Some observations on frequency of respirator fit tests.
Am Ind Hyg Assoc J 1984 Feb; 45(2):134-135
A study of the frequency of respirator fit testing necessary to detect respirator failure was conducted. The study was designed to test the null hypothesis that the results of failure tests over time would be random versus the alternative hypothesis that fit test failure rates would show either a positive or negative trend. Data were selected from the results of a continuing fit test program at a large industrial facility in which the MSA Ultra View, a fullface air purifying respirator, was used. A total of 11,086 fit tests were conducted using a test aerosol of dioctyl-phthalate. Adequate fit was defined as a measured penetration of 1.0 percent or less. The overall failure rate on initial testing was 1.8 percent. Of the individuals who passed the initial test, 1,968 were given a second respirator fit test 0 to at least 36 months later. The failure rates decreased with time, the highest failure rates 3.3 and 3.6 percent occurring within the first 6 and 12 months, respectively. After 30 months, failure rates were 0. The overall failure rate was 1.2 percent, which differed from the initial rate at a level of significance between 0.2 and 0.1. The authors conclude that the passage of time does not appear to result in increased respirator fit failure rates. Although the null hypothesis cannot be definitely rejected, the results suggest a trend toward decreasing fit test failure with time. Respirator wearers apparently obtain a better fit as time progresses. Further studies with larger populations are required to confirm these findings.
NIOSH-Publication; NIOSH-Grant; Personal-protection; Respiratory-protection; Worker-health; Control-methods; Respiratory-protective-equipment; Humans; Occupational-health
Environmental Health University of Washington Environmental Health Dept Seattle, Wash 98195
American Industrial Hygiene Association Journal
University of Washington, Seattle, Washington