Effects of Temperature and Humidity on Respirator Fit Under Simulated Work Conditions.

摘要

A study conducted at the Los Alamos National Laboratory compared quantitative fit factors and simulated work factors and determined the effects of temperature and humidity on respirator fit. The study used a commercially available fit chamber and an environmental chamber set at six conditions to simulate U.S. work environments. Seven respirators were tested on a limited test panel of 10 subjects. The test results indicate that the performance of one powered air-purifying respirator (PAPR) helmet is significantly degraded during the simulated work exercises, whereas the half-mask PAPR performance was not affected. Tight-fitting facepiece PAPRs provide higher protection than loose-fitting PAPRs. The performance of the negative-pressure half-mask and full-facepiece respirators is degraded during fit tests at high humidity and high temperature. The degradation of the fit factors for the negative-pressure half-mask during high humidity at ambient and high temperatures is probably due to facepiece slippage caused by sweating. More dynamic exercises, including motions in which the individual bends over and stands up repeatedly, are recommended to develop quantitative fit factors that adequately simulate work factors.