Determination of critical anthropometric parameters for design of respirators

The objectives of this study were 1) to collect useful anthropometric data from 243 workers fit-tested in a continuing respirator fit-test program; and 2) to determine correlation between anthropometric data and Protection Factor obtained from quantitative fit-testing for half-mask respirators. Anthropometric data were collected from two direct facial measurements [nasal root breadth (NRB), and face-length (FL)] and five indirect facial measurements [nose length, nose protrusion, chin length, mouth width (MW), and face width (FW)] from front- and side-view slides of test subjects. For quantitative analysis, the anthropometric data collected in this study were normalized with relevant respirator dimensions (for four different brands and ten sizes). Results of linear regression analysis indicated that correlation coefficients between Protection Factor and anthropometric data (FL, MW, FW and NRB) were respectively - 0.04, 0.22, 0.30 and 0.04. These correlation coefficients are for white males without facial hair. The "critical" anthropometric parameters as apparent from the analysis were MW and FW. However, a person with certain combination(s) of multiple anthropometric parameters may provide a better correlation with Protection Factor.