New Rules Would Cut Silica Dust Exposure for Workers

In a move aimed at protecting workers in several industries against lung cancer and other deadly diseases, the Occupational Safety and Hazard Administration issued a proposed rule Friday that would dramatically limit permissible levels of crystalline silica, a known carcinogen.

A basic component of soil, sand, granite and other naturally-occurring resources, silica becomes airborne during the sawing, drilling and crushing of concrete, brick and other stone products as well as in operations using sand products, such as glass manufacturing and sand blasting.

Among the effects of inhaling silica dust is silicosis, a chronic respiratory disease that makes it difficult for a person to breathe. Chronic obstructive pulmonary disease and kidney disease are also linked to exposure to silica dust.

According to Dr. David Michaels, assistant secretary of labor in charge of OSHA, crystalline silica kills hundreds or workers and sickens thousands more every year. In all, the agency estimates that the proposed rule would save some 700 lives per year and prevent a total of 1,600 new cases of silicosis annually.

Current standards, set back in 1971, Michaels explains, are based on research reaching as far back as the 1960s and earlier and, as a result, are not reflective of latest scientific research on the substance and its effects. For example, since the last set of standards were set over 40 years ago, the US National Toxicology Program, the International Agency for Research on Cancer and the National Institute for Occupational Safety and Health have all identified silica as a human carcinogen.

"This proposal," he said in statement, "is long overdue."

Methods of reducing exposure to silica include using a vacuum to collect dust at the point where it is created and thus before workers can inhale it or keeping the material wet to prevent it from becoming airborne in the first place.

The agency will be accepting written comment on the proposed rules over the next 90 days before proceeding with public hearings.