After Considering Comments, OR-OSHA Changes Silica PEL
Oregon OSHA recently adopted final changes to the permissible exposure limit for airborne concentrations of respirable silica to a fixed limit of 0.1 milligrams per cubic meter (mg/m3). The formula and footnote (e) for Silica in Table Z-3 in the Air Contaminants standards in general industry and construction is also amended. Both of these changes reflect better scientific processes for determining airborne contaminants exposures, the agency says. Comments received during the comment period and during the public hearing indicated that the proposed change of 0.05 mg/m3 would impact industry more than OR-OSHA had anticipated.
The original calculation was based on a 0.1 mg/m3 limit. OR-OSHA said it carefully considered the comments it received and as a result is adopting a PEL of 0.1 mg/m3, effective July 1 as OR-OSHA Administrative Order 6-2008 for general industry and construction. The agency also received comments regarding the proposed sampling method and as a result is adopting a rule that allows for a sampling method accepted by OSHA or NIOSH for respirable quartz silica.
Crystalline silica, also known as quartz, is a natural constituent of the earth's crust and is a basic component of sand and granite. However, airborne exposures to silica can lead to silicosis. Silicosis is a disease of the lungs that can cause fibrosis or scar tissue formations in the lungs that reduce the lung's ability to work to extract oxygen from the air. For all proposed, adopted, and final rules, as well as current publications, training opportunities, and more, visit OR-OSHA's Web site, www.orosha.org.