Effects of Ultraviolet Germicidal Irradiation

The authors exposed material coupons and straps from four models of N95 filtering facepiece respirators to a range of doses of ultraviolet germicidal irradiation to test particle penetration, flow resistance, bursting strengths of coupon layers, and breaking strength of straps. They found small effects on filtration performance and almost no effect on flow resistance, but a reduction in the strength of respirator materials of more than 90% in some models and a 20-51% reduction in breaking strength of straps. The authors suggest that ultraviolet germicidal irradiation is a possible method to disinfect respirators for reuse, but the respirator model used should first be tested to determine the maximum number of disinfection cycles and the dose required to inactivate the specific pathogen.