The NMA petitioned to eliminate the December 31 deadline requiring the replacement of certain refuge alternative components. The move was based on newly conducted yet unreleased research by the National Institute for Occupational Safety and Health (NIOSH) raising concerns about the effectiveness refuge alternatives of the existing fleet.

NIOSH’s findings on the heat and humidity, as well as purging capabilities of existing refuge units, prompted NMA’s petition that, if granted, would allow units to remain in service until all stakeholders can determine the best way to address NIOSH fears. The petition formalizes an earlier NMA request.