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[April 24, 2006 (Volume 71, Number 78)]
[Unified Agenda]
[Page 22925]

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


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1969. RESPIRABLE CRYSTALLINE SILICA STANDARD

Priority: Other Significant

Legal Authority: 30 USC 811; 30 USC 813

CFR Citation: 30 CFR 56; 30 CFR 57; 30 CFR 58; 30 CFR 70; 30 CFR 71; 30 CFR 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 may ultimately be fatal. Both formulas are designed to maintain exposures to 0.1 mg/m3 (100 ug) 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 50ug/ 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

Agency Contact: Patricia W. Silvey, Acting Director, Office of
Standards, Regulations, and Variances, Department of Labor, Mine Safety
and Health Administration, 1100 Wilson Boulevard, Room 2349, Arlington,
VA 22209-3939
Phone: 202 693-9440
Fax: 202 693-9441
Email: silvey.patricia@dol.gov

RIN: 1219-AB36

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