and Health Administration (OSHA) of a proposed lower standard for crystalline silica exposure.
“This needed adjustment is long overdue,” said Tee L. Guidotti, MD, MPH, chair of the Department of
Environmental and Occupational Health at the School of Public Health and Health Services of the George
Washington University Medical Center in Washington DC and a member of the American Thoracic
Society’s Environmental Health Policy Committee involved in the Society’s efforts to establish a lower
exposure standard. “The current OSHA standard of for respirable crystalline silica of 0.10 mg/m3 8 hour
time weighted average has remained the same for 40 years and has been shown in numerous studies not to be
“We support the proposed lower standard of 0.05 mg/m3 time-weighted average for up to 10 hours during a
40 hour work week, which will protect hundreds and possibly thousands of workers from silica-related
health effects at almost no cost, as silica exposure can be easily prevented with simple and inexpensive
Crystalline silica has long been recognized as a serious occupational health hazard, affecting workers in
industries such as granite workers, industrial sand workers and gold miners. Overexposure to respirable
crystalline silica can cause irreversible, progressive lung disease, known as silicosis, and is also associated
with lung cancer, chronic renal disease, and autoimmune disorders. It is estimated that 1.7 million U.S.
workers are regularly exposed to this serious health hazard and that about 200 workers die each year from
silicosis. As many as 7,300 new cases of silicosis occur annually among U.S. workers.
Exposure levels and death rates from silica-related diseases in the U.S. far exceed those of comparable
developed economies around the world. Silicosis has been virtually eliminated in the European Union with
the use of simple and inexpensive measures such as adequate ventilation, wetting rock before it is cut, and
banning sandblasting with silica sand in favor of readily available alternatives.
OSHA first submitted a draft revised standard on respirable crystalline silica to the Office of Management
and Budget’s Office of Information and Regulatory Affairs on February 14, 2011, but a review was not
completed until recently.
“The proposed revised standard should be implemented in conjunction with a mandated periodic surveillance
program to ensure that the measures taken to control exposure are adequate and to identify and mitigate
disease in those workers who are exposed,” said Dr. Guidotti. “Silicosis and the other diseases caused by
crystalline silica exposure are entirely preventable and this new lower standard is an important step toward