The relationship between the filtering facepiece respirator fit and the facial anthropometric dimensions among Chinese people

Taking action in response to anthropometrics is important to respirator fit. We aimed to investigate the associations between the filtering facepiece respirator (FFR) fit and the head-face dimensions among Chinese people. We used data from 85 volunteers. We focused on fit factors and 8 head-facial dimensions of subjects. The fit factors from 4 respirator models with different protection levels and shapes were measured by a PortaCount fit tester. Each subject tested four respirator models, for a total of four quantitative fit tests per subject. Passing rate (PR) of each model was determined at fit factor level no less than 100. The data of 85 subjects aged 22-51 yr old were analyzed using χ² test, one-way ANOVA test, t-test and non-conditional logistic regression model. The PRs for the 4 models were 52.9%, 61.2%, 40.0% and 63.5%, which were significantly different. We found the positive effect of morphological facial length and negative effect of bitragion-submandibular arc on fit factors. This confirms it is necessary to conduct fit test before using a respirator. PRs varied among 4 models regardless of their protection level and shape. Anthropometric dimension of the user, which had effects on FFR fit, should be considered when designing respirator.