The efficiency of Grignard Pure™ to inactivate airborne SARS-CoV-2 surrogate

Grignard Pure™ (GP) is a unique and proprietary blend of Triethylene Glycol (TEG) and inert ingredients designed for continuous antimicrobial treatment of air. GP received approval from the US EPA under its Section 18 Public Health Emergency Exemption program for use in seven states. This study characterizes the efficacy of GP for inactivating MS2 bacteriophage – a non-enveloped virus widely used as a surrogate for SARs-CoV-2. Experiments measured the decrease in the airborne viable MS2 concentration in the presence of different concentrations of GP from 60 to 90 minutes, accounting for both natural die-off and settling of MS2. Experiments were conducted both by introducing GP aerosol into air containing MS2 and by introducing airborne MS2 into air containing GP aerosol. GP is consistently able to rapidly reduce viable MS2 bacteriophage concentration by 2-3 logs at GP concentrations of 0.02 mg/m3 to 0.5 mg/m3 (corresponding to TEG concentrations of 0.012 mg/m3 to 0.287 mg/m3). Related GP efficacy experiments by the US EPA, as well as GP (TEG) safety and toxicology, are also discussed. Synopsis Limited research on the germicidal properties of triethylene glycol against airborne pathogens was conducted during the 1940s and 50s. This paper investigates the inactivation rate of airborne bacteriophage MS2 by Grignard Pure™ product, containing a unique and proprietary blend of Triethylene Glycol (TEG) and inert ingredients. ### Competing Interest Statement Grishma Desai is an employee of Grignard Company LLC, which makes the Grignard Pure product. Etienne Grignard is the Founder and CEO of Grignard Pure LLC which has funded some of the research presented in this paper. The remaining authors have no conflicts of interest to declare.