If the mask fits: Facial dimensions and mask performance

Fit factor (FF) is a generally accepted metric to assess the facial fit of Respiratory Protective Devices (RPD); however, we question the utility of a numerical output. In this study, we aimed to examine the relationship between facial features and FF and explore the implications and validity of current fit test standards. A single accredited fit tester provided a test on a relatively large population of ‘real world’ RPD users, using the same...