Canadian Researchers Test Indoor Air Decontamination Appliances for Cars

April 7, 2017

Washington, D.C. – April 7, 2017 –The first ever peer-reviewed test of decontamination devices for car interiors has been completed. The quickest device took one and a half hours to remove pathogenic microbes from interior air. The research is published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology

Now that such appliances are being marketed, consumers deserve reliable information on how well they work, said corresponding author Syed A. Sattar, PhD, Professor Emeritus of Microbiology, Faculty of Medicine, University of Ottawa, Canada. 

In the study, the investigators “salvaged parts from a four door sedan and reassembled them in our laboratory to recreate the passenger cabin,” said Sattar, who is also Chief Scientific Officer, CREM Co. Labs, Mississauga, Ontario, Canada. The mock-up was housed within a biosafety level 2 containment facility, to guard against the escape of pathogens used in the testing. 

“The mock-up of the car was modified so that the air inside it could be contaminated with a microbe known to spread by indoor air,” said Sattar. The first step was to determine if that microbe could survive in in-car air as well as it does in other indoor settings. Once this was established, the investigators contaminated the in-car air with Staphylococcus aureus, an oft pathogenic bacterium “well-known for its ability to spread by air indoors,” said Sattar. “The objective was to determine the time necessary for each device to reduce the level of [pathogen in the air] by at least 99.9%,” he said. 

Two of the devices achieved such a reduction within two hours, said Sattar. The third took nearly ten hours to do so. But the average American commute is only 25.4 minutes each way, according to the US Census Bureau. (Canadian commutes take a similar amount of time.) That doesn’t give any of the devices enough time to finish a decontamination during a typical commute. 

“This is the first peer-reviewed study describing a laboratory set-up to assess the fate of harmful airborne microbes inside the family car, and also to test how well commercial air decontamination devices perform under field-relevant conditions,” said Sattar. “The use of this set-up could, indeed, discriminate between promising and poor performers, thus allowing for the development and introduction of better testing standards for more reliable label claims and greater consumer safety.”

Sattar noted that the system could be used for testing decontamination of other types of airborne microbes, and particulates. 


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