Can UV Light Help Us Reuse Masks
Stephanie Tamkee
David Thompson Secondary
Floor Location : M 099 N

The purpose of this lab is to design a portable disinfecting device that uses UV-C light to decontaminate single disposable masks and determine after how much time and at what distance between the mask and UV light there is no bacterial presence. If successful, the disinfecting device can be used in homes as an alternative to other expensive disinfecting methods and lower the burden on critical environments, like hospitals, to provide a mask disinfection system during mask shortages for large numbers of users. Two distances between the mask sample and the UV light of 3 inches and 6 inches were tested for each of seven chosen time intervals between 30 seconds and 15 minutes. The experiment was executed by applying bacteria collected by cough samples in a petri dish to surgical mask samples which were then placed into the disinfecting device constructed at the predetermined time and distance. Once the process was completed, the mask sample was removed, and another petri dish was used to culture the remaining bacteria which were counted later and analyzed as data.
In the first part of the experiment, the disinfecting device was constructed successfully as designed. During the testing stages of the experiment, the device continued to operate as designed, and results demonstrated a downward trend in bacterial presence on the mask samples as the time of exposure to the UV light inside the device increased. The device performed its best at a 6-inch distance after 15 minutes of exposure, however, according to the slope of the decreasing bacterial presence, it is believed that after an exposure of 16-17 minutes, no bacterial growth would be seen when cultured in agar plates as done in this experiment. The hypothesis predicting that if the device operated as designed, after 10 minutes at a 3-inch distance, the disinfecting device created would successfully decontaminate a single surgical mask of bacteria without visual damage to the mask was not accepted. Although the device worked as desired, according to collected data, the device performed its best with a 6-inch distance between the mask and the UV light after a 15-minute exposure with no visual damage to the mask sample. This prototype, designed for single disposable masks, can have many benefits for common households compared to the current technology on the market, and it is hoped that this innovation can provide assistance to many struggling sectors and the efforts to halt the increase of pollution in the environment during the difficult time of the COVID-19 pandemic and in any future mask shortages.