Method for Quantifying Fitted Filtration Efficiency of Face Mask and Respirator Products

Face masks and respirators are frequently deployed in critical protective applications (such as medical and construction environments) where fit testing is not routinely performed before each shift. N95 and related testing protocols effectively assess filtration efficiency for respirators that remain tightly fitted throughout activity, but since these protocols prescribe sealing the tested product to the apparatus, they ignore issues of leakage and poor fit that occur in commonplace face mask products. It is therefore vital that new test methods and protocols be developed to better assess the particulate filtration efficiency that is true to the exposure of the wearer when fit and breathability are considered. ITA proposes a novel Fitted Filtration Efficiency (FFE) protocol to assess mask/respirator efficacy on a true exposure basis. Headforms exhibiting a range of facial dimensions representative of published population data will be developed and connected to particle counting equipment to measure the as-worn filtration efficiency of face mask/respirator products against standard challenge aerosols. Acquired data will enable consumers and manufacturers to understand the expected fit and filtration efficiency for products in accordance with face size and shape while also providing an assessment of expected protection factor where quantitative fit testing is not routinely available.