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[December 11, 2006 (Volume 71, Number 237)]
[Unified Agenda]
[Page 73561]

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


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2115. RESPIRABLE CRYSTALLINE SILICA STANDARD

Priority: Other Significant

Legal Authority: 30 USC 811; 30 USC 813

CFR Citation: 30 CFR 56 to 58; 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 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, 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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