OSHA's 2013 "Deadly Dust" video about silicaOSHA's Notice of Proposed Rulemaking (NPRM) for Occupational Exposure to Respirable Crystalline Silica has been submitted for publication in the Federal Register. The NPRM is OSHA's formal notice of regulatory action related to Occupational Exposure to Crystalline Silica. This is a proposal, not a final rule.

The proposed rulemaking would reduce the amount of silica exposure allowed in general industry and the maritime industry by 50 percent. The exposure limit in the construction industry would be cut by 80 percent.

Workers’ exposures would be limited to a new PEL of 50 micrograms of respirable crystalline silica per cubic meter of air (50 µg/m3), averaged over an 8-hour day.

The current permissible exposure limits (PELs) for crystalline silica were established 40 years ago and are “outdated, inconsistent between industries, and do not adequately protect worker health,” according to OSHA, which says the proposed rule “brings protections into the 21st century.”

There are an estimated 2.2 million workers in the U.S. are exposed to silica dust. OSHA expects the proposed rule to save nearly 700 lives and prevent 1,600 new cases of silicosis per year, once the full effects of the rule are realized.


The rulemaking process includes comments and hearings.

Written comments can be submitted within 90 days after the NPRM is published in the Federal Register. Comments can be submitted by:

  • Visiting the Federal e-Rulemaking Portal at www.regulations.gov, Docket ID# OSHA-2010-0034. (Note: The docket will open for comments when the NPRM is published in the Federal Register.)
  • Faxing OSHA's Docket Office at 202-693-1648 (for comments of 10 pages or less).
  • Sending hard-copy documents (via regular mail, express delivery, courier, or hand delivery) to the OSHA Docket Office, Technical Data Center, Room N-2625, OSHA, U.S. Department of Labor, 200 Constitution Ave., NW., Washington, D.C. 20210.


Public hearings on the proposed rule are scheduled to begin on March 4, 2014 at the Department of Labor's Frances Perkins Building in Washington, D.C.

If you want to attend and listen to testimony from other stakeholders, there is no need to notify OSHA.

If you would like to testify or question witnesses at the Washington, D.C. hearings, you must file a written notice of intention to appear within 60 days following publication of the NPRM in the Federal Register. Visit www.regulations.gov for additional information and to file your notice after the NPRM is published in the Federal Register.

Providing comments after public hearings

Following the public hearings, members of the public who filed a timely written notice of intention to appear prior to the hearings can submit post-hearing comments and briefs to the docket. The duration of the periods for submitting post-hearing comments and briefs will be set at the conclusion of the hearings. OSHA also publishes a transcript of the hearings and makes it available to the public in the rulemaking docket.

Click here for details about OSHA’s crystalline silica rulemaking.

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