OSHA has announced a long-awaited proposal it says will save some 700 lives and prevent 1,600 new cases of silicosis each year. The changes would replace 40-year-old permissible exposure limits (PELs) OSHA says are dangerously out of date.

Exposure to airborne silica dust affects those in cutting, sawing, drilling, and crushing of concrete and stone products. Construction workers in particular are often exposed to silica on the job. Also at risk are workers in operations that use sand, like glass manufacturing, foundries, and sand blasting.

Silica exposure has also been identified as an occupational hazard at oil and natural gas hydraulic fracturing (fracking) sites. A mixture of silica, water, and chemicals helps keep the underground fractures open so that oil and natural gas can flow out.

The plan to reduce exposure has met with strong opposition from industry groups, and the proposal was on hold at the Office of Management and Budget (OMB) from early 2011 until this week.

What compliance will mean

Over 2 million workers are exposed to crystalline silica dust, a known human carcinogen. Exposure to the tiny particles is linked to silicosis, as well as lung cancer, kidney disease, chronic obstructive pulmonary disease (CPOD), tuberculosis, and other serious conditions.

The current PEL for general industry and maritime workers is 100 micrograms per cubic meter of air and 250 for construction. The proposal would reduce the limit in all areas to 50 micrograms, but the proposal includes two separate standards, one for construction and the other for general industry and maritime workplaces. The separate standards are intended not to provide different levels of protection, but to give employers flexibility in selecting protection methods that are best suited to the conditions at their facilities.

During a press conference to announce the proposed rule, OSHA administrator Dr. David Michaels stated, “Every year, many exposed workers not only lose their ability to work, but also to breathe.” Michaels introduced a 48-year-old foundry worker who says that although his employer emphasized slip hazards and other hazards, the “unseen dangers” of silica were never made clear. The employee called the effects of his exposure “devastating.” Even walking while talking on the cell phone is difficult due to silica-related lung damage, he said.

Michaels encouraged stakeholders to share their views of the proposal and said OSHA will hold hearings beginning in March in Washington, D.C. “We know how to lower silica exposure,” he added. “Many employers use commonsense, inexpensive control measures.” These include keeping material wet so dust doesn’t become airborne and using a vacuum to collect dust before it can be inhaled.

The new rules are designed to give employers flexibility in meeting the requirements. Estimates for the costs and benefits of the proposed rule are under development. The agency anticipates it would be many months before a final rule is in place; compliance deadlines have not yet been determined.

Historic concern

The importance of reducing worker exposure to silica dates back decades. In 1938, then secretary of labor Frances Perkins addressed the topic and the need for worker protection.

OSHA has a link to a video of Perkins’s remarks on its dedicated silica web page at http://www.OSHA.gov/silica. You’ll also find fact sheets, background information, and details about how to participate in the rulemaking process.