Abstract
This article presents the results of a workplace protection factor (WPF) study for half-facepiece respirators conducted in an aircraft paint-spraying operation. The major elements of the paint overspray collected with ambient samples were titanium, strontium, chromium, and silicon. The major elements collected on the in-facepiece samples were chlorine and silicon. The geometric mean (GM) ambient concentrations of chromium and titanium varied significantly among painting locations and paint types. There was a significant difference in GM in-facepiece concentrations of titanium among painting locations. However, no significant difference in GM in-facepiece concentrations of chromium by location was found. In both ambient and in-facepiece samples the amounts of chromium and strontium were highly correlated as expected. In ambient samples total airborne mass was highly correlated with levels of chromium and titanium when primer and top coat were applied, respectively. No difference in respirator performance, measured by in-facepiece concentration and WPF, was observed during the application of top coat. During the application of primer, Respirator 1 had a significantly higher GM in-facepiece concentration level of chromium and a correspondingly lower GM WPF value than Respirators 2 and 3. The 5th percentile estimates for all WPF data or different subsets of WPF data partitioned by paint type and respirator were much greater than 10. Measured WPF values and in-facepiece exposure levels were significantly correlated with an R2 of 0.55. When the half-facepiece respirators, equipped with high-efficiency/organic vapor combination air purifying elements, were conscientiously worn, used in conjunction with existing controls, and were properly maintained, they provided effective worker protection.