The Occupational Safety and Health Administration (OSHA) has released notice of a proposed rule to set new Permissible Exposure Limits (PELs) for respirable crystalline silica, among other requirements for controlling workplace exposure to silica. For all industries (general, construction, and maritime), the new rule would protect against silica exposure above the PEL of fifty micrograms per cubic meter of air (50 μg/m3), averaged over an eight-hour day.

The proposed rule also includes provisions for measuring how much silica workers are exposed to, limiting workers’ access to areas where silica exposures are high, using effective methods for reducing exposures, providing medical exams to workers with high silica exposures, and training workers about silica-related hazards and how to limit exposure.

OSHA would amend the current general industry standard, 29 C.F.R. § 1910.1000 “Air Contaminants,” by adding § 1910.1053 “Respirable Crystalline Silica.” This new standard would affect all industries except construction and agriculture. In construction, a new standard, 29 C.F.R. § 1926.1053 “Respirable Crystalline Silica,” would be added. Separate changes would be made to Part 1915 regarding shipyard employees, providing the same requirements as the general industry standard.

Under the new standards, OSHA would set a silica action level of twenty-five micrograms per cubic meter of air (25 μg/m3). An employer must assess exposure to employees when an employee will, or reasonably may, be exposed to respirable crystalline silica at the action level or above. Wherever an employee’s exposure to airborne concentrations of respirable silica is, or can reasonably be expected to be, in excess of the PEL, the employer shall establish and implement either a regulated area or a written access control plan. In addition to these measures, employers must offer free medical exams once every three years or more, if recommended by a physician, to employees who will be exposed above the PEL for thirty (30) or more days per year. Employers must also keep records of workers’ silica exposures and medical exams.

Under the proposed construction standard, an employer is not required to assess exposure to employees if the employer complies with Table 1 to the new standard, which provides the exact engineering, work practice control methods, and respiratory protection that must be used. Employers who abide by the Table 1 requirements must still ensure that employees are not exposed in excess of the PEL. Under the construction proposal, employers must comply with the same medical examination and record keeping requirements as the general industry standard.

According to OSHA, exposure to airborne silica dust occurs in operations involving cutting, sawing, drilling and crushing of concrete, brick, block and other stone products and in operations using sand products, such as in glass manufacturing, foundries and sand blasting.

OSHA will accept public comments on the proposed rule for 90 days following publication in the Federal Register, followed by public hearings. OSHA plans to begin holding public hearings on the silica rulemaking on March 4, 2014. OSHA has created a webpage with fact sheets and the proposed rule.