OSHA Publishes Silica Proposed Rule
This triggers the 90-day countdown to the deadline for filing comments on a proposal that is the most important regulatory action by OSHA this year, so far.
OSHA's proposed rule to reduce the PEL for workers' exposure to respirable crystalline silica in general industry, construction, and shipyards is published in the Sept. 12 Federal Register. Publication of the 755-page rule – thus far, the most important regulatory action by OSHA this year – starts the 90-day countdown to the deadline for submitting comments. Dec. 11 is the deadline.
The proposed PEL of 50 micrograms per cubic meter of air as an eight-hour time weighted average is half of the current PEL for quartz, the most common form of crystalline silica, in general industry and far below the now-obsolete PELs for crystalline silica applied to construction and shipyards; it would be approximately equivalent to 250 μg/m3, according to the proposed rule and to Assistant Secretary Dr. David Michaels, who announced the proposed rule Aug. 23 in a news conference.
OSHA has defined the action level for the proposed standard as an airborne concentration of respirable crystalline silica of 25 μg/m3 calculated as an eight-hour TWA, as is typical in its other standards: The action level, which triggers exposure monitoring, has been set at half of the PEL.
OSHA is proposing other elements of a comprehensive health standard, including requirements for exposure assessment, preferred exposure control methods, respiratory protection, medical surveillance, hazard communication, and recordkeeping.
The rule explains that OSHA "preliminarily determined" an even lower PEL – 25 micrograms per cubic meter of air, 8-hr TWA – would not be feasible because engineering controls and work practices could not reduce silica exposures that low at most sites in the affected industries.
To file a comment electronically, visit www.regulations.gov and search for Docket No. OSHA 2010-0034. The full text of the rule is available here.
In the document, OSHA confirms it will hold informal public hearings beginning March 4 in Washington, D.C., and they may last several days. Peer reviewers of OSHA’s Health Effects Literature Review and Preliminary Quantitative Risk Assessment will be present to hear testimony on the second day, March 5.