This program protection factor study was conducted to evaluate the effectiveness of filter cartridge respirators while coke oven workers performed their normal work. Benzene soluble fraction (BSF) of total particulate concentrations was measured inside and outside the respirators of nine coke oven workers who worked on the top of the battery of one older coke oven plant and who reported regular use of respirators. The measurements were taken for 3 consecutive days. Excluding two undetectable measurements inside the respirator, it was found that the outside respirator BSF concentrations (25 sets) ranged from 87 to 807 mug/m(3), whereas the inside respirator BSF concentrations ranged from 16 to 509 mug/m(3). A program protection factor (PPF) for each set of observations was calculated as the ratio of outside to inside air BSF concentrations. The mean PPF was 2.5 with a range of 1.1 to 9.6, and 12 of the 25 measurements (48%) were below 2.0. Although the workers claimed they regularly wore their respirators, the wide range and the low PPF findings suggest that worker behavior and respirator fit may influence the level of protection provided by the respirator.
