It is required that a self-rescue device be provided and available for each worker underground. Neither does the device provide protection against toxic gases other than carbon monoxide. The filter self-rescue device must be carried on the worker, attached to the mobile equipment the worker is operating, or located within 25 feet of the worker, so that it will be readily available in case of an emergency. The operator has the responsibility of training workers in the use of filter self-rescue devices, and also of setting up and carrying out a maintenance program for the devices. The maintenance program should include both visual inspection and weighing.
Weight gain indicates leakage and absorption of moisture.
Each device should be weighed upon receipt from the vendor and at regular intervals thereafter. The current weight is compared with the manufacture's weight stamped on the case. A weight record should be kept for each device. In addition to regular weighing, the miner should know how to inspect the device and report defects such as a damaged case, a broken seal, or any sign that leakage has occurred. Defective devices should be removed from service immediately.