Impact of test methodology on the efficacy of triethylene glycol (Grignard Pure) against bacteriophage MS2

Abstract

The COVID-19 pandemic has raised interest in using chemical air treatments as part of a strategy to reduce the risk of disease transmission, but more information is needed to characterize their efficacy at scales translatable to applied settings and to develop standardized test methods for characterizing the performance of these products. Grignard Pure, a triethylene glycol (TEG) active ingredient air treatment, was evaluated using two different test protocols in a large bioaerosol test chamber and observed to inactivate bacteriophage MS2 in air (up to 99.9% at 90 min) and on surfaces (up to 99% at 90 min) at a concentration of approximately 1.2 − 1.5 mg/m³. Introducing bioaerosol into a TEG-charged chamber led to overall greater reductions compared to when TEG was introduced into a bioaerosol-charged chamber, although the differences in efficacy against airborne MS2 were only significant in the first 15 min. Time-matched control conditions (no TEG present) and replicate tests for each condition were essential for characterizing treatment efficacy. These findings suggest that chemical air treatments could be effective in reducing the air and surface concentrations of infectious pathogens in occupied spaces, although standard methods are needed for evaluating their efficacy and comparing results across studies. The potential health impacts of chronic exposure to chemicals should also be considered, but those were not evaluated here.

EDITOR:

• Shanna Ratnesar-Shumate

Acknowledgements

The authors gratefully acknowledge members of the EPA Project Team, the members of Jacobs Technology, Inc. (JTI) supporting the EPA Homeland Security and Materials Management Microbiology lab and the JTI Aerosol Science Team, Adam Burdsall and Marc Carpenter for internal technical reviews of this manuscript, and Ramona Sherman and for quality assurance support.

Disclaimer

The EPA, through its Office of Research and Development, directed the research described herein conducted through contract 68HERC20D0018 with Jacobs Technology, Inc. It has been subjected to the Agency’s review and has been approved for publication. Mention of trade names, products or services does not convey official EPA approval, endorsement, or recommendation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are openly available at https://doi.org/10.23719/1528421.