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 Web site at

The existing MSHA standard requires mine operators to maintain at least 80% total incombustible content (TIC) of combined dusts in return air courses and at least 65% TIC in all other areas. It also requires the percent TIC of combined dust in all areas where methane is present in any ventilating current be increased.

The 80% TIC must be increased by 0.4% for each 0.1% of methane in return air courses, and the 65% TIC must be increased by 1% for each 0.1% of methane present in all other areas.

Mine operators must comply with the ETS for newly mined areas by October 7, 2010, and all other areas of the mine by November 22, 2010. To meet these compliance dates, MSHA encourages mine operators to immediately begin rock dusting, starting with those that pose the greatest risk to miners.