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[December 11, 2006 (Volume 71, Number 237)]
[Unified Agenda]
[Page 73562-73563]

Department of Labor (DOL)
Mine Safety and Health Administration (MSHA)
Completed Actions



Priority: Other Significant

Legal Authority: 30 USC 811; 30 USC 813

CFR Citation: 30 CFR 57

Legal Deadline: None

Abstract: On January 19, 2001 MSHA published a final rule addressing diesel particulate matter (DPM) exposure of underground metal and nonmetal miners (66 FR 5706). The final rule established new health standards for underground metal and nonmetal mines that use equipment powered by diesel engines. The rule established an interim concentration limit of 400 micrograms of total carbon per cubic meter of air that became applicable July 20, 2002, and a final concentration limit of 160 micrograms to become applicable after January 19, 2006. Industry challenged the rule and organized labor intervened in the litigation. Settlement negotiations with the litigants have resulted in further regulatory actions on several requirements of the rule. One final rule was published on February 27, 2002, (67 FR 9180). MSHA issued an advance notice of proposed rulemaking (ANPRM) on September 25, 2002, (67 FR 60199) to obtain additional information and published a notice of proposed rulemaking (NPRM) in August 2003 (68 FR 48668). MSHA issued a final rule on June 6, 2005 (70 FR 32868) that revised MSHA's existing standards addressing diesel particulate matter (DPM) exposure in underground metal and nonmetal (M/NM) mines. The rule, among other things, changed the interim concentration limit measured by total carbon (TC) to a comparable permissible exposure limit (PEL) measured by elemental carbon (EC). MSHA proposed a rule (70 FR 53280) on September 7, 2005, to phase in the final DPM limit because the agency was concerned that there may be feasibility issues for some mines to meet the final limit of 160 micrograms by January 20, 2006. Accordingly, MSHA proposed a five-year phase-in period and noted our intent to initiate a separate rulemaking to convert the final DPM limit from a total carbon limit to an elemental carbon limit. We also proposed to delete the existing provision that restricts newer mines from applying for an extension of time for meeting the final concentration limit. In addition, we requested comments and data on an appropriate conversion factor for the final DPM limit, technological implementation issues, and the costs and benefits of the proposed rule. We also requested comments on the appropriateness of including in a final rule a provision for medical evaluation of miners required to wear respiratory protection and transfer of miners who have been determined by a medical professional to be unable to wear a respirator. Public hearings were held in January 2006.

On May 18, 2006 (71 FR 28924), MSHA published a final rule that phases in the DPM final limit of 160TC ug/m3 over a two-year period, based on feasibility. On May 20, 2006, the first phase of the final limit of 308 EC ug/m3 became effective. On January 20, 2007, the DPM final limit will be reduced to 350TC ug/m3. The final limit of 160TC ug/m3 will become effective on May 20, 2008. Mine operators must continue to use engineering and administrative controls, supplemented by respiratory protection when needed, to reduce miners' exposures to the prescribed limits. As with the interim DPM limit, MSHA will enforce the final limits as permissible exposure limits (PEL).

The final rule also establishes new requirements for medical evaluation of miners required to wear respiratory protection, and transfer of miners who are medically unable to wear a respirator. It deletes the existing provision that restricts newer mines from applying for an extension of time in which to meet the final limit.

MSHA is committed to initiating a separate rulemaking to determine the correct TC to EC conversion factor for the phased-in final limits.


Action                            Date                      FR Cite


Final Action                    02/27/02                     67 FR 9180
ANPRM                           09/25/02                    67 FR 60199
ANPRM Comment Period End        11/25/02
NPRM                            08/14/03                    68 FR 48668
NPRM Comment Period End         10/14/03
Limited Reopening of the Comment 
Period                          02/20/04                     69 FR 7881
Limited Reopening of the Comment 
Period End                      04/05/04                     69 FR 7881
Final Action                    06/06/05                    70 FR 32868
Final Action Effective          07/06/05
Second NPRM                     09/07/05                    70 FR 53280
Notice of Public Hearing        09/07/05                    70 FR 53280
Close of Comment Period         09/07/05                    70 FR 53280
Request for Data                09/07/05                    70 FR 53280
Comment Period Extended         09/19/05                    70 FR 55018
Change of Public Hearings Dates 09/19/05                    70 FR 55018
Extension Of Comment Period     01/26/06                     71 FR 4331
NPRM Comment Period End         02/17/06
Final Action                    05/18/06                    71 FR 28924
Final Action Effective          05/18/06
Final rule; corrections         06/27/06                    71 FR 36483

Regulatory Flexibility Analysis Required: No

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


RIN: 1219-AB29