America’s National Mining Association and several other industry associations and companies last week moved to block the implementation of three Mine Safety and Health Administration (MSHA) provisions that set arbitrary limits on the amount of total carbon (TC) emissions permissible in diesel exhaust in underground metal and non-metal mines. NMA is challenging the rules on the grounds that they lack adequate scientific justification and would cause irreparable harm to the industry. NMA also emphasized that MSHA, itself, has vacillated on whether the rules are actually feasible.

NMA filed an emergency motion with the US Court of Appeals for the District of Columbia Circuit on July 19 seeking a stay against the rules. The request for a stay also included a request that the court expeditiously consider challenges against the rules. NMA said a stay and expedited review are urgently needed as companies cannot feasibly comply with the rules.

The July 19 court filing argued that there is no evidence of any adverse health effects tied to MSHA’s proposed TC limits, but noted that despite this lack of evidence, MSHA’s proposed TC level would trigger new hazards by forcing widespread and unplanned exhaust control experiments and encourage disruptive workforce transfers and dislocations. NMA and its fellow petitioners also argued that the rules would force them to be in violation of infeasible exposure limits, resulting in increasingly severe sanctions and would injure business, growth and market opportunities.

NMA criticized MSHA for failing to regulate based on the latest research and data, including research conducted by the National Institute of Occupational Safety and Health (NIOSH). NMA noted that while other federal agencies regulate diesel exhaust gas, MSHA is the only one to do so by limiting the carbon content of such exhaust. In addition, NMA said the proposed rules for metal and non-metal underground mines make little sense given that MSHA protects miners in underground coal mines with an exhaust standard that does not cover carbon.

In addition, the request to stay noted that MSHA has gone back and forth on whether or not the TC rules are feasible, pointing to a 2005 agency determination that declared the rules, first drafted in 2001, as unworkable. NMA charged that MSHA’s attempt to implement the rules, some eight months after declaring them infeasible, “defies logic.”