Collaborative Proposal: RAPID: Thermal Sterilization of Personal Protective Equipment Contaminated with SARS-CoV-2

Engineering - As the COVID-19 pandemic continues to spread, medical workers in the United States face a dire shortage of personal protective equipment, including masks, face shields, and gowns. As a result, many doctors and nurses are reusing personal protective equipment intended to be discarded after a single use and thereby increasing their risk of contracting the SARS-CoV-2 virus that causes COVID-19. These medical workers, and also the general public, urgently need reliable guidelines for sterilization of personal protective equipment to enable safe reuse. Dry heat sterilization can be performed almost anywhere (including home ovens and rice cookers), and viruses inside of crevices or within fabrics are easily inactivated; this project will provide evidence-based guidelines for the time required to achieve sterilization at a given temperature. The project will also enable prediction of the lifetime of human coronaviruses across various climates, which will be of extreme importance to epidemiologists in predicting the spread of SARS-CoV-2 as well as the severity of a resurgence of the COVID-19 pandemic that may accompany the return of colder weather this upcoming autumn and winter.

This collaborative research project will produce a thermodynamic model that combines a framework built on the Arrhenius equation and the rate law with both existing and forthcoming experimental data to accurately describe the thermal inactivation time of SARS-CoV-2. The proposed thermodynamic model will treat viruses as large molecules that undergo thermal denaturation and will be used to predict inactivation times for viruses, including SARS-CoV-2, by incorporating physical properties of each virus as inputs to determine the dependence of viral inactivation rate on temperature and other environmental conditions. The project will aim to achieve three objectives, namely: (1) to model the inactivation of SARS-CoV-2 due to thermal degradation, including the effects of humidity, pH, surface material, and other conditions in addition to temperature; (2) to experimentally demonstrate sterilization due to thermal inactivation of SARS-CoV-2 on medical personal protective equipment and refine the thermodynamic model by incorporating data from these experimental results; and (3) to characterize thermal degradation of personal protective equipment during repeated thermal sterilization cycles. This work will lead to an unprecedented fundamental understanding of the thermal inactivation of viruses that will help fight the current COVID-19 pandemic and provide the basis for modeling viruses that cause future outbreaks.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.