OSHA Proposes Lower Rate Requirements of Exposure to Crystalline Silica



In late August, the Occupational Safety and Health Administration (OSHA) issued a proposed rule to lower worker exposure to crystalline silica. According to a news release issued by the agency, the dust is a cause of silicosis, an incurable and progressive disease-lung cancer, chronic obstructive pulmonary disease and kidney disease that kills hundreds of workers and sickens thousands more each year.


Exposure to airborne silica dust occurs in operations involving cutting, sawing, drilling and crushing of concrete, brick, block and other stone products and in operations using sand products, such as in glass manufacturing, foundries and sand blasting. OSHA expects that limiting the exposure to this dust could save nearly 700 lives per year and prevent 1,600 new cases of silicosis annually.


The proposed rulemaking includes two separate standards, one for general industry and maritime employment, and one for construction. These standards are based on review of scientific and technical evidence, consideration of current industry consensus standards, and outreach by OSHA to stakeholders, including public stakeholder meetings, conferences, and meetings with employer and employee organizations.


The current standards are more than 40 years old, and they are based on research from the 1960's and even earlier. Since OSHA issued its current silica standards in 1971, numerous studies have found increased risk of lung cancer among silica-exposed workers. The U.S. National Toxicology Program, the International Agency for Research on Cancer and the National Institute for Occupational Safety and Health have all identified respirable silica as a human carcinogen, a cause of lung cancer in workers exposed to the dust.


OSHA currently is inviting the submission of written comments prior to its public hearings that are scheduled to begin in Washington, D.C., in early March. Among the feedback the organization has received thus far is one response from the Crystalline Silica Panel of the American Chemistry Council, which issued the following statement in response to the OSHA proposal: “The best available science, to our understanding, shows that the current OSHA PEL for quartz of 0.1 mg/m3 is appropriate to protect against silica-related disease, provided it is adhered to strictly. Accordingly, achieving full compliance with, and enforcement of, the current PEL is the best way to protect silica-exposed workers.”


The panel points to data from the U.S. Centers for Disease Control that shows a greater than 90 percent reduction in the silicosis mortality rate from 1968 to 2010 as evidence that current standards are appropriate. According to this organization, non-compliance with existing standards is the cause of the continued fatalities as a result of silicosis.


For more information, visit www.osha.gov/silica.