Ultraviolet C light ideal for optimal decontamination of individual N95 respirators

The results showed that -

a. All three decontamination processes reduced bacteria counts similarly.

b. On multivariate mixed model analysis, there were an additional 8.1 colonies of bacteria (95% CI 5.7 to 10.5; p < 0.01) on the inside compared to the outside surface of the respirators.

c. Treatment resulted in a decrease of bacterial load by 8.6 colonies (95% CI -11.6 to −5.5; p < 0.01).

d. Although no decontamination treatment affected the respirator filtration efficiency, heat treatments were associated with the breakdown of thermoplastic elastomer straps.

e. Contamination with fungal and SARS-CoV-2 viral particles were minimal to non-existent.

Therefore, it was concluded that "Time, heat and UVC all reduced bacterial load on reused N95 respirators. Fungal contamination was minimal. Heat could permanently damage some elastic straps making the respirators nonfunctional. Given its effectiveness against microbes, lack of damage to re-treated respirators and logistical ease, UVC represents an optimal decontamination method for individual N95 respirators when reuse is necessary."