FactSheet. Workers Exposure to Respirable Crystalline Silica: Final Rule Overview. More than 2 million workers gain protections from deadly dust

Transcription

1 FactSheet Workers Exposure to Respirable Crystalline Silica: Final Rule Overview More than 2 million workers gain protections from deadly dust Background Workplace illness takes the lives of thousands of workers each year. Those workers and their families rely on the U.S. Department of Labor s Occupational Safety and Health Administration to set and enforce standards that reduce the risk to those workers of contracting illnesses or suffering injuries on the job, so that no worker is forced to sacrifice their life or health for their livelihood. Respirable crystalline silica is particularly hazardous for the nation s workers. Workers who inhale very small crystalline silica particles are at increased risk of developing serious and often deadly silica-related diseases. These tiny particles (known as respirable particles) can penetrate deep into workers lungs and cause silicosis, an incurable and sometimes fatal lung disease. Crystalline silica exposure also puts workers at risk for developing lung cancer, other potentially debilitating respiratory diseases such as chronic obstructive pulmonary disease, and kidney disease. Approximately 2.3 million people in the U.S. are exposed to silica at work. To better protect workers from dangerous crystalline silica, OSHA has finalized two new silica standards: one for general industry and maritime, and the other for construction. These rules are based on extensive review of peer-reviewed scientific evidence, current industry consensus standards, an extensive public outreach effort, and nearly a year of public comment, including several weeks of public hearings. They provide commonsense, affordable and flexible strategies for employers to protect workers in their workplaces from the serious risks posed by silica exposure. OSHA estimates these standards will save the lives of more than 600 workers each year and prevent more than 900 cases of silicosis each year once the full effects of the rule are realized. What is crystalline silica? Crystalline silica is a common mineral that is found in materials that we see every day in roads, buildings, and sidewalks. It is a common component of sand, stone, rock, concrete, brick, block, and mortar. Exposures to crystalline silica dust occur in common workplace operations involving cutting, sawing, drilling, and crushing of concrete, brick, block, rock, and stone products (such as construction tasks), and operations using sand products (such as in glass manufacturing, foundries, sand blasting, and hydraulic fracturing). Why do we need new silica standards? We have known about the dangers of silica for decades. More than 80 years ago, U.S. Secretary of Labor Frances Perkins first brought experts and stakeholders together to determine the best ways to protect workers from silica. OSHA s current permissible exposure limits for silica are more than 40 years old. They are based on research from the 1960s and earlier that do not reflect more recent scientific evidence. Strong evidence shows that the current exposure limits do not adequately protect worker health. For example, since the current exposure limits were adopted, respirable crystalline silica exposure has been found to cause lung cancer and kidney disease at the levels currently permitted. Many employers are already implementing the necessary measures to protect their workers from silica exposure. The technology for most employers to meet the new standards is widely available and affordable. How will the rule protect workers? The rule significantly reduces the amount of silica dust that workers can be exposed to on the job. That means that employers will have

2 to implement controls and work practices that reduce workers exposure to silica dust. For most activities, that means that employers will have to ensure that silica dust is wetted down or vacuumed up before workers can breathe it in. Employers are required under the rule to limit access to high exposure areas, provide training, provide respiratory protection when controls are not enough to limit exposure, provide written exposure control plans, and measure exposures in some cases. Employers are also required to offer medical examinations to highly exposed workers. Workers who find out they have an illness, such as lung disease, can use that information to make employment or lifestyle decisions to protect their health. How will OSHA help employers comply with the rule to protect their workers? The rule provides flexibility to help employers especially small businesses protect workers from silica exposure, with staggered compliance dates to ensure sufficient time to meet the requirements. Employers have from one to five years to get the right protections in place. The rule includes special flexibility for the construction industry. For the most common tasks in construction, OSHA has spelled out exactly how to best protect workers. If employers follow those specifications, they can be sure that they are providing their workers with the required level of protection. If they have better ideas about how to provide protection, they can do that too as long as they make sure that their methods effectively reduce their workers exposure to silica dust. What industries are affected? Affected industries include: Construction Glass manufacturing Pottery products Structural clay products Concrete products Foundries Dental laboratories Paintings and coatings Jewelry production Refractory products Ready-mix concrete Cut stone and stone products Abrasive blasting in maritime, construction, and general industry Refractory furnace installation and repair Railroad transportation Oil and gas operations Additional information Additional information on OSHA s silica rule can be found at OSHA can provide extensive help through a variety of programs, including technical assistance about effective safety and health programs, workplace consultations, and training and education. OSHA s On-site Consultation Program offers free and confidential occupational safety and health services to small and medium-sized businesses in all states and several territories across the country, with priority given to high-hazard worksites. On-site consultation services are separate from enforcement and do not result in penalties or citations. Consultants from state agencies or universities work with employers to identify workplace hazards, provide advice on compliance with OSHA standards, and assist in establishing and improving safety and health management systems. To locate the OSHA On-site Consultation Program nearest you, call OSHA (6742) or visit For more information on this and other healthrelated issues impacting workers, to report an emergency, fatality, inpatient hospitalization, or to file a confidential complaint, contact your nearest OSHA office, visit or call OSHA at OSHA (6742), TTY This is one in a series of informational fact sheets highlighting OSHA programs, policies or standards. It does not impose any new compliance requirements. For a comprehensive list of compliance requirements of OSHA standards or regulations, refer to Title 29 of the Code of Federal Regulations. This information will be made available to sensory-impaired individuals upon request. The voice phone is (202) ; teletypewriter (TTY) number: (877) DSG FS /2016

3 Frequently Asked Questions: Respirable Crystalline Silica Rule Background and Health Impacts What is crystalline silica? Crystalline silica is a common mineral found in many naturally occurring materials and used in many industrial products and at construction sites. Materials like sand, concrete, stone and mortar contain crystalline silica. Crystalline silica is also used to make products such as glass, pottery, ceramics, bricks, concrete and artificial stone. Industrial sand used in certain operations, such as foundry work and hydraulic fracturing (fracking), is also a source of crystalline silica exposure. Amorphous silica, such as silica gel, is not crystalline silica. How can exposure to crystalline silica affect workers health? Inhaling very small ( respirable ) crystalline silica particles, causes multiple diseases, including silicosis, an incurable lung disease that can lead to disability and death. Respirable crystalline silica also causes lung cancer, chronic obstructive pulmonary disease (COPD), and kidney disease. Who is at risk from exposure to crystalline silica? Around 2.3 million workers are exposed to crystalline silica on the job. Simply being near sand or other silica-containing materials is not hazardous. The hazard exists when specific activities create respirable dust that is released into the air. Respirable crystalline silica very small particles typically at least 100 times smaller than ordinary sand found on beaches or playgrounds is generated by high-energy operations like cutting, sawing, grinding, drilling and crushing stone, rock, concrete, brick, block and mortar; or when using industrial sand. Activities such as abrasive blasting with sand; sawing brick or concrete; sanding or drilling into concrete walls; grinding mortar; manufacturing brick, concrete blocks, or ceramic products; and cutting or crushing stone generates respirable dust. What is the relationship between silica exposure and lung cancer? There is strong scientific evidence showing that exposure to respirable crystalline silica can increase a person s risk of developing lung cancer. The World Health Organization s International Agency for Research on Cancer the leading international voice on cancer causation and the National Institutes of Health s National Toxicology Program have conducted extensive reviews of the scientific literature and have designated crystalline silica as a known human carcinogen. The American Cancer Society has adopted the WHO and NIH s determinations. More than 50 peer-reviewed epidemiological studies that OSHA evaluated for this rulemaking have examined the link between silica exposure and lung cancer in at least 10 industries. In particular, several studies of workers in specific industrial sectors support the link between exposure to respirable crystalline silica and lung cancer among workers. Page 1 of 9

4 How will the crystalline silica rule protect workers health? The new rule requires that employers use engineering controls such as ventilation and wet methods for cutting and sawing crystalline silica-containing materials to reduce workers exposure to silica dust. Once the full effects of the rule are realized, OSHA expects it to prevent 600 deaths a year from silica-related diseases such as silicosis, lung cancer, other respiratory diseases and kidney disease and to prevent more than 900 new cases of silicosis each year. Need for a Silica Rule Why is OSHA issuing a new crystalline silica rule? OSHA s previous permissible exposure limits (PELs) for silica were outdated, inconsistent and did not adequately protect worker health. The previous PELs were based on studies from the 1960s and earlier that did not reflect more recent scientific evidence showing that low-level exposures to silica cause serious health effects, including lung cancer. In the 45 years since the previous PELs were established, the U.S. National Toxicology Program, the International Agency for Research on Cancer, and the National Institute for Occupational Safety and Health have all identified respirable crystalline silica as a human carcinogen. Previous construction and shipyard PELs were based on an old method of measuring worker exposures to silica that is not used today. Those previous limits are inconsistent, allowing permissible levels for construction and shipyards to be more than twice as high as levels in general industry. The revised rule will reduce the risk of disease among workers who inhale respirable crystalline silica and provide the same protection for all workers covered. There is evidence of a decline of silicosis cases in recent years. Why is the rule necessary if the silicosis problem in the U.S. seems to be going away? Silicosis deaths have declined in recent years but the problem remains serious. From 2005 through 2014, silicosis was listed as the underlying or a contributing cause of death on over 1,100 death certificates in the United States, 1 but most deaths from silicosis go undiagnosed and unreported. Also, those numbers of silicosis deaths do not include additional deaths from other silica-related diseases such as COPD, lung cancer and kidney disease. While the number of silicosis cases has declined over the past several decades, it is still a very serious workplace health problem. In fact, more workers died from silicosis in 2014 than in fires, or from being caught in or crushed by collapsing materials, such as in trench and structure collapses. 2 1 Centers for Disease Control and Prevention, National Center for Health Statistics. Multiple Cause of Death on CDC WONDER Online Database, released Data are from the Multiple Cause of Death Files, , as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program. Accessed at on Mar 7, :33:51 PM 2 Bureau of Labor Statistics (2014). Fatal occupational injuries by event or exposure for all fatal injuries and major private industrial sector, all United States, Page 2 of 9

5 Unless action is taken, new cases of silicosis could increase as workers are being exposed to respirable crystalline silica in some newer industries such as hydraulic fracturing and artificial stone countertop fabrication. What is the new permissible exposure limit (PEL)? The PEL limits worker exposures to 50 micrograms of respirable crystalline silica per cubic meter of air (μg/m 3 ), averaged over an eight-hour day. This level is the same for all workplaces covered by the standard (general industry/maritime and construction), and is roughly 50 percent of the previous PEL for general industry, and roughly 20 percent of the previous PEL for construction and shipyards. The National Institute for Occupational Safety and Health (NIOSH) first recommended this exposure limit to OSHA over 40 years ago, and the American Public Health Association has also recommended that OSHA adopt this PEL. The American Conference of Governmental Industrial Hygienists recommends an even lower exposure limit of 25 μg/m 3 of air, averaged over an eighthour day. OSHA established a PEL of 50 μg/m 3 because the agency determined that occupational exposure to respirable crystalline silica at the previous PELs resulted in a significant risk of developing or dying from silicosis and dying from lung cancer, other lung diseases, or kidney disease, and that compliance with a 50 μg/m 3 PEL would substantially reduce that risk. OSHA also finds significant risk remaining at the new PEL, but considers a PEL of 50 μg/m 3 to be the lowest level that can reasonably be achieved through use of engineering controls and work practices in most affected operations. Impacts on Industry What industries will be affected by the rule? The main industries affected include: Construction Glass manufacturing Pottery products Structural clay products Concrete products Foundries Dental laboratories Paintings and coatings Jewelry production Refractory products Landscaping Ready-mix concrete Cut stone and stone products Abrasive blasting in: o Maritime work o Construction o General industry Refractory furnace installation and repair Railroads Hydraulic fracturing for gas and oil Asphalt products manufacturing Page 3 of 9

6 How many workplaces will be affected by the rule? Approximately 676,000 workplaces will be affected, including in construction and in general industry and maritime. How many workers will be affected by the rule? About 2.3 million workers are exposed to respirable crystalline silica in their workplaces. The majority of these workers, about 2 million, are in the construction industry. What is the economic impact of the rule? The rule is estimated to provide average annual net benefits over the next 60 years of $3.8 to $7.7 billion. The total annualized cost of the rule is just over $1 billion dollars. The rule is expected to result in annual costs of about $1,524 for the average workplace covered by the rule. The annual cost to a firm with fewer than twenty employees will be less, averaging about $560. Based on OSHA s analysis, the economic impact of the silica rule on most affected firms, including small businesses, will be minor. Why does the total compliance cost of the rule appear to be so high? The standards for general industry and construction are among the broadest that OSHA has issued, in terms of the number of industry sectors and establishments potentially affected. It potentially affects 2.3 million workers and 676,000 establishments. The costs are thus spread over a large number of affected establishments and workers. OSHA s economic analysis indicates that the silica rule will not have a significant economic impact on firms, nor a significant effect on jobs due to implementation of the rules. The aggregate costs are more than offset by the potential benefits to society in terms of reduced costs associated with preventing silica-related illnesses and deaths. How will the rule impact jobs? According to a study conducted by Inforum, a well-recognized macroeconomics modeling firm based at the University of Maryland, the rule will have a negligible (but positive) net effect on overall U.S. employment. How were small businesses included in design and evaluation of the rule? OSHA consulted with small businesses through the normal Small Business Regulatory Enforcement Fairness Act (SBREFA) process and as part of its extensive analysis of the impacts on small businesses. Before issuing its proposed silica rule, OSHA convened a Small Business Advocacy Review Panel in accordance with SBREFA. After issuing the proposed rule, OSHA gave members of the public, including small businesses, the opportunity to express their concerns about the Page 4 of 9

7 rulemaking through written comments, testimony at a public hearing, and submission of data and post-hearing briefs. OSHA considered all information it received from the SBREFA panel, in addition to comments and testimony on the proposed rule, to inform the final rule and evaluate its impacts on small businesses. In Table VII-40 in the preamble to the rule, OSHA addresses nearly 50 recommendations from small business representatives. Many of these resulted in changes to the rule or underlying cost, benefit, and economic analysis. Rule Requirements How can silica exposures be controlled to keep exposure at or below the PEL? Employers must use engineering controls and work practices as the primary way keep exposures at or below the PEL. Engineering controls include wetting down work operations or using local exhaust ventilation (such as vacuums) to keep silica-containing dust out of the air and out of workers lungs. Another control method that may work well is enclosing an operation ( process isolation ). Examples of work practices to control silica exposures include wetting down dust before sweeping it up or using the water flow rate recommended by the manufacturer for a tool with water controls. Respirators are only allowed when engineering and work practice controls cannot maintain exposures at or below the PEL. For construction, the standard includes Table 1, a list of common construction tasks along with exposure control methods and work practices that work well for those tasks and can be used to comply with the requirements of the standard. Why can t silica-exposed workers just wear respirators all the time? Respirators are not as protective as engineering controls, and they aren t always as practical either. Unless respirators are selected for each worker, individually fitted and periodically refitted, and regularly maintained, and unless filters and other parts are replaced as necessary, workers will continue to be exposed to silica. In many cases, workers using only respirators would also have to wear more extensive and expensive protection. Even when respirators are selected, fitted, and maintained correctly, they must be worn consistently and correctly by workers to be effective. Respirators can also be uncomfortable, especially in hot weather, and cannot be used by some workers. Page 5 of 9

8 What is Table 1: Specified Exposure Control Methods When Working with Materials Containing Crystalline Silica? Table 1 is a flexible compliance option that effectively protects workers from silica exposures. It identifies 18 common construction tasks that generate high exposures to respirable crystalline silica and for each task, specifies engineering controls, work practices, and respiratory protection that effectively protect workers. Employers who fully and properly implement the engineering controls, work practices, and respiratory protection specified for a task on Table 1 are not required to measure respirable crystalline silica exposures to verify that levels are at or below the PEL for workers engaged in the Table 1 task. OSHA developed Table 1 in response to stakeholders in the construction industry, who indicated the need for guidance and a standard that is different than a standard for general industry. Among the concerns of construction industry stakeholders were the impracticality of exposure monitoring based on short duration of task and constantly changing conditions, such as weather, job sites and materials. Are the air sampling methods used to detect and measure silica reliable? Yes, worker exposures to silica at the new PEL and action level can be reliably measured using existing sampling and analytical methods. Moreover, to improve reliability of silica measurements, employers must ensure that their silica samples are analyzed by laboratories that meet the qualifications and use methods specified in Appendix A of the standard. OSHA has carefully reviewed the available science and expert testimony contained in the rulemaking record on the ability of modern sampling and analytical methods to reliably measure respirable crystalline silica at the new PEL and action level. Published OSHA, NIOSH, and MSHA methods for analyzing respirable crystalline silica are able to measure concentrations at the new PEL and action level with acceptable precision, based on analyses of quality control samples and on studies conducted when those methods were developed in the 1970s. There are high-flow dust samplers now available that can collect more airborne dust, and more silica, than other samplers commonly used. Collecting more dust means that laboratories can measure the amount of silica in the dust with greater precision. Page 6 of 9

9 Why are construction employers required to implement engineering and work practice controls a year before laboratories are required to meet specifications for analyzing air samples? There are approximately 40 laboratories in the U.S. that already meet the sample analysis requirements in the final rule. Demand for laboratory analysis of construction industry samples is likely to be modest because OSHA expects most construction employers to implement the specified exposure control measures in Table 1; therefore they will not be required to conduct exposure assessments. The small portion of construction employers that do not implement Table 1 will need to perform air monitoring, but they will be able to obtain reliable measurements of their employees exposures from those laboratories. Employers in general industry and maritime, who are required to conduct exposure assessments, have an additional year to come into compliance. What is the purpose of medical surveillance? The purpose of medical surveillance is, when reasonably possible, to: Identify adverse health effects associated with respirable crystalline silica exposure so that appropriate actions can be taken. Determine if an employee has any condition, such as a lung disease, that might make him or her more sensitive to respirable crystalline silica exposure, Determine the employee s fitness to use respirators. In response to the information gained through medical surveillance, employees can take actions to improve their health, such as making job choices to reduce exposures, wearing a respirator for extra protection, or making personal lifestyle or health decisions, such as quitting smoking or getting flu shots. Why are the results of medical surveillance only given to the worker and not the employer? The employer receives the physician or other licensed health care professional s recommended limitations on respirator use, which is vitally important information that the employer needs to protect the worker because those who are not fit to wear a respirator but wear one can be at risk of sudden incapacitation or death. Other findings of the medical examination are only given to the employee because many employees and physicians testified that if employers received the results of the examination, many employees would not participate in medical surveillance because they feared discrimination or retaliation. Employers do not need medical findings because they should base employee protections on exposure levels and how well controls are working. On the other hand, employees need the results of medical examinations to manage their health. Page 7 of 9

10 Compliance Dates When must employers comply with the standard for general/industry and maritime? For all operations in general industry and maritime, other than hydraulic fracturing operations in the oil and gas industry: Employers are required to comply with all obligations of the standard, with the exception of the action level trigger for medical surveillance, by June 23, Employers are required to offer medical examinations to employees exposed above the PEL for 30 or more days a year beginning on June 23, Employers are required to offer medical examinations to employees exposed at or above the action level for 30 or more days a year beginning on June 23, For hydraulic fracturing operations in the oil and gas industry: Employers are required to comply with all obligations of the standard, except for engineering controls and the action level trigger for medical surveillance, by June 23, Employers are required to comply with requirements for engineering controls to limit exposures to the new PEL by June 23, From June 23, 2018 through June 23, 2021, employers can continue to have employees wear respirators if their exposures exceed the PEL. Employers are required to offer medical examinations to employees exposed above the PEL for 30 or more days beginning on June 23, Employers are required to offer medical examinations to employees exposed at or above the action level for 30 or more days a year beginning on June 23, Why is there a different compliance date for the hydraulic fracturing industry? Because controls for respirable crystalline silica in hydraulic fracturing are still in development, the rule allows hydraulic fracturing employers additional time to implement engineering controls to take advantage of emerging technologies. Those employers do not have to implement engineering controls to limit exposures to the new PEL until June 23, 2021, three years later than other general industry and maritime employers. From June 23, 2018 to June 23, 2021, hydraulic fracturing employers can continue to have employees use respirators when exposures exceed the PEL. When must employers comply with the standard for construction? Employers are required to comply with all obligations of the standard (except methods of sample analysis) by June 23, Employers are required to comply with methods of sample analysis by June 23, Page 8 of 9

11 State Plans and Compliance Assistance Will states with OSHA-approved programs adopt the standards? Yes. States with OSHA-approved state plans have six months to adopt standards that are at least as effective as Federal OSHA standards. Many state plans adopt standards identical to OSHA, but some state plans may have different or more stringent requirements. What resources are available to help small businesses and other employers comply with the standards? OSHA recognizes that most employers want to keep their employees safe and protect them from workplace hazards. We therefore provide extensive compliance assistance through our Compliance Assistance Specialists, website, publications, webinars, and training programs, many of which are geared toward small and mid-sized employers. For silica, OSHA will develop a Small Entity Compliance Guide, fact sheets and other compliance assistance resources. For more information, see the Crystalline Silica Rulemaking page. OSHA's On-site Consultation Program provides professional, high-quality, individualized assistance to small businesses at no cost. This service, which is provided by consultants from state agencies or universities, is separate and independent from enforcement programs in federal or state OSHA s programs, and provides free and confidential workplace safety and health evaluations and advice to small and medium-sized businesses. In FY 2015, the On-site Consultation Program conducted more than 27,800 free visits to small and medium-sized business worksites, helping to remove more than 3.5 million workers from hazards nationwide. Additional information about the silica rule is available at The website provides additional information on the hazards of occupational exposure to silica with links to fact sheets and an updated silica safety and health topics page, and further explains the provisions of the final rule. Page 9 of 9

12 Appendix A to Methods of sample analysis. This appendix specifies the procedures for analyzing air samples for respirable crystalline silica, as well as the quality control procedures that employers must ensure that laboratories use when performing an analysis required under 29 CFR (d)(2)(v). Employers must ensure that such a laboratory: 1. Evaluates all samples using the procedures specified in one of the following analytical methods: OSHA ID-142; NMAM 7500; NMAM 7602; NMAM 7603; MSHA P-2; or MSHA P- 7; 2. Is accredited to ANS/ISO/IEC Standard 17025:2005 with respect to crystalline silica analyses by a body that is compliant with ISO/IEC Standard 17011:2004 for implementation of quality assessment programs; 3. Uses the most current National Institute of Standards and Technology (NIST) or NIST traceable standards for instrument calibration or instrument calibration verification; 4. Implements an internal quality control (QC) program that evaluates analytical uncertainty and provides employers with estimates of sampling and analytical error; 5. Characterizes the sample material by identifying polymorphs of respirable crystalline silica present, identifies the presence of any interfering compounds that might affect the analysis, and makes any corrections necessary in order to obtain accurate sample analysis; and 6. Analyzes quantitatively for crystalline silica only after confirming that the sample matrix is free of uncorrectable analytical interferences, corrects for analytical interferences, and uses a method that meets the following performance specifications: 6.1 Each day that samples are analyzed, performs instrument calibration checks with standards that bracket the sample concentrations; 1

13 6.2 Uses five or more calibration standard levels to prepare calibration curves and ensures that standards are distributed through the calibration range in a manner that accurately reflects the underlying calibration curve; and 6.3 Optimizes methods and instruments to obtain a quantitative limit of detection that represents a value no higher than 25 percent of the PEL based on sample air volume. 2

14 Appendix B to Medical Surveillance Guidelines. Introduction The purpose of this Appendix is to provide medical information and recommendations to aid physicians and other licensed health care professionals (PLHCPs) regarding compliance with the medical surveillance provisions of the respirable crystalline silica standard (29 CFR ). Appendix B is for informational and guidance purposes only and none of the statements in Appendix B should be construed as imposing a mandatory requirement on employers that is not otherwise imposed by the standard. Medical screening and surveillance allow for early identification of exposure-related health effects in individual employee and groups of employees, so that actions can be taken to both avoid further exposure and prevent or address adverse health outcomes. Silica-related diseases can be fatal, encompass a variety of target organs, and may have public health consequences when considering the increased risk of a latent tuberculosis (TB) infection becoming active. Thus, medical surveillance of silica-exposed employees requires that PLHCPs have a thorough knowledge of silica-related health effects. This Appendix is divided into seven sections. Section 1 reviews silica-related diseases, medical responses, and public health responses. Section 2 outlines the components of the medical surveillance program for employees exposed to silica. Section 3 describes the roles and responsibilities of the PLHCP implementing the program and of other medical specialists and public health professionals. Section 4 provides a discussion of considerations, including confidentiality. Section 5 provides a list of additional resources and Section 6 lists references. Section 7 provides sample forms for the written medical report for the employee, the written medical opinion for the employer and the written authorization. 1

15 1. Recognition of Silica-related Diseases Overview. The term silica refers specifically to the compound silicon dioxide (SiO 2 ). Silica is a major component of sand, rock, and mineral ores. Exposure to fine (respirable size) particles of crystalline forms of silica is associated with adverse health effects, such as silicosis, lung cancer, chronic obstructive pulmonary disease (COPD), and activation of latent TB infections. Exposure to respirable crystalline silica can occur in industry settings such as foundries, abrasive blasting operations, paint manufacturing, glass and concrete product manufacturing, brick making, china and pottery manufacturing, manufacturing of plumbing fixtures, and many construction activities including highway repair, masonry, concrete work, rock drilling, and tuck-pointing. New uses of silica continue to emerge. These include countertop manufacturing, finishing, and installation (Kramer et al. 2012; OSHA 2015) and hydraulic fracturing in the oil and gas industry (OSHA 2012). Silicosis is an irreversible, often disabling, and sometimes fatal fibrotic lung disease. Progression of silicosis can occur despite removal from further exposure. Diagnosis of silicosis requires a history of exposure to silica and radiologic findings characteristic of silica exposure. Three different presentations of silicosis (chronic, accelerated, and acute) have been defined. Accelerated and acute silicosis are much less common than chronic silicosis. However, it is critical to recognize all cases of accelerated and acute silicosis because these are life-threatening illnesses and because they are caused by substantial overexposures to respirable crystalline silica. Although any case of silicosis indicates a breakdown in prevention, a case of acute or accelerated silicosis implies current high exposure and a very marked breakdown in prevention. In addition to silicosis, employees exposed to respirable crystalline silica, especially those with accelerated or acute silicosis, are at increased risks of contracting active TB and other 2

16 infections (ATS 1997; Rees and Murray 2007). Exposure to respirable crystalline silica also increases an employee s risk of developing lung cancer, and the higher the cumulative exposure, the higher the risk (Steenland et al. 2001; Steenland and Ward 2014). Symptoms for these diseases and other respirable crystalline silica-related diseases are discussed below Chronic Silicosis. Chronic silicosis is the most common presentation of silicosis and usually occurs after at least 10 years of exposure to respirable crystalline silica. The clinical presentation of chronic silicosis is: Symptoms - shortness of breath and cough, although employees may not notice any symptoms early in the disease. Constitutional symptoms, such as fever, loss of appetite and fatigue, may indicate other diseases associated with silica exposure, such as TB infection or lung cancer. Employees with these symptoms should immediately receive further evaluation and treatment Physical Examination - may be normal or disclose dry rales or rhonchi on lung auscultation Spirometry - may be normal or may show only a mild restrictive or obstructive pattern Chest X-ray - classic findings are small, rounded opacities in the upper lung fields bilaterally. However, small irregular opacities and opacities in other lung areas can also occur. Rarely, eggshell calcifications in the hilar and mediastinal lymph nodes are seen Clinical Course - chronic silicosis in most cases is a slowly progressive disease. Under the respirable crystalline silica standard, the PLHCP is to recommend that employees with a 1/0 category X-ray be referred to an American Board Certified Specialist in Pulmonary Disease 3

17 or Occupational Medicine. The PLHCP and/or Specialist should counsel employees regarding work practices and personal habits that could affect employees respiratory health Accelerated Silicosis. Accelerated silicosis generally occurs within 5-10 years of exposure and results from high levels of exposure to respirable crystalline silica. The clinical presentation of accelerated silicosis is: Symptoms - shortness of breath, cough, and sometimes sputum production. Employees with exposure to respirable crystalline silica, and especially those with accelerated silicosis, are at high risk for activation of TB infections, atypical mycobacterial infections, and fungal superinfections. Constitutional symptoms, such as fever, weight loss, hemoptysis (coughing up blood), and fatigue may herald one of these infections or the onset of lung cancer Physical Examination - rales, rhonchi, or other abnormal lung findings in relation to illnesses present. Clubbing of the digits, signs of heart failure, and cor pulmonale may be present in severe lung disease Spirometry - restrictive or mixed restrictive/obstructive pattern Chest X-ray - small rounded and/or irregular opacities bilaterally. Large opacities and lung abscesses may indicate infections, lung cancer, or progression to complicated silicosis, also termed progressive massive fibrosis Clinical Course - accelerated silicosis has a rapid, severe course. Under the respirable crystalline silica standard, the PLHCP can recommend referral to a Board Certified Specialist in either Pulmonary Disease or Occupational Medicine, as deemed appropriate, and referral to a Specialist is recommended whenever the diagnosis of accelerated silicosis is being considered. 4

18 1.4. Acute Silicosis. Acute silicosis is a rare disease caused by inhalation of extremely high levels of respirable crystalline silica particles. The pathology is similar to alveolar proteinosis with lipoproteinaceous material accumulating in the alveoli. Acute silicosis develops rapidly, often, within a few months to less than 2 years of exposure, and is almost always fatal. The clinical presentation of acute silicosis is as follows: Symptoms - sudden, progressive, and severe shortness of breath. Constitutional symptoms are frequently present and include fever, weight loss, fatigue, productive cough, hemoptysis (coughing up blood), and pleuritic chest pain Physical Examination - dyspnea at rest, cyanosis, decreased breath sounds, inspiratory rales, clubbing of the digits, and fever Spirometry - restrictive or mixed restrictive/obstructive pattern Chest X-ray - diffuse haziness of the lungs bilaterally early in the disease. As the disease progresses, the ground glass appearance of interstitial fibrosis will appear Clinical Course - employees with acute silicosis are at especially high risk of TB activation, nontuberculous mycobacterial infections, and fungal superinfections. Acute silicosis is immediately life-threatening. The employee should be urgently referred to a Board Certified Specialist in Pulmonary Disease or Occupational Medicine for evaluation and treatment. Although any case of silicosis indicates a breakdown in prevention, a case of acute or accelerated silicosis implies a profoundly high level of silica exposure and may mean that other employees are currently exposed to dangerous levels of silica COPD. COPD, including chronic bronchitis and emphysema, has been documented in silica-exposed employees, including those who do not develop silicosis. Periodic spirometry tests are performed to evaluate each employee for progressive changes consistent with the 5

19 development of COPD. In addition to evaluating spirometry results of individual employees over time, PLHCPs may want to be aware of general trends in spirometry results for groups of employees from the same workplace to identify possible problems that might exist at that workplace. (See Section 2 of this Appendix on Medical Surveillance for further discussion.) Heart disease may develop secondary to lung diseases such as COPD. A recent study by Liu et al noted a significant exposure-response trend between cumulative silica exposure and heart disease deaths, primarily due to pulmonary heart disease, such as cor pulmonale Renal and Immune System. Silica exposure has been associated with several types of kidney disease, including glomerulonephritis, nephrotic syndrome, and end stage renal disease requiring dialysis. Silica exposure has also been associated with other autoimmune conditions, including progressive systemic sclerosis, systemic lupus erythematosus, and rheumatoid arthritis. Studies note an association between employees with silicosis and serologic markers for autoimmune diseases, including antinuclear antibodies, rheumatoid factor, and immune complexes (Jalloul and Banks 2007; Shtraichman et al. 2015) TB and Other Infections. Silica-exposed employees with latent TB are 3 to 30 times more likely to develop active pulmonary TB infection (ATS 1997; Rees and Murray 2007). Although respirable crystalline silica exposure does not cause TB infection, individuals with latent TB infection are at increased risk for activation of disease if they have higher levels of respirable crystalline silica exposure, greater profusion of radiographic abnormalities, or a diagnosis of silicosis. Demographic characteristics, such as immigration from some countries, are associated with increased rates of latent TB infection. PLHCPs can review the latest Centers for Disease Control and Prevention (CDC) information on TB incidence rates and high risk populations online (See Section 5 of this Appendix). Additionally, silica-exposed employees are 6

20 at increased risk for contracting nontuberculous mycobacterial infections, including Mycobacterium avium-intracellulare and Mycobacterium kansaii Lung Cancer. The National Toxicology Program has listed respirable crystalline silica as a known human carcinogen since 2000 (NTP 2014). The International Agency for Research on Cancer (2012) has also classified silica as Group 1 (carcinogenic to humans). Several studies have indicated that the risk of lung cancer from exposure to respirable crystalline silica and smoking is greater than additive (Brown 2009; Liu et al. 2013). Employees should be counseled on smoking cessation. 2. Medical Surveillance. PLHCPs who manage silica medical surveillance programs should have a thorough understanding of the many silica-related diseases and health effects outlined in Section 1 of this Appendix. At each clinical encounter, the PLHCP should consider silica-related health outcomes, with particular vigilance for acute and accelerated silicosis. In this Section, the required components of medical surveillance under the respirable crystalline silica standard are reviewed, along with additional guidance and recommendations for PLHCPs performing medical surveillance examinations for silica-exposed employees History The respirable crystalline silica standard requires the following: A medical and work history, with emphasis on: past, present, and anticipated exposure to respirable crystalline silica, dust, and other agents affecting the respiratory system; any history of respiratory system dysfunction, including signs and symptoms of respiratory disease (e.g., shortness of breath, cough, wheezing); history of TB; and smoking status and history Further, the employer must provide the PLHCP with the following information: 7

21 A description of the employee s former, current, and anticipated duties as they relate to the employee s occupational exposure to respirable crystalline silica; The employee s former, current, and anticipated levels of occupational exposure to respirable crystalline silica; A description of any personal protective equipment used or to be used by the employee, including when and for how long the employee has used or will use that equipment; and Information from records of employment-related medical examinations previously provided to the employee and currently within the control of the employer Additional guidance and recommendations: A history is particularly important both in the initial evaluation and in periodic examinations. Information on past and current medical conditions (particularly a history of kidney disease, cardiac disease, connective tissue disease, and other immune diseases), medications, hospitalizations and surgeries may uncover health risks, such as immune suppression, that could put an employee at increased health risk from exposure to silica. This information is important when counseling the employee on risks and safe work practices related to silica exposure Physical Examination The respirable crystalline silica standard requires the following: A physical examination, with special emphasis on the respiratory system. The physical examination must be performed at the initial examination and every three years thereafter Additional guidance and recommendations: Elements of the physical examination that can assist the PHLCP include: an examination of the cardiac system, an extremity 8

22 examination (for clubbing, cyanosis, edema, or joint abnormalities), and an examination of other pertinent organ systems identified during the history TB Testing The respirable crystalline silica standard requires the following: Baseline testing for TB on initial examination Additional guidance and recommendations: Current CDC guidelines (See Section 5 of this Appendix) should be followed for the application and interpretation of Tuberculin skin tests (TST). The interpretation and documentation of TST reactions should be performed within 48 to 72 hours of administration by trained PLHCPs PLHCPs may use alternative TB tests, such as interferon-γ release assays (IGRAs), if sensitivity and specificity are comparable to TST (Mazurek et al. 2010; Slater et al. 2013). PLHCPs can consult the current CDC guidelines for acceptable tests for latent TB infection The silica standard allows the PLHCP to order additional tests or test at a greater frequency than required by the standard, if deemed appropriate. Therefore, PLHCPs might perform periodic (e.g., annual) TB testing as appropriate, based on employees risk factors. For example, according to the American Thoracic Society (ATS), the diagnosis of silicosis or exposure to silica for 25 years or more are indications for annual TB testing (ATS 1997). PLHCPs should consult the current CDC guidance on risk factors for TB (See Section 5 of this Appendix) Employees with positive TB tests and those with indeterminate test results should be referred to the appropriate agency or specialist, depending on the test results and clinical 9

23 picture. Agencies, such as local public health departments, or specialists, such as a pulmonary or infectious disease specialist, may be the appropriate referral. Active TB is a nationally notifiable disease. PLHCPs should be aware of the reporting requirements for their region. All States have TB Control Offices that can be contacted for further information. (See Section 5 of this Appendix for links to CDC s TB resources and State TB Control Offices.) The following public health principles are key to TB control in the U.S. (ATS- CDC-IDSA 2005): (1) Prompt detection and reporting of persons who have contracted active TB; (2) Prevention of TB spread to close contacts of active TB cases; (3) Prevention of active TB in people with latent TB through targeted testing and treatment; and (4) Identification of settings at high risk for TB transmission so that appropriate infection-control measures can be implemented Pulmonary Function Testing The respirable crystalline silica standard requires the following: Pulmonary function testing must be performed on the initial examination and every three years thereafter. The required pulmonary function test is spirometry and must include forced vital capacity (FVC), forced expiratory volume in one second (FEV 1 ), and FEV 1 /FVC ratio. Testing must be administered by a spirometry technician with a current certificate from a National Institute for Occupational Health and Safety (NIOSH)-approved spirometry course Additional guidance and recommendations: Spirometry provides information about individual respiratory status and can be used to track an employee s respiratory status over time or as a surveillance tool to follow individual and group respiratory function. For quality 10