Related Experiment Videos
Comparison of three commercially available fit-test methods.
Larry L Janssen1, D Michael Luinenburg, Haskell E Mullins
13M Occupational Health and Environmental Safety Division, 3M Center, Bldg. 0235-02-E-91, St. Paul, MN 55144-1000, USA.
Summary
Respirator fit-test performance varies significantly based on the reference method used for evaluation. Current fit-testing methods do not consistently meet American National Standards Institute sensitivity criteria, highlighting the need for standardized assessment.
Area of Science:
- Occupational Health and Safety
- Industrial Hygiene
- Respiratory Protection
Background:
- The American National Standards Institute (ANSI) standard Z88.10 provides criteria for evaluating respirator fit-tests.
- Quantitative fit-tests (generated aerosol, particle counting, controlled negative pressure) and qualitative fit-tests (bitter aerosol) are used to assess respirator fit.
- Occupational Safety and Health Administration (OSHA)-accepted methods are often validated against generated aerosol as a reference.
Purpose of the Study:
- To compare the comparability of three OSHA-accepted fit-test methods.
- To determine the effect of the reference method on the apparent performance of fit-test methods.
- To evaluate if current fit-test methods meet ANSI sensitivity criteria.
Main Methods:
- Sequential fit-tests were conducted using controlled negative pressure (CNP) and particle counting (PC) quantitative methods, and bitter aerosol (BA) qualitative method.
- Each method was used to perform 75 fit-tests.
- Sensitivity was calculated by comparing each method against the other two as reference methods.
Main Results:
- CNP identified 24 failures, BA identified 22 failures, and PC identified 15 failures out of 75 tests.
- None of the evaluated fit-test methods achieved an ANSI sensitivity criterion of 0.95 or greater when compared with other methods.
- The apparent performance of a fit-test method is dependent on the chosen reference method.
Conclusions:
- The choice of reference method significantly influences the perceived performance of respirator fit-test methods.
- The evaluated fit-test methods employ distinct criteria for identifying inadequate respirator fits.
- While absolute 'acceptable fit' remains undefined, existing methods show potential for rejecting poorly fitting respirators, as supported by workplace protection factor studies.