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DOL/MSHA RIN: 1219-AB36 Publication ID: Fall 2009
Title: Respirable Crystalline Silica Standard
Abstract: Current standards limit exposures to quartz (crystalline silica) in respirable dust. The coal mining industry standard is based on the formula 10mg/m3 divided by the percentage of quartz where the quartz percent is greater than 5.0 percent calculated as an MRE equivalent concentration. The metal and nonmetal mining industry standard is based on the 1973 American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values formula: 10 mg/m3 divided by the percentage of quartz plus 2. Overexposure to crystalline silica can result in some miners developing silicosis, an irreversible but preventable lung disease, which ultimately may be fatal. Both formulas are designed to limit exposures to 0.1 mg/m3 (100ug) of silica. The Secretary of Labor's Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers made several recommendations related to reducing exposure to silica. NIOSH recommends a 50 ug/m3 exposure limit for respirable crystalline silica, and ACGIH recommends a 25 ug/m3 exposure limit. MSHA will publish a proposed rule to address miners' exposure to respirable crystalline silica.
Agency: Department of Labor(DOL) Priority: Other Significant
RIN Status: Previously published in the Unified Agenda Agenda Stage of Rulemaking: Proposed Rule Stage
Major: No Unfunded Mandates: No
CFR Citation: 30 CFR 56 to 57; 30 CFR 70 to 72; 30 CFR 90 (To search for a specific CFR, visit the Code of Federal Regulations.)
Legal Authority: 30 USC 811; 30 USC 813
Legal Deadline: None

Statement of Need: MSHA standards are outdated; current regulations may not protect workers from developing silicosis. Evidence indicates that miners continue to develop silicosis. MSHA's proposed regulatory action exemplifies the agency's commitment to protecting the most vulnerable populations while assuring broad-based compliance. MSHA will regulate to eliminate or reduce the hazards with the broadest and most serious consequences based on sound science. MSHA intends to use OSHA's work on the health effects and risk assessment, adapting it as necessary for the mining industry.

Summary of the Legal Basis: Promulgation of this standard is authorized by sections 101 and 103 of the Federal Mine Safety and Health Act of 1977.

Alternatives: This rulemaking would amend and improve health protection from that afforded by the existing standard. MSHA will consider alternative methods of addressing miners' exposure based on the capabilities of the sampling and analytical methods.

Anticipated Costs and Benefits: MSHA will prepare estimates of the anticipated costs and benefits associated with the proposed rule.

Risks: For over 70 years, toxicology information and epidemiological studies have shown that exposure to respirable crystalline silica presents potential health risks to miners. These potential adverse health effects include simple silicosis, progressive massive fibrosis (lung scarring). Evidence indicates that exposure to silica may cause cancer. MSHA believes that the health evidence forms a reasonable basis for reducing miners' exposure to respirable crystalline silica.

Timetable:
Action Date FR Cite
NPRM 04/00/2011
Regulatory Flexibility Analysis Required: Undetermined Government Levels Affected: Local, State
Small Entities Affected: Businesses, Governmental Jurisdictions Federalism: No
Included in the Regulatory Plan: Yes
RIN Information URL: www.msha.gov/regsinfo.htm Public Comment URL: www.regulations.gov
RIN Data Printed in the FR: No
Agency Contact:
Patricia W. Silvey
Director, Office of Standards, Regulations, and Variances
Department of Labor
Mine Safety and Health Administration
1100 Wilson Boulevard, Room 2350,
Arlington, VA 22209-3939
Phone:202 693-9440
Fax:202 693-9441
Email: silvey.patricia@dol.gov