Effects of ultraviolet germicidal irradiation (UVGI) on N95 respirator filtration performance and structural integrity.
Lindsley WG; Martin SB Jr.; Thewlis RE; Sarkisian K; Nwoko JO; Mead KR; Noti JD
J Occup Environ Hyg 2015 Aug; 12(8):509-517
The ability to disinfect and reuse disposable N95 filtering facepiece respirators (FFRs) may be needed during a pandemic of an infectious respiratory disease such as influenza. Ultraviolet germicidal irradiation (UVGI) is one possible method for respirator disinfection. However, UV radiation degrades polymers, which presents the possibility that UVGI exposure could degrade the ability of a disposable respirator to protect the worker. To study this, we exposed both sides of material coupons and respirator straps from four models of N95 FFRs to UVGI doses from 120 to 950 J/cm2. We then tested the particle penetration, flow resistance and the bursting strengths of the individual respirator coupon layers, and the breaking strength of the respirator straps. We found that UVGI exposure led to a small increase in particle penetration (up to 1.25%) and had little effect on the flow resistance. UVGI exposure had a more pronounced effect on the strengths of the respirator materials. At the higher UVGI doses, the strength of the layers of respirator material was substantially reduced (in some cases, by >90%). The changes in the strengths of the respirator materials varied considerably among the different models of respirators. UVGI had less of an effect on the respirator straps; a dose of 2360 J/cm2 reduced the breaking strength of the straps by 20% to 51%. Our results suggest that UVGI could be used to effectively disinfect disposable respirators for reuse, but the maximum number of disinfection cycles will be limited by the respirator model and the UVGI dose required to inactivate the pathogen.
Respirators; Respiratory-equipment; Respiratory-protection; Respiratory-protective-equipment; Ultraviolet-radiation; Polymers; Exposure-levels; Risk-factors; Statistical-analysis; Disinfectants; Pathogens; Respiratory-system-disorders; Diseases; Pulmonary-function; Pulmonary-system; Pulmonary-system-disorders;
Author Keywords: Respiratory protective devices; Respiratory infections/prevention; Healthcare workers; Airborne transmission; Ultraviolet light; Disinfection
William G. Lindsley, Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505-2845
HELD; DRDS; NPPTL; DART
Healthcare and Social Assistance; Transportation, Warehousing and Utilities
Journal of Occupational and Environmental Hygiene