Frustrated by rulemaking foot-dragging on the part of the Obama administration, West Virginia Senator Jay Rockefeller (D) has introduced a bill that would impose a deadline on the Mine Safety and Health Administration (MSHA) for finalizing a proposal to reduce respirable dust limits in mines.

The legislation is intended to combat the rise in black lung disease, an irreversible and potentially fatal pulmonary disease caused by the inhalation of coal dust. After passage of the 1959 coal mine safety law, black lung disease rates declined. However in recent decades the rates have rebounded. Researchers are raising alarms over the fact that increasingly, younger miners (with fewer years of occupational exposure) are getting diagnosed with the disease – and with a particularly aggressive form of it.

Media reports have documented widespread cheating on coal dust controls by coal mine operators.

Rockefeller’s Black Lung Health Improvement Act of 2013 does not require a specific new coal dust limit, but gives MSHA six months to set one. The agency was supposed to have a proposal finalized by September but it has indicated that it will not meet that timeline. The legislation does say the final rule must lower the legal exposure levels “in order to provide the maximum feasible protection” for miners.

According to the National Institute for Occupational Safety and Health (NIOSH), approximately 10,000 coal miners died in the U.S. from black lung disease from 1996-2005.