# Verification of Underground Coal Mine Operators' Dust Control Plans and Compliance Sampling for Respirable Dust > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A03-3941 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** March 6, 2003 - **Citation:** 68 FR 10784 ## Text DEPARTMENT OF LABOR Mine Safety and Health Administration 30 CFR Parts 70, 75 and 90 RIN 1219-AB14 Verification of Underground Coal Mine Operators' Dust Control Plans and Compliance Sampling for Respirable Dust AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Proposed rule; notice of public hearings; close of record. SUMMARY: This proposed rule supercedes the proposed rule published by MSHA on July 7, 2000. Under this proposed rule mine operators would be required to verify and periodically monitor, through sampling, the effectiveness of the dust control parameters for each mechanized mining unit (MMU) specified in the mine ventilation plan. For samples to be valid, the operator would be required to sample on a production shift during which the amount of material produced by a MMU is at or above the verification production level using only the dust control parameters listed in the ventilation plan. The use of approved powered, air-purifying respirators (PAPRs) and/or verifiable administrative controls would be allowed as a supplemental means of compliance when MSHA determines that all feasible engineering or environmental controls are being used. MSHA is also proposing to rescind operator compliance sampling in underground coal mines. The use of a personal, continuous dust monitor (PCDM), once developed and approved, could be used by an operator in conjunction with the dust control parameters specified in the mine ventilation plan. The proposed rule would significantly improve miners health protection by limiting the exposure of individual miners to respirable coal mine dust. DATES: Comments on the proposed rule should be submitted on or before June 4, 2003. MSHA also is announcing that the Agency will hold public hearings on the proposed rule. The hearing dates and times will be announced by a separate document in the Federal Register . ADDRESSES: Comments must be clearly identified as such and transmitted either electronically to comments@msha.gov, by facsimile to (202) 693-9441, or by regular mail or hand delivery to MSHA, Office of Standards, Regulations, and Variances, 1100 Wilson Blvd., Room 2313, Arlington, Virginia 22209-3939. You may contact MSHA with any format questions. Comments are posted for public viewing at http://www.msha.gov/currentcomments.htm. Information Collection Requirements Send written comments on the information collection requirements to both the Office of Management and Budget (OMB) and MSHA as follows: (1) To OMB: If under 10 pages, by facsimile (202) 395-6974 to Attn: Desk Officer for MSHA; or by email to: cathomas@omb.gov. All comments may be sent by mail addressed to the Office of Information and Regulatory Affairs, Office of Management and Budget, New Executive Office Building, 725 17th Street, NW., Washington, DC 20503, Attn: Desk Officer for MSHA; and (2) To MSHA: Comments must be clearly identified as comments on the information collection requirements and transmitted either electronically to comments@msha.gov, by facsimile to (202) 693-9441, or by regular mail or hand delivery to MSHA, Office of Standards, Regulations, and Variances, 1100 Wilson Blvd., Room 2313, Arlington, Virginia 22209-3939. FOR FURTHER INFORMATION CONTACT: Marvin W. Nichols, Jr., Director, Office of Standards, Regulations and Variances, MSHA; phone: (202) 693-9440; facsimile: (202) 693-9441; E-mail: nichols-marvin@msha.gov. This proposed rule is also available on MSHA's webpage at http://www.msha.gov, under Statutory and Regulatory Information; Federal Register Documents; Proposed Rules. You can view comments filed on this rulemaking at http://www.msha.gov/currentcomments.htm. SUPPLEMENTARY INFORMATION: I. Table of Contents II. Background A. Procedural History B. Overview of Proposed Rule 1. New Proposed Respirable Dust Sampling Program 2. Verification of Ventilation Plan Effectiveness 3. Measures to Supplement Engineering Controls to Reduce Exposures C. Control of Coal Mine Respirable Dust D. Coal Mine Respirable Dust Task Group E. NIOSH Criteria Document F. Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers III. General Discussion A. Proposed Reforms to the Respirable Dust Monitoring Program a. Compliance Sampling b. Abatement Sampling c. Operator Verification Sampling and Quarterly Sampling d. Advantages of MSHA Sampling Over the Existing Program B. Procedures for Setting the Applicable Dust Standard When Quartz is Present 1. Proposed Procedures 2. Validity of Averaging Percentages C. Respirable Dust Control Program for Underground Coal Mines 1. Proposed Procedures for Evaluating, Approving, and Monitoring Plan Requirements D. Hierarchy of Dust Controls 1. Primacy of Engineering Controls 2. Administrative Controls 3. Limitations of Engineering Controls 4. Respiratory Protection a. Selection of Respirators: Powered Air-Purifying Respirators (PAPR) b. PAPR Protection Program c. PAPR Protection Factor E. Guidelines for Determining What is a Feasible Dust Control F. Application of New Technology for Monitoring Coal Mine Dust Levels IV. Section-by-Section Discussion of Proposed Rule A. Part 70 B. Part 75 C. Part 90 V. Health Effects A. Introduction B. Hazard Identification 1. Agent: Coal 2. Physical State: Coal Mine Dust 3. Biological Action: Respirable Coal Mine Dust C. Health Effects of Respirable Coal Mine Dust 1. Description of Major Health Effects a. Simple Coal Workers' Pneumoconiosis (Simple CWP) and Progressive Massive Fibrosis (PMF) b. Other Health Effects 2. Toxicological Literature 3. Epidemiological Literature a. Simple Coal Workers' Pneumoconiosis (Simple CWP) and Progressive Massive Fibrosis (PMF) b. Other Health Effects VI. Quantitative Risk Assessment VII. Significance of Risk VIII. Feasibility Issues A. Technological Feasibility B. Economic Feasibility IX. Preliminary Regulatory Economic Analysis A. Costs and Benefits: Executive Order 12866 1. Compliance Costs 2. Benefits B. Regulatory Flexibility Certification and Regulatory Flexibility Analysis X. Other Statutory Requirements A. Unfunded Mandates Reform Act of 1995 B. Paperwork Reduction Act of 1995 C. National Environmental Policy Act D. Executive Order 12630: Governmental Actions and Interference with Constitutionally Protected Property Rights E. Executive Order 12988: Civil Justice Reform F. Executive Order 13045: Protection of Children from Environmental Health Risks and Safety Risks G. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments H. Executive Order 13132: Federalism I. Executive Order 13211: Energy J. Executive Order 13272: Proper Consideration of Small Entities in Agency Rulemaking XI. Public Hearings Appendix A. Derivation of the Critical Values Appendix B. Model Powered Air-Purifying Respirator (PAPR) Program Appendix C. Citation Threshold Values (CTV) Appendix D. References Appendix E. Supplemental References XII. Regulatory Text II. Background A. Procedural History On July 7, 2000, the Mine Safety and Health Administration published a Notice of Proposed Rulemaking (NPRM) in the Federal Register: Verification of Underground Coal Mine Operators' Dust Control Plans and Compliance Sampling for Respirable Dust (65 FR 42122). A notice of public hearing and close of record was also published in the Federal Register (65 FR 42186) on July 7, 2000. During August 2000, three public hearings were conducted in Morgantown, West Virginia; Prestonsburg, Kentucky; and Salt Lake City, Utah. Transcripts of those proceedings were made available to the public. The close of the rulemaking record was originally scheduled for August 24, 2000. In response to requests from commenters, an extension of the comment period for the NPRM was published in the Federal Register (65 FR 49215) on August 11, 2000; the rulemaking comment period was extended to September 8, 2000. Supplementary statements and data postmarked on or before the close of the record, September 8, 2000, were included in the rulemaking record and made available to the public. Many commenters on the proposed rule urged MSHA to withdraw the proposed rule and publish another. In their opinion, the agency failed to adequately address the concerns of mine operators and ignored other reforms in the dust sampling program urged by coal miners since the mid 1970s or that were recommended by the Secretary of Labor's Advisory Committee on the Elimination of Pneumoconiosis Among Coal Workers (Dust Advisory Committee) and the NIOSH Criteria Document addressing respirable coal mine dust. After carefully considering all the facts, issues, and concerns raised by commenters during this rulemaking, MSHA concluded that, to proceed to a final rule would not be in the best interest of miners' health or the mining community. The Agency is re-proposing for further public comment, the rule which is the subject of this rulemaking. B. Overview of Proposed Rule In preparing this proposed rule, MSHA has responded to comments that were made to the July 7, 2000 proposed rule. However, since this proposed rule differs from the earlier proposed rule in several areas, the agency may not have addressed each concern that was identified by the earlier commenters. MSHA believes that the proposed rule would significantly improve miners' health protection from the debilitating effects of occupational respiratory disease by limiting their exposures to respirable coal mine dust to no more than the applicable dust standard on each shift. 1 Accordingly, this proposed rule revises 30 CFR part 70, subparts A, B, and C; amends two existing sections of part 75; and revises part 90, subparts A, B, C, and D. 1 For details, see the Quantitative Risk Assessment and Significance of Risk Sections. Under this proposed rule, MSHA would be responsible for all compliance and abatement sampling, which is currently being carried out by the operator. This includes frequent sampling of each mechanized mining unit (MMU) and part 90 miner, sampling of outby Designated Areas (DAs) and occupations, and abatement sampling. This proposed rule specifies that compliance and abatement determinations will be based on the results of single samples. Also, only MSHA samples would be used to set a reduced dust standard when the quartz content of the respirable dust exceeds five percent. In response to comments raised in the earlier proposed rule, mine operators will continue to play a role in monitoring the mine environment. The proposed rule requires each underground operator to verify, through sampling, that the dust control parameters specified in a mine ventilation plan are effective in controlling the concentration of respirable coal mine dust and quartz dust at or below the verification limits of 2.0 mg/m 3 and 100 μg/m 3 respectively. For a sample to be valid for verification purposes, the amount of material produced must be at or above the “verification production level” or VPL. The VPL is defined as the tenth highest production level recorded in the most recent 30 production shifts. In addition, the engineering or environmental control parameters must not exceed 115% of the quantities specified in the ventilation plan and the sampling must take place over the entire production shift. The dust control parameters specified in mine ventilation plans must be designed to maintain dust concentrations at or below the applicable standard on each shift. If during the initial verification sampling, the VPL is achieved and dust concentrations are sufficiently low, the district manager could approve a plan based on one shift of sampling. However, if dust concentration measurements are higher, or if the actual production was less than the VPL, MSHA will require the operator to sample additional shifts. All verification samples would be submitted to MSHA for analysis. However, mine operators would not be cited if sample results show an overexposure so long as the operator takes steps to identify and correct the condition that caused the verification limit to be exceeded. Also, to confirm the continued effectiveness of the plan parameters, mine operators would be required to sample quarterly each producing MMU designated by MSHA under the same conditions that were in place when the plan parameters were initially verified. As in the earlier proposed rule, mine operators would be required to maintain records of the total amount of material produced by shift for each MMU. In the earlier proposed rule, commenters expressed concern about a provision in the July 7, 2000 proposed rule allowing the use of supplementary controls (powered, air-purifying respirators (PAPRs) and administrative controls), on an interim basis, in mines utilizing longwall mining technology. Commenters offered a wide range of opinions on this part of the proposed rule. Some commenters supported MSHA's decision to allow the use of supplementary controls, but criticized the proposed rule for being too restrictive. Other commenters objected to the proposed provision, claiming that the requirement was inconsistent with the provision of the Mine Act which prohibits respirators to be used as substitutes for engineering controls. These commenters were also concerned that operators would have no incentive to implement available engineering controls once they are permitted to use supplementary controls as proposed. This proposed rule recognizes that there may be circumstances where, even after implementing all feasible engineering or environmental controls, a mine operator may be unable to maintain concentrations at or below the verification limits. This includes operations that employ longwalls or other mining systems. In those instances, the proposed rule would allow a mine operator, with the approval of the Administrator of Coal Mine Safety and Health, to use either PAPRs or administrative controls or a combination of both to supplement engineering or environmental controls to reduce the dust exposure of individual miners. Approval to use supplementary control measures would be contingent on the mine operator adopting new engineering and environmental controls when they become available. The proposed rule also recognizes that there may be special situations that occur intermittently and for short periods of time where the approved dust control measures may not protect miners from overexposure. An example would be where the operator is required to mine through a rock parting with high quartz content. In these situations, the district manager may allow the operator to use PAPRs for a period not to exceed 30 calendar days. This proposed rule would require that the mine operator provide a copy of any request for supplemental controls to the representative of the miners. This would provide an opportunity for miners' input prior to MSHA making any determination. A full discussion of these and other provisions is provided in the section-by-section analysis of this proposed rule. A number of commenters stated that MSHA's earlier proposed rule was incomplete because it did not address some key recommendations of by the Dust Advisory Committee, and by NIOSH in its Criteria Document (see sections II.E. and II.F. of the preamble). Some of these commenters expressed concern that the proposed rule failed to recognize and consider alternatives involving continuous dust monitoring technology. Since publication of that earlier proposed rule, technology has advanced to a point that will likely allow for continuous monitoring of dust exposures in the near future. Accordingly, this proposed rule has provisions that would allow mine operators to adopt such technology to meet the requirements for operator monitoring of dust control effectiveness and miner exposure. The recommendations regarding exposure limits for respirable coal mine dust and crystalline silica were beyond the scope of either the single sample or plan verification rules. In the interim, MSHA enforcement efforts continue to focus on lowering the quartz exposure of miners as recommended by the Dust Advisory Committee. 1. New Proposed Respirable Dust Sampling Program In order to improve miner confidence in the respirable dust sampling program, the proposed rule revises the existing operator sampling requirements for underground mines and for part 90 miners under 30 CFR parts 70 and 90, respectively, and provides that MSHA conduct compliance and abatement sampling. This proposed rule would result in fewer shifts being sampled than under existing requirements. However, MSHA believes that the amount of sampling it will conduct under the proposed rule will be more protective because a greater number of individual compliance determinations would be made. MSHA samples the Designated Occupation (DO) and at least four other occupations, if available, on each sampling inspection. Also, since all MSHA sampling is unannounced, sampling will occur under conditions that are more typical of the actual mining environment. In addition, compliance determinations would be based solely on a single-sample measurement and not on an average of multiple shift measurements. Multiple shift measurements can mask overexposures by diluting a measurement of high dust exposure with lower measurements made on different shifts or at different occupational locations. Commenters to the July 7, 2000 proposed rule also criticized MSHA for failing to fully incorporate the preamble discussion on the Agency's sampling procedures into the proposed regulation to prevent those procedures from being changed or modified in the future. MSHA does not believe that it would be appropriate to incorporate agency enforcement procedures into rules that are designed to regulate the mining industry. It is necessary for MSHA to retain the ability to modify its enforcement policies and procedures in response to, among other things, case law, new health or safety concerns, major mine emergencies, or changes in technology which may require the agency to redirect its efforts to protect miner health and safety. In order to provide the mining community with an understanding of how the agency intends to enforce this proposed rule, MSHA has published a draft of Chapter 1 (Respirable Dust) of MSHA's health inspection procedures (see http://www.msha.gov ) which it intends to adopt as its enforcement strategy when the final rule becomes effective. 2. Verification of Ventilation Plan Effectiveness The proposed rule requires that each underground coal mine operator must have a mine ventilation plan verified by operator sampling. The verified plan must be effective in controlling respirable dust in each MMU under typical mining conditions prior to approval of the plan by the district manager. In addition, mine operators would be required to sample quarterly each producing MMU designated by MSHA to determine if the dust control measures specified in the approved ventilation plan, continue to protect miners from overexposure. No citations would be issued to mine operators based on the results of this sampling as long as the operator takes steps to eliminate the conditions which caused any overexposure identified through such sampling. Consistent with the Mine Act and its implementing regulations, this proposed rule preserves the primacy of engineering controls to the extent that they are technologically and economically feasible. The dust control parameters specified in the mine ventilation plans should be designed to control respirable dust and prevent overexposures on individual shifts. These plans should accurately reflect the engineering or environmental controls that are suitable to the mining system and operating conditions at the MMU. Under the proposed rule, the mine operator will collect respirable dust samples to demonstrate the adequacy of the dust control parameters specified in the mine ventilation plan in maintaining the concentration of respirable coal mine and quartz dust at or below the “verification limits” of 2.0 mg/m 3 and 100 μg/m 3 , respectively. The adequacy of the dust control parameters must be demonstrated on shifts during which the amount of material produced is at or above the “verification production level” (VPL) or the tenth highest production level recorded in the most recent 30 production shifts, and using only the engineering or environmental control parameters proposed in the ventilation plan, at levels not exceeding 115 percent of the quantities specified in the plan. The proposed rule would require mine operators to: (a) Set and maintain the dust control parameters during verification sampling at levels specified in the plan; (b) maintain and make available to MSHA records of the amount of material produced by each mechanized mining unit during each production shift; (c) provide additional information in mine ventilation plans such as the VPL, shift length, etc.; and (d) provide the miners' representative the opportunity to participate in the plan verification process. During sampling to secure plan approval, the district manager could approve a plan based on one shift of sampling if the VPL is achieved, and respirable dust concentrations are sufficiently low. However, if dust concentration measurements are higher, or if the actual production was less than the VPL, the mine operator would be required to sample additional shifts. 3. Measures To Supplement Engineering Controls to Reduce Exposures Under the proposed rule, if a ventilation plan cannot be verified using all feasible engineering or environmental controls, the mine operator may be permitted to use either powered, air-purifying respirators (PAPRs) or verifiable administrative controls, or a combination of both, as a supplemental means of control (see section III.D. Hierarchy of Dust Controls). MSHA may, under certain conditions, approve such use only after the Administrator for Coal Mine Safety and Health has determined that all feasible engineering or environmental controls have been adopted in the ventilation plan, but miners continue to be at risk of overexposure. District managers may also approve the use of supplementary controls for limited periods of time when unusual or intermittent adverse conditions could result in miners not being fully protected by the approved dust control plan. These and other provisions of the proposed rule are explained in more detail in the Section-by-Section Discussion of this preamble. C. Control of Coal Mine Respirable Dust Maintaining a work environment free of excessive levels of respirable coal mine dust and quartz dust (hereafter referred to as “respirable dust”) is essential for long-term health protection. Section 202(b)(2) of the Federal Mine Safety and Health Act of 1977 (Mine Act) requires each operator to continuously maintain the average concentration of respirable dust in the mine atmosphere, during each shift to which each miner in the active workings of such mine is exposed, at or below 2.0 milligrams of respirable dust per cubic meter of air (mg/m 3 ). Under the Mine Act and the implementing regulations, when respirable coal mine dust contains more than five percent quartz, the applicable dust standard is further reduced by means of a formula. Although MSHA does not enforce a separate standard for respirable quartz dust, the formula (10 divided by the percentage quartz) used to establish an applicable dust standard, in effect, limits respirable quartz concentrations to 100 μg/m 3 (as an MRE equivalent). Consistent with the Mine Act and MSHA regulations, the primary focus of the federal respirable dust program is on controlling the concentrations of respirable dust in the environment where miners work or travel through the application of feasible engineering or environmental control measures. Engineering or environmental controls for respirable dust in the mine environment are the proven dust-control techniques and the principal methods for protecting miners' health. These include all methods for controlling the quantity of respirable dust in the air that a miner breathes by either reducing dust generation, or by suppressing, diluting, capturing, or diverting the dust that is being generated by the mining process. Under the Mine Act, the mine operator has primary responsibility for implementing a program to control respirable dust so that all miners work in an environment free of excessive levels of respirable dust. Mine operators must develop, implement, and maintain effective measures to control the level of respirable dust in the mine environment, and evaluate these control measures at regular intervals to ensure that they function as intended. These control measures, or “dust control parameters,” are required to be specified in the dust control portion of the operator's mine ventilation plan under § 75.370. Mine ventilation plans are a long-recognized means of addressing health issues that are mine-specific and for achieving work environments that are free of excessive concentrations of respirable dust. Currently, section 75.370 requires each operator of an underground coal mine to develop and follow a ventilation plan that is designed to control methane and respirable dust in the mine. The plan must be suitable to the conditions and mining systems employed at the mine. Although ventilation plans must be designed to control respirable dust, there has been no requirement that the plan's effectiveness be verified. The dust control portion of the mine ventilation plan is a key element of the operator's strategy to control respirable dust in the working environment of each mechanized mining unit (MMU) during each shift. Existing section 70.2 defines, in part, a MMU to mean “a unit of mining equipment, including hand loading equipment, used for the production of material.” The plan provides a description of the specific engineering control measures in use. The plan also contains procedures for maintenance of specific dust control equipment, such as scrubbers, dust collectors on roof bolters, and spray nozzles, or for the replacement of cutting picks to minimize dust generation. Once approved by the district manager, the dust control parameters must be employed on a continuous basis to provide protection from the hazards of respirable dust to coal miners. By insuring that the parameters are being maintained on each production shift, miners can be assured that respirable dust levels are being adequately controlled without the need to continuously monitor respirable dust levels in the mine environment. Implementing dust control parameters that have been determined effective under typical mining conditions, and maintaining these controls in proper working order, provides reasonable assurance that no miner will be overexposed. Because technology that continuously monitors respirable dust and displays dust concentrations in real-time is not yet available for use in underground coal mines, the implementation of effective ventilation plans is the only practical means of reasonably ensuring, on a continuous basis, that miners are not overexposed. In 1996, MSHA implemented revised ventilation standards which, among other provisions, required an on-shift examination of the dust control parameters before coal production begins on each MMU to assure compliance with the dust control parameters specified in the ventilation plan. Based on the recommendations of MSHA's Coal Mine Respirable Dust Task Group (MSHA, 1992), this requirement is intended to focus attention on the need for properly functioning dust controls before production begins. On-shift examinations of dust control parameters under existing § 75.362 are one important component for an effective respirable dust control strategy. Recent advances in technology make it feasible to continuously monitor certain parameters, such as air quantity and velocity and spray water flow rate and pressure (Spencer, et al. 1996). Existing §75.362 encourages the use of such monitors as it would eliminate the need for periodic physical measurements of some dust controls to verify if they are operating properly. Although current technology allows real-time data to be obtained on certain dust control parameters such as air quantities, MSHA is not aware of its use by any operator. Since establishment of the first comprehensive dust standards in 1969, the implementation of ventilation plans by mine operators and their enforcement by MSHA has had a significant impact on control of dust levels in underground coal mines. For example, based on federal mine personnel sampling results, the average dust concentration in the environment of a continuous miner operator (occupation code—036) has been reduced by 87 percent over the past 32 years, from 7.7 mg/m 3 to approximately 1.0 mg/m 3 . This accounts for the significant decline in the percentage of operator continuous miner designated occupation (DO) samples with concentrations of 2.1 mg/m 3 or higher, from 49 percent (over 32,000 samples/shifts) in 1971, to 7 percent (over 1,250 samples/shifts) during the first three quarters of 2002. Analysis of all valid operator DO samples collected during the same time period as above indicates that in 1971, 53,463 (44 percent) of the 122,404 shifts sampled, were at or above 2.1 mg/m 3 , compared to 1,450 (7 percent) of the 19,336 shifts sampled in 2002 (MSHA, DO Samples by Calendar Year, 2002). Despite this progress, MSHA has found evidence that a significant number of overexposures still occur on the shifts sampled during which the approved dust control parameters are operating at or above approved levels. This evidence suggests that it is highly probable that some miners are overexposed to respirable dust on shifts not sampled by either the operator or by MSHA. In addition, recent medical surveillance data suggests that miners continue to be at risk of developing simple coal workers' pneumoconiosis (CWP), progressive massive fibrosis (PMF), and silicosis (Elam, April 1999). Two expert panels, that reviewed the federal program designed to prevent pneumoconiosis among coal miners, found that certain aspects of the current respirable dust program limit MSHA's ability to determine the adequacy of the dust control parameters under typical mining conditions. Both the Coal Mine Respirable Dust Task Group, (Task Group) an interagency task group established in 1991 by the Assistant Secretary for Mine Safety and Health, and the Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers, (Dust Advisory Committee) established in 1995 by the Secretary of Labor, considered all aspects of the respirable coal mine dust control program and made recommendations for improvement. In addition, in November 1995, NIOSH issued a criteria document that contained recommendations to improve miner health protections. D. Coal Mine Respirable Dust Task Group In response to concerns about the Federal coal mine dust program (MSHA, 1992), MSHA's Task Group undertook an extensive review of the program to control respirable coal mine dust and made recommendations to improve the program in 1991. As part of that review, MSHA developed a special respirable dust “spot inspection program” (SIP). This program was designed to provide the Agency and the Task Group with information on the dust levels to which underground miners are typically exposed. The Task Group found that MSHA's current program did not promote the development and implementation of quality plans. Based on its review of a representative number of dust control plans, the Task Group found that some plans lacked specificity or did not include all the dust control parameters actually used. For example, the plans for three major underground coal mines listed the air quantity, the primary means of controlling concentrations of respirable coal mine dust, to be 18,000 cubic feet per minute (cfm) in the mining section. The actual quantities measured by MSHA samples at these mines during the SIP varied from 40,000 cfm to over 120,000 cfm. Based on a review of MSHA Form 2000-86 (Revised), Respirable Dust Sampling and Monitoring Data, similar differences were found between air quantities specified in approved ventilation plans and the levels observed at a number of longwall MMUs inspected in 1999. For example, 20 of the 47 longwall MMUs were using significantly more air than specified in the ventilation plan (MSHA, September 1999). Under these circumstances, it would be impossible to assess whether the air volume specified in the plan was adequate to maintain dust concentrations at or below the applicable dust standard. It should be noted that air quantities, air velocities, water spray pressures, and other control parameters, specified in the plan are considered to be minimum requirements and MSHA encourages mine operators to exceed their plan parameters, but only after the levels specified in the plan have been shown to be effective under the conditions in effect during sampling. In addition, a lack of specificity in some plans made it difficult for MSHA samples to determine whether the operator was complying with the approved plan. Although several plans indicated that the mining equipment was to be provided with water sprays, the plan did not specify the location of the sprays or the water pressure at the spray nozzle. Currently, MSHA relies on information provided by the operator to determine at what production level the plan should be evaluated. No production records are required for each MMU. Although operators must submit production data on a quarterly basis, the data is compiled for the entire mine. In addition, these quarterly reports provide information on the amount of clean coal produced, which are much lower than the tonnage of total material produced, and are not useful for establishing what constitutes “normal production shifts” for sampling purposes. The Task Group determined that the use of low production levels for evaluating the effectiveness of dust control parameters can result in marginal or inadequate plans. Therefore, the Task Group recommended that MSHA require mine ventilation plans to be effective under typical mining conditions. A more detailed discussion of the impact of production on the quality of dust control parameters specified in mine ventilation plans is contained in sections III.C.1. and IV.B. of this preamble. A survey conducted by MSHA in August of 2002 found that 48 percent of producing MMUs worked at least a 9-hour shift. The Task Group concluded that current regulations limiting the duration of sampling to eight hours do not provide for adequate assessment of respirable dust exposure during nontraditional shifts of more than eight hours. Implementation of the Task Group recommendations would have required regulatory change. The effort to implement these changes was suspended pending the deliberations and recommendations of the Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers, which was convened in 1995. E. NIOSH Criteria Document On November 7, 1995, MSHA received the document, Criteria for a Recommended Standard: Occupational Exposures to Respirable Coal Mine Dust, (Criteria Document) from the National Institute for Occupational Safety and Health (NIOSH). That document contains recommendations to minimize the health risks encountered by surface and underground coal miners due to their occupational exposure to respirable coal mine dust and crystalline silica, hereafter referred to as “quartz.” According to NIOSH, By means of criteria documents, NIOSH communicates these recommended standards to regulatory agencies (including the Occupational Safety and Health Administration (OSHA) and MSHA) and to others in the community of occupational safety and health * * *. In addition to transmitting these documents to the Department of Labor, NIOSH also distributes them to health professionals in academic institutions, industry, organized labor, public interest groups, and other government agencies. (NIOSH, 1995, p. iii). Pursuant to the Mine Act, MSHA was required to issue a public response to this criteria document within 60 days. The statutory deadline for MSHA's response fell on January 7, 1996. In the fall of 1995, there was a lapse in funding for the Federal government, and the Department of Labor was unable to take timely action on this matter (61 FR 731). On April 25, 1996, MSHA published its response to the Criteria Document in the Federal Register (61 FR 18308) stating it would develop its regulatory response to the Criteria Document in conjunction with its response to the outcome of the Dust Advisory Committee. (See section II.F.). Some commenters criticized the earlier proposed rules for not addressing all the recommendations of the Criteria Document. During the August 2000 hearings when these comments were made, a NIOSH representative stated, “* * * strong steps are necessary * * * oftentimes they do need to be incremental in nature.” Among the relevant recommendations from the Criteria Document raised by commenters were the following: • Sampling should be conducted with a device that operates in accordance with NIOSH Accuracy Criteria Document, using the international definition of respirable dust. • Single-shift measurements should be used to determine noncompliance. • The exposure limit for respirable coal mine dust should be limited to 1.0 mg/m 3 as a time-weighted-average (TWA) concentration for up to 10 hours per day, during a 40-hour workweek. • There should be a gravimetric standard for silica of 0.05 mg/m 3 as a TWA for up to 10 hours per day, for a 40-hour workweek. • Sampling goals should include determining the effectiveness of a dust control system and determining compliance with exposure limits to ensure that exposure conditions are comparable between shifts which are sampled and those which are not. • Engineering controls and work practices should reflect reasonable efforts to reduce exposures to respirable coal mine dust below the exposure limit. • MSHA should not make an upward adjustment of the exposure limit to account for measurement uncertainties ( i.e., citation threshold values (CTV)). (See section III.A.4.a.). • Continuous monitoring devices should be developed for use in sampling respirable coal mine dust. • Sampling frequency should be enough that a significant and deleterious change in the contaminant generation process or exposure controls is not permitted to persist. MSHA has carefully considered the applicability of each NIOSH recommendation to reduce miners' exposure to respirable coal mine dust, and the agency has integrated these recommendations into our programs, policies, and promulgation of standards. The proposed rule published today are, in part, responsive to NIOSH's recommendations. For example, the single sample rule, for which the record is reopened in today's Federal Register notice is responsive to the Criteria Document. This rule was jointly developed with NIOSH. The two recommendations regarding exposure limits for respirable coal mine dust and quartz dust are beyond the scope of either the single sample or plan verification proposed rules. MSHA and NIOSH agree that the level of “coal production significantly affects the amount of airborne respirable coal mine dust” (NIOSH 1995, p. 86). NIOSH recommended that “The mine operator, therefore, should establish a production-level threshold to ensure that exposure conditions are comparable between sampled and unsampled shifts'' (NIOSH, 1995, p. 86). NIOSH recommended that, for a production shift to be considered a normal production shift, it must produce at least 80% of the average production, over the last 30 production shifts. Through this plan verification proposed rule, MSHA would require operators to design their ventilation plan to be effective in controlling respirable coal mine dust at or above the “verification production level” (VPL). The VPL is defined as the tenth highest production level recorded in the most recent 30 production shifts. This quantity generally exceeds the production criteria recommended by NIOSH by a substantial amount. In addition, for MSHA to approve an operator's mine ventilation plan, the plan's dust control parameters must be shown to be effective in meeting the verification limits of 2.0 mg/m 3 for respirable coal mine dust and 100 μg/m 3 for respirable quartz dust, under typical mining conditions. MSHA expects that most ventilation plans will be verified at or below those values. Therefore, for most mechanized mining units (MMUs), engineering controls will be in place that can control respirable coal mine dust at or below the exposure limit. (See chapter IX. Costs in the Preliminary Regulatory Economic Analysis (REA) for details). Citation threshold values (CTV) are calculated to ensure that citations are issued only when a single sample measurement demonstrates, with at least 95-percent confidence, that the applicable dust standard had been exceeded. 2 Thus, before issuing a citation, the Secretary requires a high level of confidence that there has been an overexposure. Even so, a dust concentration measurement that falls between the applicable dust standard and the corresponding CTV does not demonstrate that the sampled environment is in compliance. MSHA would identify such environments for further sampling to determine if engineering controls are adequately protective. 2 CTVs are listed in Table 70.2 As mentioned earlier, several commenters to the 2000 proposal expressed concern that, under MSHA's proposed sampling program, the number of shifts to be sampled would be less than under the current operator and MSHA sampling programs combined. Although MSHA will sample fewer shifts than what was recommended by the Dust Advisory Committee, the number of compliance determinations per MMU will not decrease. Under the existing sampling programs, each MMU averages 10 compliance determinations per year. 3 Each of these compliance determinations is based on the average of five 8-hour exposure measurements. (See III.A.2. Post-1980 Sampling Program). Under this proposed rule, each MMU will average significantly more compliance determinations annually using the results of single sample measurements taken by MSHA personnel (30 CFR 70.202). 4 This increase does not reflect the additional compliance determinations that will be made as a result of sampling, concurrently with MMUs, each intake DA, roof bolter DA and outby occupations. 3 Currently, six of the ten compliance determinations are based on the average of five operator, “designated occupation” (DO) exposure measurements. Each of these measurements is collected on a different shift within a bimonthly cycle. The remaining four determinations are based on the average of five inspector samples taken quarterly on different occupations from a MMU. Since the publication of the earlier proposed rule, the number of yearly MSHA sampling inspections at each MMU was reduced from six to four. This was the result of the impact on Agency resources due to a decision by the Federal Mine Safety and Health Review Commission that violations of the applicable dust standard must be based on samples taken on multiple shifts. Prior to that decision, MSHA compliance decisions were based on multiple samples taken on a single-shift. Accordingly, there has been a need to increase the number of shifts of MSHA sampling at MMUs where overexposures are found on the first sampling shift. This results in fewer sampling inspections being available at other MMUs. 4 On a re-occuring basis MSHA will sample an average of five different occupations on each producing MMU. Since every measurement will be compared with the CTV corresponding to the applicable dust standard in effect, MSHA will be making significantly more compliance determinations yearly than under the current operator and MSHA sampling programs combined. The new sampling program will be far more effective in monitoring the quality of the mine air that miners must breathe, and in preventing overexposures on individual shifts, because MSHA will be making compliance determinations using measurements that are more representative of the dust concentrations to which miners are exposed on individual shifts. As such, MSHA believes the new MSHA sampling program addresses the NIOSH recommendation that sampling be conducted “frequently enough that a significant and deleterious change in the contaminant generation process or exposure controls is not permitted to persist” (NIOSH, 1995, p. 85). Significant progress in monitoring technology has been made since MSHA published the earlier proposed rule on plan verification. The agency has been informed by NIOSH that a continuous dust monitor may be available for in-mine use by the middle of 2004. Accordingly, as recommended in the criteria document, MSHA is proposing a new standard that would permit operators to use this new technology in conjunction with existing dust controls specified in the ventilation plan to prevent overexposures on individual shifts. Today's proposed rule does not adopt all the Criteria Document recommendations since many of the recommendations are outside the scope of these rules. However, MSHA continues to be committed to the principles that “preventive efforts [must] be focused primarily on reducing work exposures (NIOSH, 1995).” The Secretary of Labor and the Secretary of Health and Human Services believe that miners' health will be further protected from the debilitating effects of occupational respiratory disease by limiting their exposures to the applicable dust standard through the implementation of the single sample rule which conforms to the NIOSH Accuracy Criteria. Furthermore, as stated by NIOSH during the hearings: NIOSH does support efforts by MSHA and anyone else that will reduce miners' exposures to dust and silica dust and also eliminate or at least reduce significantly the incidence of the diseases * * *. MSHA believes that this proposed plan verification rule provides an improved program for measuring, monitoring, and reducing overexposures to respirable coal mine dust and quartz dust, under typical mining conditions. As such, it greatly advances the level of health protection afforded underground miners and is consistent with recommendations issued by NIOSH in its Criteria Document. F. Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers On January 31, 1995, the Secretary of Labor established the Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine Workers (Dust Advisory Committee). The Dust Advisory Committee was chartered to “make recommendations for improving the program to control respirable coal mine dust in underground and surface mines in the United States.” The Dust Advisory Committee identified and addressed many of the same issues considered by the Task Group. Findings and consensus recommendations were developed for each issue (MSHA, 1996). The Dust Advisory Committee concluded that the dust control portion of the mine ventilation plan is the key element of an operator's strategy to control respirable dust in the work environment. They concluded that the initial evaluation, approval, in-mine verification and monitoring to demonstrate the effectiveness of the operator's proposed dust control plan is critical for the protection of miners from lung disease. Also, believing that the credibility of the current system of mine operator sampling to monitor compliance with exposure limits has been severely compromised, the Dust Advisory Committee concluded that restoration of miner and mine operator confidence in the respirable coal mine dust sampling program should be one of MSHA's highest priorities. Accordingly, there was unanimous agreement that in order to restore confidence in the program MSHA should take full responsibility for all compliance sampling currently being carried out by mine operators under 30 CFR parts 70 and 90. The November 1996 Dust Advisory Committee Report recommended numerous improvements for the federal program to protect miners from simple CWP, PMF, and silicosis. Of these, the following have been incorporated in this proposed rule: 1. MSHA will take full responsibility for all compliance sampling (periodic and abatement) at a level which ensures that representative samples are collected of respirable dust exposures under usual conditions of work without adversely impacting the Agency's resources and responsibilities. 2. Operators would be required to verify, through sampling, the effectiveness of the dust controls in the ventilation plan prior to approval by MSHA. The plan must be verified utilizing only those controls that are listed in the plan. In addition, mine operators would sample designated MMUs quarterly to ensure that the dust controls continue to protect miners from overexposure. 3. MSHA will redefine the range of production levels which must be maintained during sampling to verify the plan. The value will be sufficiently close to maximum anticipated production levels in order to reasonably ensure that the plan is effective under typical operations. 4. MSHA will review compliance and production records to determine when there is a need for plan verification and modification. 5. MSHA would allow mine operators to use newly developed technology to continuously monitor the work environment and prevent overexposures on individual shifts. This proposed rule is intended to eliminate overexposures on individual shifts and to restore the confidence of miners and mine operators in the respirable coal mine dust sampling program by addressing the shortcomings identified by the Task Group and the Dust Advisory Committee in the current respirable coal mine dust program. This proposed rule would revise the operator dust sampling programs under 30 CFR parts 70 and 90 and require the implementation of mine ventilation plans demonstrated to be effective in maintaining respirable dust at or below applicable dust standards on each shift. These ventilation plans will be verified through sampling by the mine operator, and the plans' effectiveness may be monitored on a quarterly basis by the operator. MSHA intends to periodically monitor operator verification sampling and on a recurring basis will conduct sampling on each MMU to assure compliance with the provisions of the ventilation plan and the applicable dust standard. A notice reopening the record regarding the use of single-shift sample measurements of respirable coal mine dust to determine average concentration is also published in today's Federal Register . MSHA recognizes that the Dust Advisory Committee made several recommendations that also impact on surface coal mine workers. These surface coal mine issues are beyond the scope of this proposed rule and will be addressed by the Agency at a later date. In response to comments received, MSHA has specifically stated in this proposed rule that the representative of miners has the right to observe MSHA sampling with no loss of pay as recommended by the Dust Advisory Committee. The proposed rule also allows the miners' representative the opportunity to participate in operator sampling to verify the ventilation plan. However, such participation would be with no loss of pay, only when MSHA personnel are present to observe that sampling. This proposed rule does not specifically address the committee's recommendations concerning specialized miner training on verification sampling procedures. However, MSHA does intend, during the implementation of any final rule, to provide training to miners, miners' representatives and mine operators on the requirements of the new regulations. In addition, agency personnel are available to provide training to miners and their representatives on the verification procedures as needed. This proposed rule does not incorporate full-shift sampling as recommended by the Dust Advisory Committee. In this proposed rule, MSHA does require that verification and operator quarterly sampling occur for the entire production shift since the purpose of that sampling is to evaluate the effectiveness of the dust controls on the MMU. Therefore, outby travel time is not included. With regard to compliance sampling by MSHA, the agency believes that sampling portal to portal for the entire shift or eight hours, whichever is less, provides the agency with sufficient data to determine if the dust control measures outlined in the ventilation plan are adequate and being followed or to determine if overexposures are occurring. Although the Dust Advisory Committee also recommended that MSHA adjust the exposure limit to account for extended work weeks, such a change is considered to be outside the scope of this rulemaking. MSHA has clarified in this proposed rule that the Secretary will cite for overexposure when an MSHA sample demonstrates that the applicable dust standard has been exceeded, based on the citation threshold value (CTV). In response to concerns that, by using a CTV, MSHA is increasing the standard, MSHA has clarified that respirable dust concentration levels must always be maintained at or below the applicable dust standard. In order to obtain ventilation plan approval from MSHA, operators must demonstrate that the dust control parameters adequately prevent excessive dust concentrations on individual shifts. The plan's effectiveness is evaluated against the applicable dust standard itself—not the CTV—and must be demonstrated at a high level of confidence. This proposed rule also provides for the limited use of measures to supplement engineering or environmental controls for exposure control. These supplemental measures would be permitted at certain times when the Administrator for Coal Mine Safety and Health has determined that all feasible engineering and environmental controls have been applied and the mine operator is unable to verify the ventilation plan. Supplementary controls may also be approved by MSHA for short-term use to protect individual miners when operators encounter intermittent, adverse conditions under which exposures cannot be maintained within the applicable standard using the approved dust control parameters. Finally, MSHA received comments suggesting that this rule address the Dust Advisory Committee recommendation to establish a separate silica standard. This issue is outside the scope of this rule. III. General Discussion A. Proposed Reforms to the Respirable Dust Monitoring Program One of the Dust Advisory Committee's key recommendations was that MSHA take full responsibility for all compliance sampling at a level which assures representative samples of respirable dust exposure under usual conditions of work. This was based on the belief that one of MSHA's highest priorities must be to restore the confidence of miners and mine operators in the respirable coal mine dust sampling program. Accordingly, MSHA is proposing to revise the operator dust sampling programs under current 30 CFR parts 70 and 90 and to take full responsibility for all compliance sampling ( i.e. , periodic and abatement sampling) in a manner that it believes will be more protective than the current operator sampling program. MSHA intends to monitor miners' dust exposure and compliance with the dust control provisions of the approved mine ventilation plan, or with the respirable dust control plan for a Part 90 miner at underground mines, in accordance with the procedures and guidelines established in Chapter 1 of the Coal Mine Health Inspection Procedures Handbook. (a) Compliance Sampling MSHA will routinely collect samples from the working environment of the DO, Part 90 miners and, if available, four or more other occupations working in each producing MMU. The data from this sampling will be utilized by MSHA to formulate an effective compliance sampling strategy that focuses on the performance of individual sampling entities and to target MMUs for operator quarterly sampling. The strategy will be detailed in the Agency's respirable dust inspection procedures. Each DA inby the section dump point, such as intake and roof bolter DAs, and other DAs that can be sampled concurrently with the MMU will also be sampled routinely. If the MMU sampled is operating with approved supplemental control measures, the five or more occupations sampled will include the DO and all miners whose exposure is being controlled through the use of PAPRs or verifiable administrative controls. Since MSHA's inspections are unannounced, the primary objective is to assess the respirable dust conditions to which miners are exposed under the operating conditions in effect at the time of sampling ( i.e. , production level, air quantities and velocities, etc. ). All respirable dust samples collected will be considered valid, unless voided by MSHA for other reasons, such as a malfunctioning pump. Because the primary purposes are to measure the quality of the mine air miners breathe and to evaluate the operating conditions on a particular shift, the Agency believes there is no reason to invalidate any sample if a certain level of production is not attained as under the previous sampling procedures. Compliance sampling results, however, will provide MSHA personnel with sufficient information to make a sound engineering judgement about the effectiveness of the dust control parameters in use. Also, since the purpose of this sampling is not intended to evaluate plan effectiveness, the term “full shift” for purposes of compliance and abatement sampling will continue to mean the entire work shift including travel time but excluding any time in excess of 480 minutes. This is different from the definition of “full shift” that is proposed for verification sampling. For purposes of verification sampling, “full shift” would mean an entire work shift during which material is produced by a MMU. MSHA solicits comments on whether full shift for compliance sampling should be defined in the same way as for verification sampling. MSHA is proposing to continue the current policy of sampling outby locations only once per year. The historical data that has been collected by MSHA personnel at outby locations confirms our belief that, if the working sections are in compliance with the applicable dust standard and if controls are in place at outby dust generating locations, workers throughout the mine are being protected from overexposure. MSHA personnel will continue to sample each DA located outby the section dump point on a production shift and any other dust-generating sources that can be sampled concurrently with the DA. MSHA will issue a citation for noncompliance when a valid single sample measurement, expressed as an equivalent dust concentration, meets or exceeds the Citation Threshold Value (CTV) corresponding to the applicable dust standard in effect. The current CTVs are contained in Table 70.2 of this proposed rule. The CTVs and an explanation of how they were derived was originally published in the Federal Register notice of February 3, 1998 (63 FR 5687), entitled “Coal Mine Respirable Dust Standard Noncompliance Determinations.” As explained in that notice and in Appendix “C” of the current notice of proposed rulemaking, each CTV is calculated so that citations are issued only when a single-shift measurement demonstrates noncompliance at least at a 95 percent confidence level. Noncompliance determinations based on single-shift measurements will reduce the chances for failure to cite cases of noncompliance. According to the federal sampling inspections conducted in 1995, only 132 MMUs were found to be in violation of the applicable dust standard. These MMUs were cited under the existing enforcement policy of measurement averaging, compared to 545 MMUs that would have been citable using single sample measurements in combination with the CTV table. This clearly demonstrates that the new enforcement strategy will not compromise miners' health, instead it would have identified 413 additional instances of overexposure. Otherwise, these overexposures would continue to go uncorrected under the previous policy of measurement averaging. Many commenters believed that miners would receive greater protection if MSHA cited for noncompliance whenever any single-shift measurement exceeded the applicable dust standard. MSHA has carefully considered, but rejected this suggestion. Such citations may not be sustained with a sufficient degree of confidence for enforcement action. If the mine environment is sufficiently controlled, the likelihood that a particular measurement exceeds the applicable dust standard, but not the CTV, due to measurement error, can actually exceed the likelihood that the measurement exceeds the standard due to excessive dust concentration. A thorough technical discussion of this issue is provided at 63 FR 5709-5712 (Appendix D of the Federal Register notice cited above) and is incorporated into this notice by reference. Basing noncompliance determinations on a single sample measurement, in conjunction with the CTV table, will improve working conditions for miners. Many commenters contended that a policy of citing in accordance with the CTV table, rather than citing whenever a measurement exceeds the applicable dust standard, would effectively increase the allowable dust concentration limit. These commenters expressed concern that MSHA was raising the applicable dust standard when it proposed to cite violations only when the measurement demonstrated noncompliance at a high level of confidence. The CTVs do not raise the applicable dust standard. Instead, MSHA must ensure a sufficiently high level of confidence in noncompliance determinations to withstand a legal challenge. For those MMUs with measurements above the applicable dust standard but below the CTV, MSHA will thoroughly review their dust control parameters. Special emphasis will be directed to working environments required to comply with standards below 2.0 mg/m 3 . As a result of such reviews MSHA may initiate additional sampling. The Secretary has concluded that using single sample measurements for noncompliance determinations in accordance with the CTV table neither increases nor decreases the applicable dust standard. Operators are required to maintain compliance with the applicable dust standard at all times. Dust controls must be verified as adequate to maintain dust concentrations at or below the applicable dust standard on all shifts, not merely at or below the CTV. If a measurement exceeds the applicable dust standard by an amount insufficient to warrant citation—that is, the level does not meet or exceed the CTV—MSHA will target that mine or area for additional sampling to ensure that dust controls are adequate. (b) Abatement Sampling Under this proposed rule, MSHA would also assume responsibility for all abatement sampling. As recommended by the Dust Advisory Committee, MSHA would utilize single samples to demonstrate abatement. Since the criteria under which the effectiveness of ventilation plans are required to be verified are significantly more stringent than those for compliance sampling, MSHA does not anticipate issuing many citations to MMUs and sectional DAs. When a mine operator is cited for violation of the applicable dust standard, MSHA will require that approved respiratory equipment be made available to the affected miners in accordance with existing § 70.300 of this part. The mine operator also will be required to review the dust control practices to identify the cause of the excessive dust concentration and correct any deficiencies within the abatement period fixed in the citation. The mine operator must notify the district manager of the corrective measures taken within 24 hours of implementation to enable MSHA to determine whether abatement or verification sampling should be scheduled. This determination will be based on the review of the information the mine operator provides and the latest inspection reports documenting the measured quantities of the dust control parameters that were in use at the time the citation was issued. If it is determined that the existing dust control parameters are likely to be adequate to maintain compliance, the district manager will initiate abatement sampling under § 70.218. For example, if the operator believes that the overexposure was caused by improper work practices, the proper course of action would be to review these work practices with the affected miners rather than requiring the operator to upgrade the engineering or environmental controls. Since there was no need to change the plan parameters, MSHA would initiate abatement sampling in this particular case. If, on the other hand, the district manager determines that the dust control parameters may not maintain respirable dust levels at or below the applicable dust standard, the mine operator will be notified to revise the dust-control portion of the mine ventilation plan as specified in this Part. When MSHA samples a MMU for abatement purposes, single samples will be collected from the working environment of the cited occupation and, if available, four other occupations that will include the DO. Like compliance sampling, abatement sampling will be conducted portal to portal, for the entire shift or 8 hours, which ever is less. When sampling DAs and outby occupations, MSHA will collect a similar single-shift abatement sample from the environment of the cited DA or occupation. A citation for excessive dust will be terminated when all valid abatement samples collected are at or below the applicable dust standard. The subsequent action form will clearly and fully describe the action taken to abate the violation. Mine operators may be required to revise the ventilation plan in accordance with § 75.370(a)(2) of this title depending on the type of corrective measures taken to abate the violation. This includes, at a minimum, the actual dust control parameters that were in effect when MSHA sampled. If the district manager requires the mine operator to initiate the plan verification process under § 70.206 of this part instead of abatement sampling, the citation for excessive dust will be terminated after a revised plan has been verified to be effective for the current mining conditions. (c) Operator Verification Sampling and Quarterly Sampling Mine operators are required, under this proposed rule, to verify, through sampling, the effectiveness of the dust control parameters for each MMU prior to receiving MSHA approval of the mine ventilation plan. In addition, certain mine operators must sample quarterly each DO, any occupation required to wear a PAPR or using administrative controls, and any other occupation designated by the district manager. The purpose of the quarterly sampling is to evaluate the continued effectiveness of the approved dust control parameters. These provisions are discussed elsewhere in this proposed rule. (d) Advantages of MSHA Compliance Sampling Over the Existing Program Under section 101(a)(9) of the Mine Act, no health standard promulgated under the Act shall reduce the protection afforded miners by an existing mandatory health standard. The joint promulgation of this proposed rule and the proposed single sample rule, would provide protection to miners from the debilitating effects of occupational respiratory disease by limiting their exposures to respirable coal mine dust and quartz dust on every shift: • Providing and maintaining a work environment free of excessive levels of respirable dust is essential for long-term health protection. While monitoring of the work environment provides an indication of how effective the existing dust control measures are, monitoring alone does not control dust levels. Requiring mine operators to implement and maintain dust control parameters which have been determined effective under typical mining conditions, will provide reasonable assurance that no miner will be overexposed on individual shifts. • Implementing single-shift sample determinations will more likely detect excessive dust concentrations and thus protect miners. Averaging samples taken on multiple shifts can mask overexposures on individual shifts. Although fewer shifts will be sampled under this proposed rule, MSHA believes the revised sampling methodology will provide a more accurate representation of dust conditions to which miners are exposed. • Under the existing operator sampling program, only the DO is sampled. Under the new sampling program, MSHA will sample multiple occupations on the same shift. As a result, MSHA will make several times as many compliance determinations as under the previous operator and MSHA sampling programs combined, providing a more comprehensive assessment of dust conditions to which miners are exposed. • Since MSHA will be conducting all compliance sampling, the Agency will be able to monitor the dust control parameters and work practices in effect during sampling. This will enable MSHA to determine the effectiveness of the mine operator's dust control program. • Unlike the current sampling program, which allows operators' control over when to sample and under what operating conditions, MSHA's visits for compliance sampling will be unannounced. As a result, all phases of the mining cycle are likely to be sampled eventually ( i.e. , construction activity, longwall start-up, turning crosscuts, etc. ), and samples should be more representative of typical mining conditions. • The miners' representative will have walkaround rights during all MSHA sampling, thereby increasing miners' confidence in the dust sampling program. B. Procedures for Setting the Applicable Dust Standard When Quartz Is Present 1. Proposed Procedures Consistent with MSHA's proposed rule to assume full responsibility for compliance sampling, the Agency also proposes to rely only on MSHA samples, i.e. , compliance or abatement samples, as the basis for setting the applicable dust standard when quartz is present. As discussed below, while today's proposed rule would reduce the burden and cost on mine operators to take and submit optional samples, it would not diminish the advantages afforded operators under the current program. In particular, it continues to consider temporal variability associated with quartz determinations by averaging three MSHA samples collected on different shifts. MSHA believes that results under this revised process will be more representative of the quartz levels to which miners are exposed. Unlike the current process, which may cause a standard to be set based on the quartz content of an individual MSHA sample, three valid MSHA samples would be used to set a reduced standard under the revised procedures (64 FR 65671). 5 Since, under the rules being proposed today, MSHA intends to frequently sample underground mines and surface mines, MSHA personnel will have no difficulty in collecting the required number of samples to arrive at the average quartz percentage. If initial sampling shows that miners may be exposed to excessive levels of quartz, MSHA intends to sample at a greater frequency to ensure that miners are being protected. This level of sampling should also allay any operator concerns regarding the collection of “misleadingly high” samples during atypical periods. MSHA also intends to begin reporting quartz levels to the nearest tenth of a percent. This will be more protective for the miner than the current truncation of results to a full percentage point. 5 Unlike MSHA's objective in compliance sampling, the objective in measuring quartz content is to establish a reduced standard that will apply to all shifts. This enables an operator to design a ventilation plan that will be protective on every shift. Therefore, it is appropriate to estimate the quartz content by averaging quartz measurements obtained over an extended time period. Under the revised procedures, when an MSHA sample contains more than five percent quartz, the agency will average the percent of quartz present in three most recent MSHA respirable coal mine dust samples to set the applicable dust standard. If a MMU, DA, Designated Work Position (DWP) at an underground mine, or Part 90 miner is already on a reduced standard, a new applicable dust standard will be established by averaging the results of the first two MSHA samples, taken under the revised procedures, with the quartz percentage associated with the reduced standard in effect. If fewer than two MSHA samples are taken, the existing reduced standard will continue to remain in effect. Assume a MMU is on a 1.0 mg/m 3 standard (10 percent quartz). If the first MSHA sample contains 7.2 percent of quartz, the existing standard of 1.0 mg/m 3 would continue to remain in effect. If, however, the next sample contains 16.1 percent, the average quartz percentage would be 11.1 percent [(10.0% + 7.2% + 16.1%) 3 = 11.1%], resulting in a 0.9 mg/m 3 -standard (10 11.1% = 0.9 mg/m 3 ). For any MMU, DA, DWP, or Part 90 miner not on a reduced standard, MSHA will collect and analyze three samples for quartz to determine if a reduced standard is warranted. Under the revised procedures, if the newly-established standard is lower than the one in effect, the new standard will become effective seven days after the date of the notice informing the mine operator of the change in the applicable dust standard. However, if it is higher than the current standard, the newly-established applicable dust standard will become effective on the date of the notice. As published elsewhere in today's Federal Register , MSHA is proposing to take enforcement actions on the basis of single-shift sample measurements. For entities on reduced standards, MSHA would delay enforcement action until the sample is analyzed for quartz. If an exposure measurement significantly exceeds the existing standard and the quartz content of that sample would cause the standard to be lowered below the existing reduced standard, the operator will be cited for violation of the applicable dust standard currently in effect. On the other hand, if the quartz content of the sample would cause the applicable dust standard and the corresponding citation threshold value (CTV) to increase so that the single-shift sample measurement would no longer indicate noncompliance, no citation will be issued. This is illustrated by way of the following example. For example, suppose that the MMU is on a 1.3 mg/m 3 standard and a single-shift sample measurement of 1.6 mg/m 3 is obtained. Since this measurement exceeds the CTV value, the operator is in violation of the standard. However, analysis of the DO sample shows that the sample contained 5.6 percent quartz which, if averaged with the previous two MSHA quartz levels, would result in a 1.7-mg/m 3 standard. This indicates that the quartz level in the environment of the DO has changed, indicating that the current standard is no longer valid. Therefore, since the original measurement of 1.6 mg/m 3 is less than the 1.7-mg/m 3 standard that could have been in effect for the shift sampled, a citation would not be issued. Since MSHA samples are viewed to be more representative of the respirable dust concentration to which miners are exposed, MSHA is proposing to revise section 70.101 to clarify that the Secretary will determine the quartz level by sampling. Operator samples would no longer be submitted to determine the applicable dust standard. It is our belief that the procedures being proposed today for setting reduced standards will be more protective for the miners than those in effect at this time. The revised approach provides for stringent monitoring of miners' exposure to quartz which is consistent with the Dust Advisory Committee's recommendation that MSHA increase surveillance and reduce exposure to this serious health hazard. As under the current program, if operating conditions change following establishment of a lowered applicable dust standard and affect the level of quartz in the working environment, MSHA intends that mine operators or miners' representatives will be able to request MSHA to conduct a quartz reevaluation. 2. Validity of Averaging Percentages The average quartz percentage that MSHA intends to use to set the applicable dust standard for a particular sampling location or area of a mine would be determined in accordance with accepted mathematical procedures for arriving at an average value from a set of values ( i.e. , adding together the individual quartz percentages and dividing by the number of analyses that are in the set). MSHA believes that this is the most appropriate method to use. One commenter who responded to a draft 1999 program policy letter (November 23, 1999, 64 FR 65671) concerning this issue contended that MSHA's approach of arriving at the average quartz percentage was mathematically incorrect. This commenter recommended that, to more accurately reflect the true quartz concentration, the average quartz percentage be calculated by dividing total mass of quartz in micrograms by the total mass of dust collected (based on three samples in the example submitted). In the commenter's example, the average percentage obtained using MSHA's proposed averaging method was larger than that obtained using the commenter's approach. The following two scenarios in Table III-1 clearly demonstrate that MSHA's intended averaging method does not always result in a larger average quartz percentage value. EP06MR03.000 These examples show that for situations where MSHA would have determined a quartz percentage of 8.0 percent, the commenter's method would yield 9.2 percent in one case and 7.7 percent in the other. C. Respirable Dust Control Program for Underground Coal Mines The primary focus of the underground coal mine respirable dust program is to limit the concentration of respirable dust to which miners are exposed in the work environment. To ensure that miners are not being exposed to excessive concentrations of respirable dust, current regulations require mine operators to: • Design a mine ventilation plan that effectively controls respirable dust under typical mining conditions; • Implement the plan's dust control parameters when approved by MSHA before commencing production; • Maintain the dust control parameters specified in the approved plan and monitor their function and operation through required on-shift examinations; and • Evaluate the effectiveness of dust control parameters with bimonthly samples in order to provide reasonable assurance that such parameters continue to function as intended. In addition, each plan must be suitable to the conditions and mining system in use at the mine. These plans provide detailed requirements for the protection of miners by specifying engineering controls. These engineering controls may include: • The quantity and the velocity of the air current used to ventilate the MMU; • The number, type, and location of water sprays; • The pressure and quantity of water delivered by the sprays; and • Additional environmental controls, such as dust scrubbers or devices which collect mine air and filter out dust particles. Plans also contain procedures for maintenance of dust control equipment used on the mining machine and roof bolter. Mine operators frequently do not describe all dust controls in use at the mine. If such information is not included in the plan, it is impossible for MSHA to enforce those provisions or to determine if the ventilation plan provisions as approved are adequate to protect miners from overexposure. When an operator submits a proposed mine ventilation plan or revision in accordance with § 75.370, the MSHA district office reviews it for completeness and adequacy. The district manager will approve the plan if it meets MSHA requirements, and he or she is confident that the dust control parameters specified will have a reasonable likelihood of maintaining dust concentrations within the allowable limits. Most proposed plans or revisions are approved immediately, or tentatively approved, based on engineering judgement, or experience, or both, until they are assessed by MSHA sampling or, to a lesser extent and only under certain circumstances, by mine operator bimonthly sampling. Generally, MSHA takes samples within 60 days of plan approval. Current regulations prohibit a mine operator from initiating any mining activity without an approved ventilation plan. MSHA allows operators to commence mining by granting tentative approval. However, under the existing process, plans may be implemented which are later determined to be inadequate under typical mining conditions. 1. Proposed Procedures for Evaluating, Approving, and Monitoring Ventilation Plan Requirements The dust control portion of the mine ventilation plan is the key element of an operator's strategy to control respirable dust in the work environment, thereby protecting miners. In recognition of this, MSHA is proposing to make a number of changes to the process for evaluating, approving, and monitoring mine ventilation plans, many of which are based on the Dust Advisory Committee's recommendations. These are addressed in detail under proposed §§ 70.201 through 70.220 of the preamble. Consistent with the Dust Advisory Committee recommendations, MSHA is proposing to add provisions to verify the effectiveness of the ventilation plan in controlling dust, at a production level which will demonstrate the plan's effectiveness under typical operating conditions. Dust control parameters and production associated with samples on a given shift would be recorded in order to demonstrate that parameters specified in the ventilation plan continue to be effective in controlling respirable dust. This proposed rule requires a ventilation plan to include all engineering or environmental controls necessary for maintaining dust concentrations at acceptable levels. A plan must also include any specific work practices or other means used to supplement these controls in order to minimize the dust exposure of individual miners. Unlike plans under the existing program, mine operators will have to identify all measures necessary for achieving continuous compliance with the applicable dust standard in the plan. MSHA would require mine operators to include information on the length of each normal production shift in § 75.371(f) and to specify the VPL, as defined in § 70.2, in every ventilation plan. The VPL is the tenth highest production level recorded in the most recent 30 production shifts. This value will represent the minimum production level at which effectiveness of the plan must be demonstrated. MSHA believes that the current production criteria used to evaluate plan effectiveness may not adequately represent typical conditions under which miners work. Requiring that plans be verified at or above the VPL will provide assurance that excessive dust concentrations will be avoided, even on shifts with higher-than-average production. This is far more protective of miners than the current practice of evaluating plan adequacy based on MSHA samples taken when production can be as low as 60 percent of the average production. Some commenters on the earlier proposed rule expressed confusion about the relative magnitude of the VPL, compared to average production or other possible production criteria. Figure 1 shows a typical distribution of 30 shift production levels recorded at a longwall MMU. As illustrated by this example, the VPL, defined as the 10th highest production achieved during 30 shifts, generally exceeds the average production by a substantial amount. BILLING CODE 4510-43-P EP06MR03.001 BILLING CODE 4510-43-C MSHA proposes to require mine operators to maintain records of the amount of material produced by each MMU during each shift. This will enable operators to establish the VPL. Because verification of a plan's effectiveness is conditioned on the VPL, these records are necessary to ensure that the VPL continues to represent typical production levels. Although a VPL must be included in the ventilation plan, MSHA will not cite mine operators for producing at levels exceeding the VPL. MSHA considers the VPL to be a plan design criteria, not a minimum plan parameter that must be in effect on every shift. The Agency would expect production on a MMU to exceed the VPL on about 33 percent of all production shifts. If the district manager determines that an operator's actual production exceeds the VPL on more than 33 percent of the production shifts over a six-month period and the operator or MSHA samples exceed the applicable standard, the district manager may require that the adequacy of the plan parameters be verified under different operating conditions of production. Under the proposed plan verification procedures, mine operators will be required to verify through sampling the effectiveness of the dust controls specified in the ventilation plan prior to approval of that plan by the district manager. Sampling would occur when production is at or above the VPL specified in the plan and using only those control parameters and other measures listed in the plan. The sampling pumps must be turned on upon arrival on the MMU and remain operational during the entire production shift. The pumps must be turned off upon leaving the MMU. Samples would be collected on multiple occupations which are specified in proposed § 70.206. All verification samples must be transmitted to MSHA. However, no citations would be issued to mine operators if the verification sample results show that the applicable dust standard has been exceeded. Operators would be cited only if they fail to take steps to determine the cause and take corrective action to eliminate the overexposure. The agency would approve a plan only when a sufficient number of verification samples demonstrate, at a high level of confidence, that the plan is effective at production levels at or above the VPL. Unlike the existing program, this proposed rule would allow certain longwall and other operations to use either approved PAPRs, administrative controls, or both, to supplement engineering or environmental controls if the mine operator is unable to verify the ventilation plan. This will be permitted only after the Administrator for Coal Mine Safety and Health determines that the operator has exhausted all feasible engineering or environmental controls. District managers also may allow mine operators to use PAPRs to achieve compliance with the applicable dust standard when unusual operating conditions are encountered briefly and intermittently and the operator believes that the approved plan parameters will not adequately protect all miners from overexposure. The period of time when PAPRs may be used cannot exceed 30 calendar days under this proposed rule. An example of when such approval may be granted is when an operator periodically must mine through rock strata with high quartz content. Finally, under this proposed rule, mine operators also would be required to sample each DO and occupation using PAPRs or administrative controls at least once every three months to evaluate the continued adequacy of the approved plan parameters. As with verification samples, operators would only be cited if they fail to take corrective action to eliminate any overexposure identified through such sampling. D. Hierarchy of Dust Controls 1. Primacy of Engineering Controls Consistent with the Mine Act, engineering or environmental controls have been the principal method used for preventing or minimizing miners' exposure to both primary and secondary dust sources in the workplace over the past 30 years. Engineering controls that are able to manage the amount of dust throughout the work environment give reasonable assurance that all miners in the area will be adequately protected. Well-designed engineering or environmental controls provide consistent and reliable protection to all workers because they are not dependent upon constant human supervision or intervention, except for the periodic checks, to ensure that they are functioning as intended. Under this proposed rule, operators would be required to utilize, on each production shift, all engineering or environmental controls as specified in their mine ventilation plans. These controls will maintain concentrations of respirable dust in the work environment of MMUs at or below the applicable dust standard. Engineering or environmental controls include all methods that control the level of respirable dust by reducing dust generation ( e.g. , machine parameters) or by suppressing ( e.g. , water sprays, wetting agents, foams, water infusion, etc.), diluting ( e.g. , ventilation), capturing ( e.g. , dust collectors), or diverting ( e.g. , shearer clearer, passive barriers, etc.) the dust being generated by the mining process. The importance of using engineering or environmental controls was recognized by the Dust Advisory Committee and by NIOSH in Occupational Exposure to Respirable Coal Mine Dust (NIOSH, 1995). NIOSH recommended that such controls must continue to be relied upon as the primary means of protecting coal miners. The primacy of engineering or environmental controls would be preserved under this proposed rule. The proposed rule requires a mine operator to utilize all feasible engineering or environmental controls, specified in the approved ventilation plan, to reduce concentrations of respirable dust to a level at or below the applicable dust standard. 2. Administrative Controls Administrative controls are another method of avoiding overexposure. Administrative controls refer to work practices that reduce a miner's daily exposure to respirable dust hazards by altering the way in which work is performed. They consist of such actions as rotation of miners to areas having lower dust concentrations, rescheduling of tasks, and modifying work activities. The Task Group found that administrative controls were used increasingly, even when it was feasible to implement additional engineering or environmental controls. The use of administrative controls was found to be increasing at mines employing longwall mining systems. The most frequent administrative control in use consisted of restricting the activities of miners required to work downwind of the longwall shearer operator, the occupation designated as 044 by MSHA. This particular form of administrative control was in use at some of the 51 longwall MMUs that were operating on October 28, 1999. MSHA has observed the use of this particular administrative control, even after changing the location of the DO from the 044 to the 060 occupation—the miner who works nearest the return air-side of the longwall working face. Unlike engineering or environmental controls, to be effective, administrative controls rely on the ability of miners to follow specified procedures. However, difficulty in ensuring that miners adhere to the administrative controls, labor/management agreements, and limitations on the number of qualified miners capable of handling specific tasks may limit the use and effectiveness of such controls. The Dust Advisory Committee Report stated that the use of administrative controls does not reduce the operator's responsibility to maintain ambient dust levels in active workings at or below the applicable dust standard. However, the Dust Advisory Committee noted that “while not a substitute for engineering controls, administrative controls, which restrict the amount of time that miners spend in an area with uniform exposure level, can result in lower personal exposures (MSHA, 1996).” 3. Limitations of Engineering Controls It is MSHA's position that technology is generally available to control respirable dust to, or below, the applicable dust standard at MMUs employing continuous and conventional methods of mining. However, where unusual or adverse conditions are encountered it is possible that available controls may be inadequate to continuously protect all miners from overexposure. This is most likely to occur in areas where high levels of quartz are encountered that may result in the setting of lowered standards on a MMU. However, MSHA recognizes that, unlike other mining systems, longwall MMUs may have acute dust problems. These problems can be caused by the face-ventilation airstream carrying the shearer-generated dust over the miners working along the face downwind of the longwall shearer operator (occupation code 044). This makes it more difficult to control the work environment downwind of the longwall shearer operator on a consistent basis. Improvements in dust control technology have not kept pace with increases in production technology associated with high-production longwall MMUs. Average longwall shift production reported during bimonthly sampling has increased more than six-fold since 1980, from approximately 890 tons per shift (tps) to 5,500 tps in 2002. In fact, 49 percent of the shifts sampled averaged 4,000 to 8,000 tps, while approximately 8 percent of the shifts exceeded 8,000 tps. A major milestone in mining production was achieved in 1997 when a single longwall mine produced more than 1 million tons of coal in a single month (Fiscor, 1998). Unfortunately, as more coal is mined, greater quantities of respirable dust are generated. The increase in longwall production levels has resulted in the generation of far more dust which must be controlled (Webster, et al., 1990; Haney, et al., 1993; O'Green, 1994). According to published literature, several thousand milligrams of respirable dust per ton of coal cut can be formed and liberated during the cutting process (National Research Council, 1980). Of course, the quantity of respirable dust produced by the cutting process can vary greatly, depending on the type of coal, its moisture content, the amount of rock bands in the coal, sharpness of the cutting bits, the particular mining machine, and many other factors. Although a considerable amount of respirable dust is formed by the cutting operation, not all of it becomes airborne. Nevertheless, given the amount of dust that is produced per ton of coal mined, a larger quantity of respirable dust would be generated and released to the mine environment from cutting 8,000 tons of coal than from cutting 4,000 tons. Currently, an operator is not required to produce, on a sampled shift, more than 50 percent of the average production reported during the last bimonthly sampling period. Therefore, dust concentrations on sampled shifts may be substantially lower than what is typical on nonsampled shifts. While significant efforts have been made to implement available control technology, no significant new advancements in longwall dust control technology have been reported since 1989 (U.S. Bureau of Mines, undated). From 1989 to 2002 (Jan.-Sept.), the percentage of operators' longwall DO samples with concentrations of 2.1 mg/m 3 or higher dropped from 22 percent to 14 percent, reflecting the impact of implementing the pre-1990 advances in longwall control technology. Although this represents a significant improvement, especially in view of the six-fold increase in average shift production, the 2002 data suggests that miners continue to be overexposed on a significant number of shifts. Over the past ten years, MSHA and the former U.S. Bureau of Mines, now part of NIOSH, have made unsuccessful efforts to conduct a joint research program that would evaluate the effectiveness of available longwall dust control technology. The objective of such research would have been to quantify the effects of employing all state-of-the-art dust control technology available for a longwall operation. Unfortunately, the two agencies have been unsuccessful in finding an industry partner to participate. MSHA has worked with mine operators on an individual basis to determine the effectiveness and feasibility of existing and additional respirable dust controls on a particular longwall. However, the design and goals of those studies were neither intended nor sufficient to meet MSHA's broader research objective. Rather, the scope of those studies was to evaluate the effectiveness of control technology that both MSHA and the mine operator agreed were applicable to that one particular longwall MMU. The objective of the cooperative research program that MSHA and the Bureau of Mines were attempting to conduct, was to establish the combined efficiency of the various control technologies that the Bureau of Mines had developed through their ongoing dust control research program. However, even though no such study has been conducted, based on our experience, MSHA's position remains that feasible engineering or environmental controls exist for maintaining dust exposures at or below the applicable dust standard, for most, if not at all longwall operations. MSHA believes that the plan verification provision contained in this proposed rule will foster further improvements in the design and quality of mine ventilation plans for longwall MMUs. 4. Respiratory Protection While the Mine Act provides that operators “make available” approved respirators to miners during periods of noncompliance, when miners may be overexposed, the Act specifically prohibits using such devices as a substitute for environmental controls in the active workings of the mine. As previously discussed elsewhere in the preamble, this is because environmental or engineering controls are reliable, provide consistent levels of protection to large number of miners, allow for predictable performance levels, can be monitored continually and inexpensively, and can remove harmful levels of respirable coal mine dust from the workplace. MSHA recognizes that approved respirators, such as the powered air-purifying type ( e.g., Racal® Airstream helmet or air helmet), 6 can be effectively used as an interim method of protecting miners from respirable dust hazards when properly selected, used, and maintained. Although a respirator may achieve satisfactory air quality in the miner's breathing zone when used in a good respirator program, their use will not achieve the intent of the Act, which is to control the level of respirable coal mine dust in the mine atmosphere in the active workings at or below specific limits. Accordingly, consistent with the intent of the Act and general industrial hygiene practice, it has been MSHA's long-established practice to rely on the strict adherence to a hierarchy of controls that prefers engineering controls over dependence on supplementary control measures ( e.g., respirators, work practices or both) to achieve compliance with the applicable dust standard. Nevertheless, the mining industry has urged MSHA over the years to accept the use of powered air-purifying respirators (PAPRs) or air helmets as an alternative method of complying with the applicable dust standard when engineering controls did not adequately control respirable exposure or were not feasible. Most recently, Energy West Mining Company (Energy West) petitioned the Secretary of Labor: 6 References to specific equipment, trade names or manufacturers does not imply endorsement by MSHA. [t]o amend the mandatory health standards for underground coal mines contained in the Secretary's regulations at 30 CFR part 70 in order to allow the use of airstream helmets or other types of powered air-purifying respirators (PAPRs) approved by the National Institute for Occupational Safety and Health (NIOSH) as a supplemental means of compliance with the respirable dust standards of subpart B of part 70. (Energy West, September 1997). Energy West contended that PAPRs are necessary as a supplemental means of controlling respirable dust because even the most diligent application of feasible engineering or environmental controls could not always prevent overexposure. This proposed rule responds to Energy West's petition for rulemaking. Although, as stated above and elsewhere in the preamble, the Agency does not believe that supplementary controls are as effective or as safe as engineering controls, MSHA believes, on balance, that under certain circumstances reliance upon the limited use of such measures is appropriate. Accordingly, MSHA is proposing to permit the limited use of either approved PAPRs, administrative controls, or a combination of both, for compliance purposes, in those circumstances where further reduction of dust levels cannot be reasonably achieved using all feasible engineering controls. In these situations, the burden of proof of infeasibility is appropriately placed on the operator. Also, as provided for under proposed § 70.212, MSHA recognizes that the use of PAPRs as a supplementary control may be appropriate on an intermittent basis when unusual operating conditions are encountered that adversely impact the ability of the previously verified plan parameters to effectively control respirable dust under prevailing conditions. MSHA will permit the use of PAPRs for a period not exceeding 30 calendar days if the operator demonstrates that the particular circumstances that necessitate the use of PAPRs occur only intermittently and are beyond the control of the operator. While the conditions under which MSHA would permit supplementary controls to be used introduces an added element of complexity to the proposed standard, the Agency believes that it will provide operators the flexibility to select the most appropriate option for supplementing the engineering controls which best meet the needs of the miners under the prevailing operating conditions. MSHA believes that the use of these supplementary control measures, under the conditions of use set forth in the proposed rule, will enhance the level of health protection for miners by preventing overexposures on all shifts when engineering controls cannot achieve the necessary reduction to or below the applicable dust standard. The combination of engineering and supplementary controls will provide reliable and effective exposure control when used in accordance with the approved plan provisions. This proposed rule, which provides for expanded use of supplementary controls under limited circumstances to protect individual miners, is not a departure from the Agency's long-standing practice of relying on engineering controls to achieve compliance, since these measures would not be used as a substitute or replacement for engineering control measures in the active workings. Rather, it is a recognition that, in those limited instances where supplementary controls may be used, engineering controls alone may not protect some miners from overexposure. a. Selection of Respirators: Powered Air-Purifying Respirators (PAPR) By choice, underground coal miners wear various styles of respirators to protect themselves from exposure to respirable coal mine dust including: disposable filtering facepieces, tight-fitting elastomeric masks, and PAPRs. Currently, over 50 percent of the operating longwall mines have miners who have chosen to wear PAPRs (MSHA, Longwall Summary, January, 1999) for added protection. The Racal® Airstream, or air helmet as referred to by miners, is a type of loose-fitting PAPR which has long been the respirator of choice in underground coal mines. Due to the weight of the device, its use has generally been limited to mines with coal seam heights exceeding six feet. The functional and physical characteristics of air helmets, as described below, make them especially well-suited to underground coal mining conditions. Accordingly, MSHA has chosen PAPRs as the type of respirator to be used when such devices are approved under this proposed rule. The air helmet has been in use in underground coal mines since the late 1970s. Developed primarily for mining use by the Safety in Mines Research Establishment (SMRE) in England, this respirator combines face, head, and respiratory protection in a single convenient unit. The support hardware, which provides the filtered air, is enclosed within the air helmet. Power for the system is provided by a belt-mounted battery. Mine air enters the helmet through a rear entrance port, passes through a pre-filter assembly that removes the coarse material, and then passes through the fan and into a final-filter assembly that is located between the head of the wearer and the outer helmet shield. The filtered air then sweeps down across the wearer's face, behind the face-shield visor, imposing minimal breathing resistance, and exits at the chin. A partial seal between the visor (inlet covering) and the face is accomplished using a flexible medium which contours to the wearer's neck and face. The original air helmet has undergone numerous design improvements since it was first introduced in British coal mines. The unit is now produced by the Minnesota Mining and Manufacturing Company (3M) (3M TM Helmet-Mounted Airstream TM series). Unlike other styles of PAPRs ( e.g. , hoods) and negative pressure, tight-fitting respirators, the air helmet is better able to provide various types of required personal protective equipment in an efficient package. For example, in addition to protecting the lungs, the helmet and visor (the inlet covering) of a PAPR can simultaneously protect the face and head from high-velocity nuisance dust, spray, and small pieces of coal from the cutting drums and face. PAPRs do not require fit-testing, unlike tight-fitting respirators. By definition, for PAPRs to be approved for use under this proposed rule, the visor must form a partial seal with the face, limiting entry of unfiltered mine air. Because this style of respirator does not have a tight-fitting facepiece, miners are not required to be clean shaven in order to wear this respirator correctly. MSHA's allowance of facial hair with this style of PAPR is also consistent with the Occupational Safety and Health Administration's (OSHA) regulation that facial hair prohibition applies only to tight-fitting respirators (29 CFR 1910.134 (g)(1)(i)(A) as discussed in 63 FR 1152). MSHA recognizes that there may be facial conditions which may prevent the proper fit of a PAPR. However, a well-designed respirator protection program should identify and address any extreme facial conditions, including excessive facial hair, which prevent the partial seal of the inlet covering and the face as intended, and thereby compromise the efficacy of the PAPR. For example, a miner could have exceptionally bushy sideburns which prevent the inlet covering from forming an appropriate partial seal with the face, and leave a significant gap between the inlet covering (visor) and chin. This situation would have to be rectified in order for the PAPR to be worn properly. Greenough (1978) summarized limitations of other styles of respirators as follows: [T]he objections to conventional face-mask respirators arise primarily from the mask being clamped to the wearer's face, often causing irritation and soreness: also the breathing resistance, though small, can affect the wearer's capacity to work over long periods (Johnson, 1976). Speech is impeded and if the respirator harness fits under the wearer's safety helmet it is necessary to remove the helmet when replacing the respirator. Greenough's description illustrates how other styles of respirators are less compatible with the other safety requirements for miners, as well as miners' comfort, and their need to communicate. It would be more difficult for a miner to perform his/her job effectively and communicate with fellow workers, wearing a tight-fitting respirator their entire work shift. Voice transmission through a tight-fitting respirator can be difficult, annoying and fatiguing. In addition, movement of the jaw in speaking can cause leakage, thereby reducing the efficiency of the respirator and decreasing the protection afforded the wearer. While voice communication is somewhat easier with a PAPR than with other respirator styles, the face shield is generally raised to communicate. Also skin irritation can result from wearing a tight-fitting respirator in hot, humid conditions. Tight-fitting respirators have straps which go across the crown and back of a miner's head which is under a miner's helmet ( i.e. , hard hat). Because miners are required to wear hard hats at all times while in the mine (30 CFR 75.1720(d)), each time a miner needs to break the seal of a tight-fitting respirator, to eat, or to speak, or to relieve the discomfort of the seal, he/she would have to remove the hard hat. Similarly, each time a miner would need to put a tight-fitting respirator back on he/she would have to remove their hard hat. It should be noted that both tight-fitting elastomeric respirators and disposable facepieces, if worn correctly, would require the wearer to be clean shaven. A large proportion of miners have a tendency to wear facial hair, especially during the fall and winter season. The unique qualities of the PAPR identified within this proposed rule are such that it could fall into either the helmet or loose-fitting facepiece categories. ANSI defines a loose-fitting PAPR with a helmet to be “a hood that offers head protection against impact and penetration (ANSI, 1988).” ANSI defines a loose-fitting PAPR with a loose-fitting facepiece as “A respirator inlet covering that is designed to form a partial seal with the face, does not cover the neck and shoulders, and may offer head protection against impact and penetration ( Ibid. ).” In this proposed rule, a powered air-purifying respirator (PAPR) is defined as an air-purifying respirator that uses a blower to force ambient air through the air-purifying elements to the inlet covering, which provides a partial seal with the face. This respirator must be approved by NIOSH under 42 CFR part 84 and by MSHA under 30 CFR 18 and offer head and face protection in compliance with 30 CFR 75.1720(a)and(d). A current list of equipment, including PAPRs, approved under 30 CFR 18 can be obtained from MSHA's Approval and Certification Center on the internet at http://www.msha.gov/TECHSUPP/ACC/lists/18instrm.pdf. A searchable index of approved respirators is available from NIOSH at http://www2.cdc.gov/drds/cel/cel_form.asp. As of 2002, the 3M Airstream Air-Purifying Helmet (MSHA Approval 2G-3143, originally issued to Racal 3/29/1979), was the only approved PAPR model suitable for use under this proposed rule. b. PAPR Protection Program In an underground coal mine, the degree of respiratory protection that a properly functioning PAPR will provide the wearer is a function of the type and condition of the air-purifying medium used to filter out the respirable dust particles from the mine air, the workplace environment ( i.e. , nature and concentration of the respirable coal mine dust), the work activity of the wearer in that environment, how the wearer uses the device ( i.e. , how often is the visor raised during the shift), and the care and maintenance of the PAPR's functional components and power source. These parameters are required to be addressed in the approved PAPR protection program (see example in Appendix B). In 1998, to increase the efficiency of the filtering medium used in PAPRs, NIOSH began requiring PAPRs to be equipped with a high efficiency particulate air (HEPA) filter. This change introduced a denser medium to filter the air, providing an extra margin of safety at all levels of respirable coal mine and quartz dust exposure. However, as a result of this change, the PAPR's average airflow dropped from about 9 cubic feet per minute (cfm) to 7 (cfm). While the current airflow still exceeds the required minimum airflow of 6 cfm (42 CFR 84.1152(b)), the drop in airflow reduced the level of comfort the PAPR provides to the miner. MSHA realizes that miners' comfort with a particular respirator is an important determinant to miners' proper use of it. Several previous commenters testified that PAPRs were not being used as approved. 7 Many of these examples related to reports that visors were fogging. These commenters attributed the fogging problem to NIOSH's recent (mid-1998) improvement in the filtering medium for PAPRs. One commenter testified: 7 NIOSH requirements for PAPR performance, including airflow are specified in 42 CFR subpart kk. Although § 84.1136 specifies that facepieces, hoods, and helmets shall be designed and constructed to provide adequate vision which is not distorted by the eyepiece, NIOSH does not have requirements for a visor's predisposition to fogging. I would have to answer honestly and say they [PAPRs] are being used in a modified condition. Miners some, you know, have typically removed the shroud * * * [miners] raise the face piece to communicate and so on * * *. We've had that [fogging of the visor] problem recently, * * * since we've been required [by NIOSH] to use the new version of the filter [the HEPA filter]. There has been what seems to be reduced flow in the unit and that has also resulted in more fogging. And we've worked real hard to try to—[work] with 3-M to try to resolve that. MSHA's experience has shown that fogging of PAPRs has been an intermittent problem since the introduction of PAPRs in underground mines. This is due to the inclement conditions of underground mining such as: High humidity, fluctuation in temperature, and physical exertion by miners. Some miners indicated that they had to replace the HEPA filters with socks to increase the PAPR airflow. Using socks in lieu of required filters is unacceptable. This one example of PAPRs being used outside the manufacturer's recommendations and the requirements of an approved respiratory protection program. Various approved remedies are available to control fogging of visors including: intermittent wiping down of the visor, “anti-fogging” visors, application of anti-fogging sprays, and the use of a new visor design with an anti-fog impregnate baked directly into the visor. A properly functioning respiratory protection program would address this issue, with respect to the appropriate selection and maintenance of a respirator. MSHA recognizes that for a PAPR protection program to be effective, the miner must be properly trained to wear the respirator, to know why the respirator is needed, and to understand the limitations of the respirator. Appendix B contains a model PAPR protection program to assist an operator in developing a mine-specific program in accordance with the provisions of the American National Standards Institute's “Practices for Respiratory Protection ANSI Z88.2-1969” as required by 30 CFR 72.710. Additionally, mine management must regularly conduct reviews to ensure continued effectiveness of the PAPR protection program. Under this proposed rule an operator will not be permitted to use PAPRs as a supplementary control without an MSHA approved respiratory protection program which meets the requirements of § 72.710 and incorporates the information required by proposed § 70.210(a)(2). c. PAPR Protection Factor The degree of workplace respiratory protection provided to the wearer by a properly functioning PAPR when correctly worn and used depends on the unit's ability to prevent the contaminant from entering the wearer's breathing zone. In general, the protection factor (PF) expresses PAPR performance as the ratio of the respirable dust concentration outside the respirator facepiece to the concentration inside the facepiece. It reflects the effectiveness of a respirator used in conjunction with a good respirator protection program. For example, a PF of 4 means that the particular respirator will reduce the concentration of respirable dust actually breathed to one forth of the concentration outside the respirator. In terms of worker health, there are various forms of the PF. One form is the assigned protection factor (APF). Terry Spear, et al. , 2000, defined an APF as follows: APF is a special application of the general protection factor concept, defined as a measure of the minimum nominal anticipated workplace level of respiratory protection that would be provided by a properly functioning respirator or class of respirators to a high percentage (usually 95% or more) of properly fitted and trained users * * *. The maximum specified use concentration for a respirator is generally determined by multiplying the exposure limit for the contaminant by the protection factor assigned to a specific class of respirator. In the NIOSH Respirator Decision Logic (May 1987), based on simulated laboratory tests and some workplace protection tests (none of which replicated conditions in underground coal mines), NIOSH assigned, helmeted PAPRs, properly worn, a protection factor (APF) of 25. NIOSH made the following cautionary statement: Despite the fact that some of the PF's [APFs] have a statistical basis, they are still only estimates of the approximate level of protection. It must not be assumed that the numerical values of the APF's presented in this decision logic represent the absolute minimum level of protection that would be achieved for all workers in all jobs against all respiratory hazards. The industrial hygienist or other professional responsible for providing respiratory protection or evaluating respiratory protection programs is therefore encouraged to evaluate as accurately as possible the actual protection being provided by the respirator (NIOSH, May 1987). Furthermore, in its Guide to Industrial Respiratory Protection (September 1987), published after the NIOSH Respirator Decision Logic, NIOSH offered an additional caution with regard to the effectiveness of PAPRs: Until recently, powered air-purifying respirators were considered positive pressure devices. Field studies by NIOSH as well as others, have indicated that these devices are not positive pressure, and that their assigned protection factors are inappropriately high. (NIOSH, September 1987). There is virtually no positive pressure in the PAPR. Respirable dust may enter the miners' breathing zone through openings along the side and bottom of the visor, even when it is in the full lowered position. The extent to which respirable dust enters a miner's breathing zone, depends, in part, on the velocity of air provided to the MMU and on the miner's work rate and his or her angle of orientation to the airflow. NIOSH recommended in their 1987 Respirator Decision Logic an APF of 25 for all loose-fitting hood or helmet PAPRs. However, the environmental conditions assumed in NIOSH's estimation of an APF for PAPRs are not consistent with those in underground longwall mining operations, where high air velocities for methane and dust control are common. Other, unique conditions of coal mining (obstructed views and difficulty communicating) will compel miners to lift their visors. Once the visor is raised, the respirator is no longer being worn in accordance with conditions required for an APF of 25. The actual fit or seal of the respirator helmet to the wearer, repeated work-task motions in confined work spaces, raising the visor, and high air velocities along the longwall face all may significantly reduce the actual degree of respiratory protection provided in the workplace. Therefore, it is imperative that such factors be taken into account when estimating the degree of workplace respiratory protection a PAPR provides to the wearer. According to Spear (2000) a workplace protection factor (WPF) is: [a] measure of the actual protection provided in the workplace under conditions of that work [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A03-3941. Public record. Not legal advice.