The U.S. Department of Labor's Mine Safety and Health Administration announced in a recent press release that today theFederal Registeris expected to publish an emergency temporary standard that revises the existing federal standard on maintenance of incombustible content of rock dust. The determination to create an ETS was based on MSHA's review of accident investigation reports of mine explosions in intake air courses that involved coal dust, as well as the National Institute for Occupational Safety and Health’s report “Recommendations for a New Rock Dusting Standard to Prevent Coal Dust Explosions in Intake Airways,” which can be viewed at .

"Coal dust can cause explosions, and explosions kill miners. Inadequate rock dusting can dramatically increase the potential for a coal mine explosion," said Secretary of Labor Hilda L. Solis. "Compliance with the new standard will strengthen the protection for miners by minimizing the potential for such an explosion and, ultimately, will save lives."

The ETS, effective immediately, applies only to underground bituminous coal mines and can be viewed in the "special filings" section of theFederal Register's website at Emergency Temporary Standards take effect immediately when evidence is presented that workers are in grave danger. They remain in effect until a standard is promulgated through the regular rulemaking process.

In addition to the ETS, MSHA is also issuing a program information bulletin, which provides guidance on compliance with the new standard. The bulletin may be viewed on MSHA's website at

"Explosions caused by coal dust are particularly violent and deadly," noted Mine Safety and Health Administration Assistant Secretary Joe Main. "When the NIOSH report was released in May 2010 containing new scientific evidence that called for a higher standard, MSHA moved quickly to get this new standard in place. We also revised our guidance on rock dusting to ensure that mine operators are taking the steps necessary to provide for the safety of everyone working in their mines." The existing MSHA standard requires mine operators to maintain at least 80 percent total incombustible content of combined dusts in return air courses and at least 65 percent TIC in all other areas. It also requires that the percent TIC of combined dust in all areas where methane is present in any ventilating current be increased. The 80 percent TIC must be increased by 0.4 percent for each 0.1 percent of methane in return air courses, and the 65 percent TIC must be increased by one percent for each 0.1 percent of methane present in all other areas.

The ETS revises the existing standard by requiring mine operators to increase the total incombustible content of the combined coal dust, rock dust and other dust from 65 to 80 percent in all accessible areas of underground bituminous mines, and an additional 0.4 percent for each 0.1 percent of methane where methane is present in any ventilating current.

Although the ETS is effective on Sept. 23, mine operators will have additional time for compliance in order to purchase more rock dust-related materials and equipment. Mine operators must comply with the ETS for newly mined areas by Oct. 7, 2010, and all other areas of the mine by Nov. 22, 2010. To meet these compliance dates, MSHA encourages mine operators to immediately begin rock dusting all other areas, starting with those that pose the greatest risk to miners: for example, areas near the active faces and areas that contain possible ignition sources, such as conveyer belt drives and belt entries. "We know that it will take mine operators a little bit of time to bring their mines into compliance with the new standard," Main added. "But coal dust explosions are serious, and we expect mine operators to act quickly to reduce the threat to those mining coal underground."

For a video overview of the danger of un-neutralized coal dust in mines explosions, please visit:

SeeProgram Information Bulletin