Skip to Content
Southwest Center for Occupational and Environmental Health

Inside the Hepa Filter Research of a NIOSH Pilot Project Awardee

Toluwanimi M. Oni, MPH, is a PhD candidate and Hudson Fellow in the Department of Occupational and Environmental Health at the University of Oklahoma Health Sciences Center. He was awarded funding by the Southwest Center for Occupational and Environmental Health (SWCOEH) as part of the NIOSH Pilot Project Research Training Program for his Pilot Project “Efficacy Testing of Acid-treated HEPA Filters for Reduction of Nicotine and Particulate Matter Concentrations in a Controlled Setting”.

“Mr. Oni's dedication throughout his pilot project funded by SWCOEH ERC exemplify the qualities we value in our program participants,” said Jenil Patel, PhD, director of the Pilot Projects Research Training Program at Southwest Center for Occupational and Environmental Health. “His innovative approach to improving HEPA filters demonstrates both his expertise in occupational health and his commitment to addressing pressing public health concerns. Projects like this not only contribute to the career development of occupational epidemiology trainees but also drive forward the progress of science in the field of occupational health. We are proud to support Mr. Oni and look forward to seeing the impact of his research on human health and safety."

To learn more about the study, SWCOEH.org asked Mr. Oni about his research.

SWCOEH.org: What was the objective of you Pilot Project?

Mr. Oni: “Particles and nicotine vapor are often produced when electronic cigarettes are used. These particles and nicotine vapor may be harmful to human health when exhaled in considerable amounts, particularly among vulnerable populations like pregnant women, children, and persons with existing health challenges like asthma patients. Indoor environments with frequent electronic cigarette use may contain substantial amounts of particles and nicotine vapor.

To improve air quality in indoor settings, air purifiers are commonly used. Air purifiers are devices that suck air through High-Efficiency Particle Air (HEPA) filters where particles are trapped, and only clean air is released back into the environment. These HEPA filters are designed to remove at least 99.97% of particles in the air that pass through them. However, HEPA filters could be more effective in removing vapors or gases from the air that passes through them.

This project aimed to improve HEPA filters so they can effectively remove particles and vapors from electronic cigarette use from indoor air. To improve the HEPA filters, a chemical known to trap nicotine was applied to some HEPA filters, and then air containing nicotine from electronic cigarettes was drawn through the HEPA filters.”

SWCOEH.org: What were the main findings of this research?

Mr. Oni: I discovered that the modified and unmodified HEPA filters could not remove up to 99.97% of particles from electronic cigarette use. However, the modified HEPA filters removed more than 99% of the nicotine vapor present in the air from electronic cigarettes. Still, the unmodified HEPA filters could only remove about 50% of the nicotine vapor.

SWCOEH.org: What did you find interesting during your research, and what did you find interesting about the results?

Mr. Oni: Even though some of the filters purchased for the project claimed to be able to remove 99.97% of particles in the air, I discovered that many could not, and I had to adapt my data analyses. Nevertheless, both the inferior and genuine HEPA filters could not remove up to 99.97% of particles from electronic cigarette use present in the air. All the filters did not behave like genuine “HEPA filters” when filtering out particles from electronic cigarettes.

SWCOEH.org: If you had additional funding and time, what would you next like to research on this topic?

Mr. Oni: I would like to extend this study to evaluate how much tobacco smoke particles and vapors present in the air can be removed by modified HEPA filters. I also look forward to deploying these modified HEPA filters in real-world indoor settings where there is a lot of tobacco use or electronic cigarette use, such as smoking in restaurants, bars, casinos, etc., and assessing their ability to reduce particles and harmful vapors.

SWCOEH.org: Is there anything else you’d like to add?

Mr. Oni: I had to adapt and be creative when initial experiments didn’t go as planned. However, the results of this project will be an essential intervention for public health research focused on reducing human exposure to tobacco and electronic cigarette products.


The SWCOEH provides graduate-level training opportunities for occupational and environmental health professionals through our industrial hygiene, occupational and environmental medicine, occupational epidemiology, and Total Worker Health® programs.