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Silica Rulemaking

The U.S. Department of Labor on June 30 announced a proposal by its Mine Safety and Health Administration to amend current federal standards to better protect the nation’s miners from health hazards related to exposure to respirable crystalline silica, or silica dust. The proposed rule change will ensure miners have at least the same level of protections as workers in other industries.

Unhealthy levels of silica, a carcinogen, and exposures over time cause severe illnesses, including silicosis; progressive massive fibrosis; non-malignant respiratory disease, such as emphysema; kidney disease; and lung cancer. Exposure to mixed coal mine dust that contains respirable crystalline silica can lead to the development of coal workers’ pneumoconiosis, commonly known as black lung disease; multi-dust pneumoconiosis; and progressive massive fibrosis.

The proposed rule would require mine operators to maintain miners’ Permissible Exposure Limit to respirable crystalline silica at or below 50 micrograms per cubic meter of air for a full shift exposure, calculated as an 8-hour time weighted average. If a miner’s exposure exceeds the limit, the proposed rule would require operators to take immediate corrective actions to come into compliance.

In addition to reducing the existing exposure limit, the proposal also includes other requirements to protect miners’ health — such as exposure sampling — and medical surveillance at no cost for metal and nonmetal miners. It would also replace existing outdated requirements for respiratory protection with a standard that reflects the latest advances in respiratory protection technologies and practices.

Following the proposed rule’s publication in the Federal Register, MSHA will welcome public comments and announce dates for upcoming public hearings in Arlington, Virginia, and Denver, Colorado. The hearings will be open for in-person or online participation.

Statement from the MSHA Assistant Secretary about Silica Enforcement

This document, concerning Lowering Miners’ Exposure to Respirable Crystalline Silica and Improving Respiratory Protection, is an action posted by the Mine Safety and Health Administration. Though it is not intended or expected, should there be any discrepancy between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available at solely as a means to facilitate the public’s access to this document. 

Accessibility Statement 

The Mine Safety and Health Administration (MSHA) at the U.S. Department of Labor (DOL) is commited to providing access to all individuals who are seeking information from the Agency and to complying with Section 508 of the Rehabilitation Act of 1973 as amended.     

Section 508 requires that all individuals with disabilities (whether they are federal government employees or members of the general public) have access to, and use of information and data, comparable to that provided to individuals without disabilities, unless an undue burden would be imposed on MSHA. At this point, this document is not accessible, but a fully accessible version will be posted to concurrent with the publication of the Notice of Proposed Rulemaking in the Federal Register. Any individual with a disability who has difficulty accessing documents and materials related to Lowering Miners' Exposure to Respirable Crystalline Silica and Improving Respiratory Protection proposed rule should contact MSHA, Office of Standards, Regulations, and Variances (OSRV) at (email) or 202-693-9440 (voice).     

The email should include:    

  • Nature of the accessibility problem encountered;  
  • URL (web address) of the page or pages in question;  
  • Specific information sought; and  
  • Contact email address or phone number for a response.  

OSRV staff will respond promptly and work to provide the information being sought.