Anti-Fog Solution for Air-Purifying Respirator Lenses

: The anti-fog efficacy of a topical surfactant solution was assessed. Each of three respirators was tested three times with treated and untreated lenses. Each mask was placed on a heated, wetted headform in an environmentally controlled room for 10 min. Miniature cameras mounted in the headform captured images through the respirator lenses. These images were then processed using a custom software program that specified the Snellen visual acuity based on the amount of lens fogging. Average Snellen visual acuities for the untreated left and right lenses were 20/254 and 20/261, respectively. For the treated lenses, average acuities were 20/6 and 20/5 for the left and right lens, respectively. Thus, the tested surfactant solution decreased lens fogging of an air-purifying respirator.