Understanding the Breathing Gas Capacities (Ratings) of Escape Respirators for Mineworker Use.

摘要

The following information will help workers understand the meaning of breathing gas capacity of a jointly approved National Institute for Occupational Safety and Health (NIOSH) and Mine Safety and Health Administration (MSHA) closed-circuit escape respirator (CCER). Understanding the uses and limitations of the CCER is important in planning for an escape during a mine emergency. CCERs are known in the mining industry as self-contained self-rescuers (SCSR). All closed-circuit escape respirators contain a fixed quantity of oxygen. The new NIOSH/MSHA CCER standards upgraded the performance and design requirements of this type of respirator and established an oxygen capacity level for each CCER so that a purchaser can know how much oxygen it contains. Under the old standard, CCERs were rated and labeled by duration specified in time intervals. It did not indicate the volume of oxygen that the CCER contained. The rated duration can be very misleading because the amount of oxygen needed to complete a successful escape varies both for each person and for each escape scenario.