miner's self-rescuer

miner's self-rescuer

[′mīn·ərz ¦self ′res·kyü·ər]
(mining engineering)
A pocket gas mask effective against carbon monoxide; air passes through a cannister containing fused calcium chloride before entering the mouth.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.