America's Mine Safety and Health Administration (MSHA) has proposed a new law governing the exposure of all underground miners to diesel particulate matter (DPM).

The US Department of Labour officially gave notice of the plan in the Federal Register on Thursday (August 14th).

The proposal forms part of an agreement forged after the MSHA's existing DPM regulations were legally challenged.

Under the terms of the new agreement, a permissible exposure limit would be installed and would be measured in a different fashion than previously in order to improve accuracy.

The proposal would also seek to ensure such changes were enforceable, with new strategies being devised for a DPM control plan.

In particular, MSHA would be allowed to consider economic and technological feasibility in determining if mine operators qualify for an extension of time in which to meet the DPM limits.

The consultation period closes on October 14, 2003.