By Susan Kelly

April 22, 2019 - The Centers for Disease Control and Prevention (CDC) issued a final rule Thursday removing a deadline for device makers to discontinue the manufacture and sale of certain closed-circuit escape respirators.

The agency's National Institute for Occupational Safety and Health (NIOSH) determined the planned discontinuation was likely to result in a shortage of wearable large-capacity escape respirators for underground coal miners who rely on the devices in case of emergency.

CDC also clarified that post-approval testing of closed-circuit escape respirators would exclude human subject testing and environmental conditioning.

A closed-circuit escape respirator is an apparatus that allows the wearer to re-breathe exhaled air after the carbon dioxide has been removed and oxygen supply has been restored from a source within the device. The respirators are most often used for survival in industrial work settings during emergencies.

In the mining industry, the devices are called self-contained self-rescuers and are used by miners to escape dangerous atmospheres, whereas Navy and Coast Guard personnel working below deck on vessels, as well as workers in the railroad industry, refer to the apparatus as an emergency escape breathing device.

Standards for approval of closed-circuit escape respirators were updated in a final rule published in March 2012 that was intended to improve the performance, reliability and safety of the devices used in underground coal mining. The effort followed decades of reports from the field documenting user concerns about difficulty in checking damage to the devices in harsh environments and incidents in which users did not receive the expected duration of breathing air.

NIOSH sought to accelerate adoption of the enhanced standards, but manufacturers were unable to develop devices in time to meet a transition deadline, prompting several extensions of the deadline. Due to concern about a supply shortage, the latest deadline for companies to discontinue the manufacture and sale of the older-version closed-circuit escape respirators was removed.

The new final rule, effective May 20, permits continued manufacturing, labeling and sale of the older model closed-circuit escape circuit respirators indefinitely. The rule also clarifies that neither human subject testing nor environmental testing is required to be routinely conducted on respirators for a NIOSH evaluation program, when NIOSH deems the tests to be unnecessary.

CDC said NIOSH will continue to work with respirator manufacturers to ensure the uninterrupted supply of approved escape respirators.