Recent experimental studies on the wearing of filter self-rescuers

In wearing trials, subjects wore filter self-rescuers (FSRs) for periods of 60 minutes while walking on a treadmill in ambient conditions ranging from 20-29 C dry bulb and from 15-24 C wet bulb, and while exercising in a training gallery under similar environmental conditions. In hot inspired air trials, subjects walking on the treadmill were supplied with dry air heated to a temperature chosen to simulate the inhaled air temperature reached in an FSR worn in an atmosphere containing carbon monoxide. The trials showed that men can satisfactorily tolerate wearing an FSR, under the conditions imposed, for 60 minutes. Comments on the discomfort of the head harness led to the development of a new one, which was found to be more acceptable in every respect.