In late August, the Labor Department’s Occupational Safety and Health Administration (OSHA) proposed a long-awaited rule that is intended to limit workers’ exposure to crystalline silica. OSHA claims that exposure to crystalline silica kills hundreds of workers and sickens thousands more each year through lung cancer, silicosis, chronic obstructive pulmonary disease, and kidney disease.

The proposed rule is especially relevant to companies involved in hydraulic fracturing, as the agency issued a “hazard alert” in June 2012 warning of worker exposure to silica during fracturing operations. According to the Hazard Alert, industry’s use of proppants to keep fractures open and maintain the flow of hydrocarbons in hydraulically fractured wells can lead to exposures of respirable crystalline silica. OSHA asserts that approximately 25,440 oil and gas workers are currently exposed to silica dust and 16,056 are exposed to levels above the proposed permissible exposure limit of 50 micrograms per cubic meter.

  • The proposed rule consists of two standards for exposure protection, one for general industry and maritime, and the other for construction. The general industry/maritime standard includes provisions for employers to:
  • Measure the amount of silica to which workers are exposed if it may be at or above 25 micrograms per cubic meter of air, averaged over an 8-hour day;
  • Protect workers from exposures above the proposed permissible exposure limit (PEL) of 50 micrograms per cubic meter of air, averaged over an 8-hour day (the current limit is 100 micrograms/m3);
  • Limit workers’ access to areas where they could be exposed above the PEL;
  • Use dust controls to protect workers from exposures above the PEL;
  • Provide respirators to workers when dust control measures cannot prevent exposures above the PEL;
  • Offer medical exams every three years for workers exposed above the PEL for thirty or more days per year;
  • Train workers on operations that result in exposure and how to limit exposure;
  • Keep records of workers’ exposure and medical exams.

With assistance from Andrew McNamee