Estimated workplace protection factors for positive-pressure self-contained breathing apparatus.
Campbell-DL; Noonan-GP; Merinar-TR; Stobbe-JA
Am Ind Hyg Assoc J 1994 Apr; 55(4):322-329
An analytical model was developed for determining the effect of momentary negative excursions in facepiece pressure on workplace protection factors. The model was able to characterize the performance of a wide variety of positive pressure respirators. The performance of positive pressure self contained breathing apparatus (SCBA) was estimated with this model. The results were consistent with the high assigned protection factor (APF) currently established. A total of 57 measurements were taken of facepiece pressure in an earlier NIOSH field study (Firesmoke) of firefighters engaged in active firefighting and applied to this investigation. During this earlier study there were four donnings in which facepiece pressure momentarily went negative one or more times during use. The theory was that the performance of a positive pressure SCBA can be determined relative to the performance of a negative pressure respirator with the same facepiece, either a negative pressure SCBA or a negative pressure air purifying respirator. Results were consistent with the current NIOSH APF for a positive pressure SCBA.
NIOSH-Author; Personal-protective-equipment; Face-masks; Respiratory-protection; Analytical-models; Respiratory-protective-equipment; Equipment-reliability
American Industrial Hygiene Association Journal