By Avi Meyerstein

Coal mine operators following MSHA’s regulatory agenda are keeping their eyes on coal dust rulemaking these days. MSHA is paving the way for new sampling technology and methods, with the agency feeling the ever-present pressure to adopt a more stringent coal dust exposure limit.

MSHA recently announced that it will hold a hearing on July 8 in Arlington, Va., on its proposal to establish criteria that would be compatible with a new dust monitoring device. Since 1972, MSHA regulations have provided that mine operators use the MSHA- and NIOSH-approved coal mine dust personal sampler unit (CMDPSU) to sample mines to determine compliance with the MSHA coal dust exposure limit of 2 mg/m3. The current CMDPSU samples dust collected over an eight-hour shift on cassettes. The cassettes are then sent for an analysis that can take two weeks. By the time results come in, they provide only a look back at what mine conditions were during an entire shift, but do not provide immediate feedback or identify which areas a miner visited during that shift that may have had problematic dust levels.

For years, a coalition of MSHA, NIOSH, labor, industry, and a private technology firm have worked together on a better sampling technology, which MSHA is preparing to debut. The new ‘‘continuous personal dust monitor’’ (CPDM) would be worn by miners to provide real-time dust exposure levels as they happen, as well as end-of-shift summaries. According to MSHA, a pre-commercial unit passed extensive testing in 2006. However, MSHA’s current regulations are specific to the CMDPSU, so in January of this year MSHA proposed to change the rules to make way for the new CPDM.

Under the proposed rule, the new CPDM would have to provide legible results via an illuminated digital display and be adequately audible, record results in a format compatible with “widely available computer technology,” and report results in mg/m3. The device would need to have enough power to sample for 12 hours in an environment with up to two times the allowable dust limit. The device must have safeguards against tampering, withstand electromagnetic interference, and accurately measure respirable coal dust ranging from 10% of the permissible exposure limit (PEL) to two times the limit.

Other than signaling that the new CPDM is closer to becoming a reality, the current rulemaking does little to resolve a debate that has been ongoing for years about how to measure coal dust exposure. Even though MSHA is now working on setting the technical requirements for the sampling device, it has not even broached some of the more difficult subjects. MSHA emphasizes that “[t]his rulemaking is limited to approval requirements and does not address requirements concerning how sampling devices must be used to determine compliance, e.g., who, when, and how often to sample.” Yet, without addressing these issues, the rule raises more questions than it answers.

MSHA insists that current usage requirements still apply, but once the new CPDM debuts, will they change? How will the CPDM be used? Is it accurate enough to accomplish its goals? Who will monitor and report readings? With a continuous stream of information on exposure levels, will mines be shut down immediately upon obtaining certain readings?

All of the stakeholders appear to support having the kind of actionable, real-time data that the new CPDM promises to provide. But, there are likely to be important differences among them regarding how to use this data.

For one, MSHA’s regulatory agenda now indicates that it intends to continue its frustrated efforts at rulemaking to adopt single-shift sampling of coal dust exposures (replacing using an average of samples taken during multiple shifts). In 1972, MSHA and NIOSH had found that single-shift sampling would not work because it “would not, after applying valid statistical techniques, accurately represent the atmospheric conditions to which the miner is continuously exposed.”

Industry has argued that with a chronic disease resulting from cumulative lifetime exposure to dust, a snapshot measurement of one location over one shift does not accurately reflect worker exposure during a career. They argued that with single-sample measurements, operators would have to reduce overall dust levels to just a fraction of the actual PEL to ensure that any single sample would not exceed the limit–effectively changing the limit without doing so explicitly. And, they said, MSHA’s single sample method has an unacceptable error rate and fails to account for variability within mines.

When MSHA and NIOSH tried to reverse their own 1972 rejection of single-shift samples, in the 1990s, the U.S. Court of Appeals for the Eleventh Circuit vacated the new rule as not feasible.  In 2003, the agencies began a rulemaking on single-shift samples again. That rulemaking has been held open for comments ever since. MSHA now says it will issue a notice soliciting additional comments in October. Will MSHA try to impose single-shift samples before introduction of the CPDM? MSHA’s current dust monitor rulemaking also revises the requirements for the current dust monitor, suggesting those devices will still continue in use for at least some time. Will single-shift sampling apply even with those older devices?

All of these issues do not even get to the elephant in the room—the level of coal dust exposure that should be permitted, currently 2 mg/m3. MSHA’s regulatory agenda now says that the agency will issue a notice of proposed rulemaking in April 2011 to reduce the limit, but the pressure is on. In 1995, NIOSH recommended cutting the limit in half, to 1 mg/m3, and since then, an advisory committee also recommended a lower limit. Last year, a Kentucky coal miner sued MSHA to try to force a new limit, and labor believes 2011 is not soon enough for a new limit.

For the moment, MSHA appears intent on withstanding this pressure to reduce the limit immediately, focusing first on what may feel like an easier issue–introduction of the widely-supported new dust monitors. It won’t be long, though, before even that issue presents sticky questions that MSHA has yet to resolve.

Meyerstein is an associate with Patton Boggs LLP. He can be reached at 202-457-6623 or by E-mail at ameyerstein@pattonboggs.com.