Airborne Virus Concerns

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By Gediminas “Gedi” Mainelis, Ph.D.; Emanuel Goldman, Ph.D.; Antony Galione, MA Ph.D.; Don Schaffner, Ph.D. & contributing authors | October 31, 2022 << Back to Articles Airborne Virus Concerns

The Problem: Transmission of SARS-CoV-2 is predominantly through inhalation

A recently published research paper from the Department of Environmental Health Sciences of University of Michigan School of Public Health examined the potential infection risks of people exposed to SARS-CoV-2 virus in publicly accessible non-healthcare environments, concluding that inhalation is the predominant route of exposure compared to surface contact.

These authors also estimated the risk of airborne transmission to be 20,000 times higher than from contact with contaminated surfaces. This further underscores the U.S. Centers for Disease Control and Prevention’s (CDC) statement that the principal mode by which people are infected with SARS-CoV-2 is through exposure to respiratory droplets carrying the infectious virus.

This article is the first in a series from Grignard. Access part two here and read part three here.

The Solution: Reduce the immediate level of inhaled viral load

 On January 15, 2021, the U.S. Environmental Protection Agency (EPA)  issued a Section 18 Emergency Exemption for the use of Grignard Pure® as the first-of-its-kind airborne antiviral effective at killing more than 98.5% of the SARS-CoV-2 virus in the air. Grignard Pure is a proprietary mixture containing the active ingredient triethylene glycol (TEG). It is aerosolized and dispersed into the air via a handheld or portable device. The EPA issued a one-year renewal of the Emergency Exemption on January 15, 2022.

In a recent study, currently under peer review, researchers, including independent members of Grignard Pure LLC’s science advisory team, reported on the effectiveness of Grignard Pure to inactivate the bacteriophage MS2 (the virus—a non-enveloped viral microbe used widely as a SARS-CoV-2 surrogate). The authors reviewed the results of extensive efficacy testing undertaken by two accredited third-party labs, which the company had submitted to the EPA.

The objective of the efficacy testing was to measure the reduction in airborne concentrations of viable virus in the presence of differing Grignard Pure aerosol concentrations ranging from 0.02 mg/m3 to 0.5 mg/m3. Measurements were taken at 30 seconds and 15, 60, and 90 minutes. To account for natural die-off and settling of the virus over time, these measurements were compared with measurements at the same time points of the levels of the virus in the air without any Grignard Pure.

Two protocols were employed:

  • Episodic treatment: Introducing aerosolized Grignard Pure into the air containing the virus, using a single shot, 4-second spray (using a vaporizer or nebulizer)—to simulate “episodic” treatment of indoor spaces such as hotel rooms, break rooms, classrooms, movie theatre auditoriums, or rental cars.
  • Continuous treatment: Introducing virus into air containing Grignard Pure, in a controlled time release where Grignard Pure was dispersed to maintain a consistent concentration, to simulate “intermittent” treatment of indoor spaces, where a device could be placed to provide “continuous” dispersion (delivered intermittently to maintain the proper level of concentration in the air).


The tests clearly demonstrated the efficacy of Grignard Pure at aerosol concentrations between 0.02 mg/m3 and 0.5 mg/m3 (corresponding to TEG aerosol concentrations of 0.01 mg/m3 to 0.29 mg/m3) to significantly reduce virus concentrations (i.e., airborne viruses). EPA’s approval allows Grignard Pure (GP) to be used in occupied indoor spaces to provide an added layer of protection by reducing the levels of airborne virus.

The tables below show the percentage reduction of the virus in the air at three-time intervals (0.5 min, 15 min, 60 min) from experiments done in two different laboratories.

Looking ahead

Grignard Pure is currently working to secure permanent approvals from the EPA for use against multiple airborne pathogens and mold spores in both unoccupied and occupied indoor spaces.

You can read the complete science paper here.

Links to independent health and safety assessments:

About the Author.

Gediminas “Gedi” Mainelis, Ph.D. 
Gediminas “Gedi” Mainelis, Ph.D., is a professor at the Department of Environmental Sciences, Rutgers University. He has a Ph.D. in Environmental Health from the University of Cincinnati, Ohio. Dr. Mainelis’ research has focused on various aspects of health-related aerosols, including development of novel bioaerosol collectors; analysis of factors affecting bioaerosol sampling, analysis, and control; and integration of bioaerosol sampling with modern microbiological analysis techniques.

In the past few years, Dr. Mainelis has expanded his research into nanoparticle exposure assessment, airborne delivery of anti-cancer drugs, indoor air quality in green buildings, and use of robotic surrogates for exposure assessment. Dr. Mainelis is a recipient of the CDC/NIOSH Career Award, Twinning Fellowship from the National Academy of Sciences, and Research Excellence Award from the School of Environmental and Biological Sciences of Rutgers University. He is currently serving as chair of the health-related Aerosols Working Group of the American Association for Aerosol Research. 

Emanuel Goldman, Ph.D. 
Emanuel Goldman graduated with honors from the Bronx High School of Science in 1962,  received a B.A. cum laude from Brandeis University in 1966, where he was a chemistry major, and he completed his Ph.D. in Biochemistry at M.I.T. in 1972. He did postdoctoral  research at Harvard Medical School and the University of California, Irvine, before  joining the faculty of New Jersey Medical School in 1979, where he rose through the ranks  to professor in 1993. Among his awards and honors, he was a Damon Runyon Fellow, A Lievre  Senior Fellow of the California Division-American Cancer Society, and a recipient of a  Research Career Development Award from the National Cancer Institute.

Among his service activities, he was an officer and organizer of the NY-NJ Molecular Biology Club, served as a full member of an American Cancer Society Study Section, and continues to serve on the editorial boards of the Protein Expression and Purification and Applied and Environmental Microbiology journals. He was also twice elected by his colleagues to serve as president of the university chapter of American Association of University Professors, and he was elected to serve as vice president and subsequently president of the Faculty Organization of NJMS.

Antony Galione, MA Ph.D. FRS FMedSci 
Dr. Galione was educated at Trinity College, Cambridge, and received a B.A. in Natural Sciences (pharmacology part 2) in 1985 and his Ph.D. (zoology) in 1989, having worked on the role of calcium oscillations in cell activation in Sir Michael Berridge's laboratory. After a short spell at UCL working on mammalian fertilization with Michael Whitaker, he went to Johns Hopkins University as a Harkness Fellow studying the role of calcium signals in early development. Returning to the UK in 1991, he joined the Department of Pharmacology. He has been successively a Beit Memorial Fellow, Wellcome Trust Career Development Fellow, and Wellcome Trust Senior Fellow in basic biomedical research. 

He was elected to a Tutorial Fellowship at New College in 1998 in conjunction with a proleptic University appointment, appointed to a titular Professor of Pharmacology in 2002, and elected to the Professorship of Pharmacology and a Professorial Fellowship at LMH in 2006. He was head of the Department of Pharmacology from 2006-2015. 

Dr. Galione received the 2001 Novartis Prize of the British Pharmacological Society for scientific contributions to pharmacology. He became a Fellow of the Academy of Medical Sciences in 2010 for his contributions to the advancement of medical science, and in 2016 he was elected a Fellow of The Royal Society for his work on calcium signaling. 

Don Schaffner, Ph.D. 
Dr. Donald W. Schaffner is Extension Specialist in Food Science and Distinguished Professor at Rutgers University. His research interests include quantitative microbial risk assessment, predictive food microbiology, handwashing, and cross-contamination. He has authored more than 200 peer-reviewed publications, as well as numerous book chapters and abstracts.

Dr. Schaffner has served on a variety of expert committees, including service to U.S. National Academy of Sciences, the World Health Organization, Food and Agriculture Organization of the United Nations, the Institute of Food Technologists (IFT), and U.S. National Advisory Committee on Microbial Criteria for Foods. Dr. Schaffner is active in various groups, including the International Association for Food Protection (IAFP), IFT, the Society for Risk Analysis, the American Society for Microbiology, and the Conference for Food Protection.

Dr. Schaffner was elected a Fellow of IFT in 2010, the American Academy for Microbiology (ASM) in 2014, and IAFP in 2017. He was elected the secretary of the IAFP in 2010, a five-year commitment, including service as president of the organization from 2013-2014. He is the co-host of two podcasts on food and risk: Food Safety Talk and Risky or Not. Since the start of the pandemic, he has been interviewed for both TV and print media (including New York Times, Washington Post, and Wall Street Journal) on SARS-CoV-2 and COVID-19 and the food supply. 

Other notable authors:

  • Dr. Gurumurthy Ramachandran, Department of Environmental Health and Engineering, Johns Hopkins Education and Research Center for Occupational Safety and Health, Bloomberg School of Public Health, Whiting School of Engineering, The Johns Hopkins University.
  • Dr. Altaf Lal, Former Chief of Molecular Vaccine Section, CDC.
  • Dr. Jack Caravanos, Clinical Professor of Environmental Public Health Services, New York University. [email protected].
  • Dr. Toni K. Choueiri, Dana-Farber Cancer Institute, Harvard Medical School.
  • Dr. Andre Fay, Pontifícia Universidade Católica do Rio Grande do Sul, School of Medicine.