The Occupational Safety and Health Administration (OSHA) recently released its proposed rules for the regulation of respirable crystalline silica (“silica dust”). These proposed regulations have been greatly anticipated by many industries given the expansive use of materials such as quartz (which creates silica dust when cut or drilled) and the expense of engineering controls that OSHA has previously suggested for control of silica dust.

Most notably, OSHA’s proposed rules require that employers use dust controls – such as vacuum and water-integrated tools – to reduce employees’ exposure below the permissible exposure limits (PELs) unless doing so is demonstrably infeasible. This portion of the proposed rules prohibits mere reliance on respirators – the traditional method of complying with current PELs.

According to OSHA, the most severe exposures to silica dust generally occur during abrasive blasting with sand to remove paint and rust from bridges, tanks, concrete structures and other surfaces. Other construction activities that may result in severe exposure include: jack hammering, rock/well drilling, concrete mixing, concrete drilling, brick and concrete block cutting and sawing, tuck pointing, and tunneling operations, and hydraulic fracturing (“fracking”).

OSHA currently enforces PELs for silica dust in general industry, construction and shipyards. The current PELs were adopted in 1971 and have not been updated since then. OSHA’s current PELs for silica dust range from approximately 250 micrograms of silica dust per cubic meter of air (“µg/m3”) (for quartz silica) to 50 µg/m3 (for cristobalite and tridymite silica) and vary depending on the type of silica and the particular industry involved. See, e.g., 29 CFR §§ 1926.55 and 1910.1000.

OSHA is proposing a new, blanket PEL for all silica dust (quartz, cristobalite and tridymite) of 50 μg/m3, averaged over an 8-hour day, in all industry sectors covered by the rule. This is a significant reduction from the current PELs for quartz silica dust.

OSHA is also proposing the following major requirements under the new rules:

  • Employers must measure the amount of silica dust that workers are exposed to if it may be at or above an action level of 25 μg/m3;
  • Employers must prevent all silica dust exposures above the PEL of 50 μg/m3;
  • Employers must limit workers’ access to areas where they could be exposed to silica dust above the PEL;
  • Employers must utilize dust controls to protect workers from silica exposures above the PEL;
  • Employers must provide respirators to workers when dust controls cannot limit exposures to the PEL;
  • Employers must offer medical exams – including chest X-rays and lung function tests – every three years for workers exposed to silica dust above the PEL for 30 or more days per year;
  • Employers must provide training to workers on operations that result in silica dust exposure and ways to limit exposure; and
  • Employers must keep records of all workers’ silica dust exposure and medical exams.

The foregoing proposed regulations come on the heels of OSHA’s June 2012 “Hazard Alert” on silica dust in hydraulic fracturing, which specifically identified risks of silica exposure in hydraulic fracturing. The 2012 Hazard Alert was the result of a joint study conducted with the National Institute for Occupational Safety and Health (NIOSH) in 2012, whereby NIOSH collected 116 full shift air samples at 11 hydraulic fracturing sites in five states (Arkansas, Colorado, North Dakota, Pennsylvania and Texas). Many air samples showed silica levels in and around the dust generation points above defined occupational exposure limits. More recently, however, a 2013 study conducted by NIOSH found that the concentration of silica dust exceeded the PELs at all 11 hydraulic fracturing sites tested – the results of which were announced by the American Industrial Hygiene Association on July 31, 2013.

Notwithstanding the purposes behind OSHA’s proposed rules, recent studies conducted by the Centers for Disease Control and Prevention (CDC) indicate that mortality associated with silica-related disease is very rare and has greatly declined in recent history. During 1968 through 2002, the CDC reported that the number of silicosis deaths decreased by 93%. A more recent CDC study covering the years of 1998 through 2007 concluded that the mortality rate had declined even further: falling to .69 for every 1 million people (.0000069%).

OSHA is currently soliciting comments on these proposed rules; the comment period will close within a few weeks.