Field performance measurements of half-facepiece respirators: developing probability estimates to evaluate the adequacy of an APF of 10.
Am Ind Hyg Assoc J 1998 Nov, 59(11):796-801
To evaluate the protection provided by negative-pressure, half-facepiece respirators, ambient and in-facepiece samples were collected on workers in foundry, aircraft-painting, and steel-manufacturing operations. Protection was assessed by workplace protection factors (WPF). The appropriateness of the assigned protection factor (APF) for half-facepiece respirators was evaluated with a new approach using the WPF data from these and other studies previously published. The new approach utilizes binomial statistics based on the number of successes (no overexposure) and failures (overexposure) and is illustrated with a graphical representation of WPF data. With this consideration of the data, the probability of overexposure occurring during a wearing period for workers wearing the half-facepiece respirators represented by the studies referenced here was 0.5%, with a 95% confidence interval of 0.01 to 2.7%. If 50% in-facepiece sampling errors are considered, the probability of overexposure was 2.9%, with a 95% confidence interval of 1.1 to 6.3%. The authors believe the current APF of 10 for half-facepiece respirators is appropriate.
Respirable-dust; Respiration; Respirators; Dust-exposure; Dust-particles; Dusts; Face-masks; Personal-protection; Personal-protective-equipment; Dust-sampling; Sampling-methods
U.S. Department of Health and Human Services, Public Health Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Health Effects Laboratory Division, 1095 Willowdale Road, Morgantown, WV 26505
American Industrial Hygiene Association Journal