[Fit test evaluation of three half mask respirators for workers exposed to organic solvents]

Objective: To assess the appropriateness of half mask respirators for organic solvent-exposed workers and the influencing factors. Methods: In January 2025, 113 workers exposed to organic solvents were selected as the research subjects using a convenient sampling method. The general information of the workers was investigated. A handheld 3D scanner was used to measure 16 head-face dimensions of the workers, including head length and morphological face length. Then, the quantitative fit test instrument TSI Porta Count Pro(+) 8038/8048 was used to conduct quantitative fit tests on the 3100, 3200, and 3600 half mask respirators worn by the workers. The Chi-square test was used to analyze the differences in the pass rates of the fit tests for each model of half mask respirators, and binary logistic regression was used to analyze the factors influencing the test results. Results: The overall pass rate of quantitative fit test for the three half mask respirators models for workers exposed to organic solvents was 77.9% (264/339). The pass rates for Model 3100, Model 3200, and Model 3600 half mask respirators were 84.1% (95/113), 74.3% (84/113), and 75.2% (85/113), respectively. There was no statistically significant difference in the pass rates of the fit tests for the three models (χ(2)=3.80, P>0.05). The four test actions of bending over, speaking loudly, turning the head left and right, and raising and lowering the head in the fit test had no statistically significant influence on the pass rate (P>0.05). Binary logistic regression analysis showed that the pass rate of Model 3100 was negatively correlated with head length and morphological face length of the workers exposed to organic solvents (P<0.05) ; the pass rates of Model 3200 and Model 3600 for female workers were lower than those of male workers (P<0.05) . Conclusion: The pass rates of the fit tests for the three half mask respirators for workers exposed to organic solvents are all relatively high. Head length, morphological face length, and gender are factors affecting the fit test of the half mask respirators.