for controlling exposure, respiratory protection, medical surveillance, hazard communication, and record keeping. 3. ANALYSIS In this section, we examine OSHA’s preliminary determination as to whether current exposure levels
Perspective constitute a significant risk, whether the proposed requirements will substantially reduce that risk, and whether those actions are cost effective. We do not address the issue of whether the standards are “feasible” according to the definitions in the OSH Act and subsequent interpretations.
3.1 Do Current Levels Pose a Significant Risk? The level of risk in the absence of regulation represents the baseline from which OSHA estimates risk reduction benefits of its proposed rule. To generate that counterfactual, it is important to look at trends in worker exposure to RCS and observed health outcomes over time. The International Agency for Research on Cancer reports on an analysis of 7,209 personal sample measurements collected during 2,512 OSHA inspections during 1988–2003, which
1193 suggest that geometric mean crystalline silica exposure levels declined in some high-risk construction industries during the period under study, and revealed a significant decline when compared with silica exposure levels found in a previous study by Stewart & Rice (1990). Geometric mean airborne silica exposure levels among workers in various construction industries were significantly lower in 1988–2003 than in 1979–1987.(1)
Statistics maintained by the National Institute of Occupational Safety and Health (NIOSH) indicate that the number of silicosis mortalities declined from 557 in 1968 to 731 in 2007, as illustrated in Fig. 1. Despite these trends, OSHA relies on risk levels reported in 2002 as the baseline to develop its determination of the significance of the risk and its estimates of the risk reduction potential of its proposed regulation.(9) The proposal estimates that the rule would avoid 375 cases of fatal silicosis and other nonmalignant respiratory diseases each year.(10 p. 56339) This seems unrealistic given the dramatic declines over the past decades, the continued decline since
Fig. 1. Silicosis: Number of deaths, crude and age-adjusted death rates, U.S. residents age 15 and over, 1968–2007. Source: NIOSH reference number: 2012F03–01. (Mortality multiple cause-of-death data from National Center for Health Statistics, National Vital Statistics System. Population estimates from U.S. Census Bureau.)
1194 2002,(11) and the NIOSH estimate of 123 mortalities associated with silicosis in 2007.(8) If OSHA had taken account of recent trends in establishing its baseline, rather than assuming that the trend abruptly stopped in 2002, its estimated benefits from the proposed requirements would likely be much lower. A more realistic baseline might also lead to a different conclusion than OSHA has preliminarily reached about whether workers face a “significant risk.” 3.2 Will the Proposal Achieve a Substantial Reduction in Risk? Once OSHA has made the “threshold finding” that crystalline silica is a significant workplace risk,(7) under its statute it must then identify regulatory strategies that will substantially reduce that risk, while also being feasible and cost effective. A reasonable first step in designing such strategies would be to try to understand what contributed to the declines in silicosis over the last several decades, but OSHA does not explore this in its proposal. OSHA’s ability to address the remaining risks is also constrained by limited information on the relative toxicity of different forms of crystalline silica. OSHA defines RCS broadly, though it “acknowledges that differences exist in the relative toxicity of crystalline silica particles present in different work settings due to factors such as the presence of mineral or metal impurities on quartz particle surfaces, whether the particles have been freshly fractured or are aged, and size distribution of particles.”(10 pp. 165–166) Without fully accounting for the variation in silica potency, and without acknowledging the declining trend in silicosis, OSHA estimates that its proposed rule will “prevent 688 fatalities and 1,585 silica-related illnesses annually once it is fully effective,” at an estimated cost of $637 million annually. In discounted present value terms, OSHA estimates “the proposed rule [will] generate net benefits of $4.6 billion annually.”(10 p. 12) The evidence for that assertion is weak, however, and hinges on questionable assumptions not only regarding what risks would be present in the absence of the regulations (the baseline problem noted above), but the potency of different forms of silica, and how effective the regulation will be at reducing exposure and risks. For example, provisions other than the PEL itself represent approximately $223 million (or about
Dudley and Morriss 34%) of the rule’s estimated total annualized cost of $658 million (using a 7% discount rate).(10 p. 23) Yet, all the rule’s estimated benefits derive from reducing exposure to the level of the PEL. OSHA is unable to articulate a causal link between any of the proposed engineering controls (for respirators, medical surveillance, hazard communication, and record keeping) and its projected incremental changes in exposure to harmful forms of silica or in health outcomes. Instead, OSHA justifies the requirements with vague assertions of experience and tradition: OSHA is proposing to require primary reliance on engineering controls and work practices because reliance on these methods is consistent with long-established good industrial hygiene practice, with the Agency’s experience in ensuring that workers have a healthy workplace, and with the Agency’s traditional adherence to a hierarchy of preferred controls.(10 p. 16)
OSHA could likely contribute far more to worker safety by focusing on understanding the causes of the reduction in silicosis mortality over the last several decades, and the variations in toxicity of different types of RCS in different workplace environments, rather than relying on “traditional adherence” as the basis for regulatory measures. It could then share information on effective programs and practices that actually have been linked to reductions in exposure and risk, instead of requiring engineering controls and work practices for which it has little evidence of effectiveness. 3.3 Alternatives OSHA Considered While OSHA proposes to establish a set of engineering and procedural requirements, it also lays out several alternatives to the proposed PEL and ancillary provisions, as required by its governing statute and presidential executive orders. President Clinton’s Executive Order 12866 states that “each agency shall identify and assess alternative forms of regulation and shall, to the extent feasible, specify performance objectives, rather than specifying the behavior or manner of compliance that regulated entities must adopt”(12) (emphasis added). President Obama’s Executive Order 13563 reinforced the earlier Order and also directed agencies to consider “providing economic incentives to encourage the desired behavior, such as . . . providing information upon which choices can be made by the public.”(13) Two of the alternatives OSHA presents in the preamble appear more consistent with the emphasis on performance standards and flexible approaches
Perspective that provide information and incentives to encourage desired behavior, and also encourage experimentation and opportunities for expanding knowledge as to how best to reduce the risks of RCS. Regulatory Alternative #7 would establish a PEL of 50 µg/m3 , but “eliminate all of the ancillary provisions of the proposed rule, including exposure assessment, medical surveillance, training, and regulated areas or access control.” The PEL would serve as a performance standard, as directed by E.O. 12866, but would allow employers to determine the most effective way to meet that standard. OSHA carefully notes that “in order to meet the PEL, employers would still commonly need to do monitoring, train workers on the use of controls, and set up some kind of regulated areas to indicate where respirator use would be required,” and expects that “employers would increasingly follow the many recommendations to provide medical surveillance for employees.” The advantage of such an approach, perhaps accompanied by information sharing guided by OSHA, is that it would provide incentives for experimentation and learning regarding effective practices. Under Regulatory Alternative #9, OSHA would delay the effective date of a rule with the PEL and action levels as proposed (a PEL of 50 µg/m3 and an action level of 25 µg/m3 ), and at the same time issue an interim PEL of 100 µg/m3 and an action level of 50 µg/m3 to be in effect until the final rule takes effect. Given the declining trends in silica exposure and health effects in the absence of regulation, the risk associated with these two alternatives (or perhaps a combination of the two—an interim PEL with a commitment to evaluating progress pursuant to the lookback provisions of E.O. 13563) would appear to be small while the potential gains in knowledge generation could be great. 4. DISCUSSION AND RECOMMENDATIONS OSHA has struggled for over 40 years to develop regulations to address risks from exposure to crystalline silica,(4) and still faces challenges in establishing effective regulations. Exposure to forms of RCS is associated with silicosis mortality and lung cancer, as well as other nonfatal effects. NIOSH researchers note that, despite a declining trend between 1981 and 2004, “about 30 silicosis deaths yearly have been recorded [between 1995 and 2004] among those of working age (15–64).”(11) Current standards are based on obsolete sampling methods and OSHA has been working on the proposed draft regulation
1195 since at least 1998 (when it first appeared on its semiannual agenda of upcoming regulatory actions). OSHA faces multiple challenges in devising a regulatory approach that will meet its statutory goal of reducing significant risk. However, the greatest challenge to reducing risks associated with silica exposure is not lack of incentives (on the part of employers or employees) but rather lack of information, particularly information on variability in potency of different forms and exposure routes. Unfortunately, OSHA’s proposed rule contributes little in the way of new information. Before OSHA can properly fulfill its statutory authority to identify and reduce significant risks, it must first understand what forms of silica lead to these risks. Furthermore, to devise solutions to address remaining risks, OSHA’s analysis should at least recognize the observed declines in silicosis mortality over the last several decades, and work to understand the reasons behind these encouraging trends. OSHA’s proposal does not recognize or attempt to explain the decline in silicosis mortality reported in the literature. Instead, without justification, it assumes these observed trends will abruptly stop unless OSHA issues the proposed regulation. Its statutory mandate requires more “substantial evidence” to support a standard. Not only is this analytical approach certain to overstate the risk reduction benefits attributable to the rule, but it misses opportunities to identify and encourage successful risk reduction practices. OSHA’s engineering controls give a false impression of precision as its analysis assumes that they will lead to workplace exposures below the proposed PEL. These are merely assumptions, however, as OSHA is unable to support causal connections between specific requirements and reduced exposure or improved health outcomes. Perhaps more important, such standards provide no incentive for increasing knowledge about silica hazards in the workplace; indeed, they may even discourage it by focusing attention on compliance with procedural steps rather than on harm reduction. Given the costs and time involved in changing OSHA regulations, the designbased standards are unlikely to encourage investigations by private parties into developing information as to the relative hazard of different forms of silica, or practices likely to reduce risks.(5) To address the information problem that is at the root of continued risks from silica exposure, OSHA should follow the guidance of Executive Orders
1196 12866 and 13563 and focus its rule on performance standards rather than methods of compliance,(12) and devise strategies that provide information, maintain flexibility for experimentation, and encourage the generation of knowledge.(13) ACKNOWLEDGMENTS We thank reviewers for their many helpful comments and suggestions. REFERENCES 1. IARC. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, “Silica Dust, Crystalline, in the Form of Quartz or Cristobalite” Vol. 100C. Washington, DC: IARC, 2012. 2. Graham WBG. Quartz and silicosis. Pp. 191–212 in Banks DE, Parker JE (eds.) Occupational Lung Disease: An International Perspective. London: Chapman and Hall, 1998. 3. National Institute of Health. Toxicology Program, Report on Carcinogens. Bethesda, MD: National Institute of Health, 2011. 4. Dudley SE. Toxic Sand? OSHA’s Challenge in Regulating Crystalline Silica. Washington, DC: George Washington University Regulatory Studies Center, 2013.
Dudley and Morriss 5. Morriss AP, Dudley SE. Defining what to regulate: Silica and the problem of regulatory categorization. Administrative Law Review, 2006; 58:269–357. 6. Dudley SE, Morriss AP. Public Interest Comment on the Occupational Safety and Health Administration’s Proposed Standards for Occupational Exposure to Respirable Crystalline Silica. Washington, DC: George Washington University Regulatory Studies Center, 2013. 7. U.S. Supreme Court. Indus. Union Dep’t, AFL-CIO v. Am. Petroleum Inst. 448 U.S. 607 (1980), s.l.: U.S. Supreme Court, 1980. 8. National Institute for Occupational Safety and Health. Silicosis: Mortality. s.l. Center for Disease Control, 2012. 2012F03– 01. 9. Occupational Safety and Health Administration. Preliminary Economic Analysis and Initial Regulatory Flexibility Analysis. Washington, DC: U.S. Department of Labor, 2013. 10. Occupational Exposure to Respirable Crystalline Silica. Occupational Safety and Health Administration. Washington, DC: Federal Register, 2013, Vol. 78 FR 56273. 11. Bang KM, Attfield MD, Wood JM, Syamlal G. National trends in silicosis mortality in the United States, 1981– 2004. American Journal of Industrial Medicine, 2008; 51:633– 639. 12. Clinton WJ. Executive Order 12866: Regulatory Planning and Review. Washington, DC: Presidential Documents, 1993. 13. Obama BH. Executive Order 13563: Improving Regulation and Regulatory Review. Washington, DC: Presidential Documents, 2011.
