Causes of in-facepiece sampling bias - I. Half-facepiece respirators.
Myers-WR; Allender-JR; Iskander-W; Stanley-C
Ann Occup Hyg 1988; 32(3):345-359
A study of the causes of in facepiece sampling bias was presented. The test agent was acetone (67641) vapor. Three half facepiece respirators from commercial sources were tested. The sampling bias for the three respirators was significantly different. Factors which had a significant effect on sampling bias were leak site, breathing pattern, probe location, probe depth, and leak site breathing pattern interactions. With two of the facepieces tested, the best sampling occurred when the probe was opposite the mouth; this was the worst sampling site for the other facepiece tested. The geometry, circular or slit type leaks, were not found to have an effect on sampling. Neither multiple leaks nor differences in leak rates had an effect on in facepiece sampling. The authors recommend that respirator testing and interpretation of results be evaluated carefully.
NIOSH-Author; Respiratory-protection; Sampling-methods; Personal-protective-equipment; Respiratory-equipment; Air-sampling; Face-masks
Annals of Occupational Hygiene