Comparison of respirator fit test methods with an actual measurement of exposure.
Coffey-C; Campbell-D; Myers-W; Das-S
American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas. Fairfax, VA: American Industrial Hygiene Association, 1997 May; :13-14
Quantitative fit-tests (QFT) have been assumed to be predictive of the protection respirators would provide a wearer in his workplace. Workplace studies have consistently found no correlation between quantitative fit factors and workplace protection factors. This study was undertaken to correlate six QFT methods under laboratory conditions against exposure to 1,1,2 trichloro-1,2,2 trifluoroethane (FreonŽ) assessed by exhaled breath analysis. The six QFT method protocols were based on using either corn oil or ambient aerosol or controlled negative pressure. Respirators used in the study were both disposable and elastomeric organic vapor/high efficiency half masks. The exhaled breath of subjects exposed to 0.5, 3, 5, 25, 50 and 100 ppm-minutes of Freon was evaluated at 30 minutes postexposure. This characterization was then used to predict the actual exposure to Freon during correlation testing. Fit factors resulting from the QFT protocols were then individually correlated with the protection determined from these predicted Freon exposures using the coefficient of determination, R2. The QFT methods were 1) low flow, flush probe (CLF); 2) high flow, deep probe (CHD); 3) exhalation valve discharge (EVD); 4) controlled negative pressure (CNP); 5) ambient aerosol 1-10 minutes, 6 exercises (AAI); and 6) ambient aerosol 2- 30 minutes, 17 exercises (AA2). The lowest R2 value, 0.187, was found with the EVD method. The highest R2 values, 0.788 and 0.774, were associated with respectively the CHD and AAI methods. The results of this study suggest that some QFT methods can be predicative of actual respirator performance.
Respirators; Respiratory-equipment; Respiratory-protective-equipment; Respiratory-protection; Workers; Work-areas; Laboratory-testing; Exposure-levels; Exposure-limits; Face-masks
American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas