Abstract View
Germicidal Ultraviolet Light Does Not Damage or Impede Performance of N95 Masks Upon Multiple Uses
ZHE ZHAO, Zhaobo Zhang, Mariana Lanzarini-Lopes, Shahnawaz Sinha, Hojung Rho, Pierre Herckes, Paul Westerhoff, Arizona State University
Abstract Number: 485
Working Group: Health-Related Aerosols
Abstract
The outbreak of COVID-19 pandemic is causing an increasing need of personal protection equipment (PPE) worldwide, including the demand for facial breathing masks used by healthcare workers. Disinfecting and reusing these masks may offer benefits in the short-term to meet urgent demand for healthcare workers. In this paper, based on previous study that 1J/cm2 UV dose could achieve over 3-log reduction in recoverable virus, we demonstrated germicidal ultraviolet irradiation can be used to disinfect both N95-rated and non-rated surgical masks. Either 265nm LEDs or 254nm low pressure UV lamps at 1J/cm2 and 10J/cm2 had no significant influence on the masks’ ability to remove aerosolized virus-sized particles. Additional testing on physical properties showed no change in polymer structure, surface functional groups, morphology and surface hydrophobicity for multiple layers in the mask before and after UV irradiation, and no change in pressure drop or tensile strength of mask materials. Results were similar when applying 254nm low-pressure UV lamps and 265nm light emitting diodes. Based on the findings and design feasibility considerations, a 254nm UV treatment system and operational manual were prepared to enable treatment and reuse of N95 facial masks. Findings from this study can not only provide short term strategies to reuse of PPE materials but also contribute to the basis of plans for long term practices and help to deal with the shortage of PPE materials during future unanticipated pandemics.