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[April 30, 2007 (Volume 72, Number 82)]
[Unified Agenda]

Department of Labor (DOL)
Mine Safety and Health Administration (MSHA)
Long-Term Actions


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1816. RESPIRABLE CRYSTALLINE SILICA STANDARD

Priority: Other Significant

Legal Authority: 30 USC 811; 30 USC 813

CFR Citation: 30 CFR 56 to 57; 30 CFR 70 to 72; 30 CFR 90

Legal Deadline: None

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, which ultimately may be fatal. Both formulas are designed to limit exposures to 0.1 mg/ m3 (100mg) 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 and ACGIH recommend a 50 mg/m3 exposure limit for respirable crystalline silica. MSHA is considering several options to reduce miners' exposure to crystalline silica.

Timetable:
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Action                            Date                      FR Cite

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Request for Information          To Be                       Determined

Regulatory Flexibility Analysis Required: Undetermined

Government Levels Affected: None

URL For More Information:
www.msha.gov/regsinfo.htm www.regulations.gov

URL For Public Comments:
www.regulations.gov

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

RIN: 1219-AB36

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