Decontamination of E. coli and S. epidermidis on Cloth Masks with Ultraviolet Germicidal Irradiation

Abstract

Spurred by a global pandemic, precautions have been taken by the general public to slow the spread of the respiratory virus called COVID-19. As Cloth Masks have become staples in protection during this time, it is important to understand any limitations that could arise when using a product. Several studies have found that certain methods of decontaminating Cloth Masks, so they may be reused safely, can result in slight degradation. This study analyzes the decontamination method of Ultraviolet Germicidal Irradiation (UVGI) on Cloth Masks that have different ply counts. Using both Escherichia coli and Staphylococcus epidermidis, three different masks were contaminated with bacterial colonies then put through a session of UVGI to sterilize the fabric. Once the session was over, masks were collected and analyzed for effectiveness of decontamination and changes in fabric pore size. It was found that when decontaminating the Cloth Masks, regardless of the bacteria they have been contaminated with, there was a positive correlation between the number of plies a mask had to the amount of bacteria able to be decontaminated. Additionally, there was a negative relationship between the number of plies a mask had and the degradation of the material over time. UVGI provides an effective method of decontamination for Cloth Masks now that its benefits and limitations have been understood.