On Dec. 22, the U.S. Court of Appeals for the District of Columbia Circuit upheld OSHA’s silica dust standard. The Court also ordered OSHA to explain why it left out medical removal provisions that would have allowed doctors to call for the evacuation of sick workers from environments with silica under certain conditions.

Crystalline silica, a mineral often found in the earth’s crust, is a component of soil, sand and granite. According to OSHA, about 2.3 million people in the U.S. are exposed to silica dust at work through tasks such as abrasive blasting, drilling and brick and pavement manufacturing. Those exposed to silica dust, which is classified as a human lung carcinogen and has granules 100 times smaller than sand, could face serious illness, from silicosis (a sometimes-fatal lung disease resulting from scar tissue formed as a result of silica exposure) to tuberculosis.   

The Appeals Court decision came after several industry groups, including the U.S. Chamber of Commerce, aggressively challenged the Occupational Exposure to Respirable Crystalline Silica rule, which was originally issued in March 2016 but not yet fully enforced. Many industry arguments hinged on the idea that OSHA did not have sufficient evidence to support its assertion that the silica standard would reduce workers’ medical risk and be economically and technologically feasible. For example, industry organizations questioned OSHA’s finding that limiting workers’ silica exposure at 50 micrograms per cubic meter could reduce incidents of illness. They also questioned the feasibility of enforcing the standard within three particular work environments – foundries, hydraulic fracturing and construction – due to the variability of their airborne silica levels, which industry groups say would require employers to keep levels well below OSHA requirements.

The standard requires contractors to take several key actions to limit workers’ silica exposure, including developing a written control plan, designating someone to implement the plan, providing medical exams every three years to employees exposed to silica who wear respirators for 30 days or more annually and training workers. .