New Air Filter For Cars Reduces Ultrafine-Particles Exposure By 93%

A new type of high-efficiency cabin air filter (HECA) has been developed that can reduce ultrafine particles (UFPs) exposure by as much as 93%, while also keeping carbon dioxide levels low—a notable development for those that drive a lot, especially in highly polluted regions/cities.

For a bit of background, most modern cars feature cabin air filters, but these typically only block 40-60% of the UFPs in the air when in “outdoor air mode” — something that I’m sure anyone who has driven behind a diesel-exhaust-spewing truck is aware of. A filter capable of blocking up to 93% of UFPs is a substantial improvement over existing technologies.

The ACS press release provides more:

These particles are 100 nanometers or less in diameter; about a thousand of them could fit across the width of a human hair. Studies suggest that UFPs, which are found in automotive exhaust, may be linked with health problems. Switching the venting system into “recirculation mode” reduces UFPs by 90 percent, but because the interior is closed off from the outside, exhaled carbon dioxide can potentially build up to levels that could impair decision-making. To address this challenge, researchers Yifang Zhu and Eon Lee decided to develop a method that would simultaneously reduce UFPs inside cars, while also allowing carbon dioxide to escape.

They developed HECA filters that could reduce UFP levels by an average of 93 percent in 12 commercially available vehicles while driving in outdoor air mode. Compared with the original manufacturer-installed filters, the new one is made of synthetic fibers of much smaller diameters. Carbon dioxide remained at a “reasonable” level, they say.

It’s currently unclear when these new filters will be commercially available.

The new research was just published in the ACS journal Environmental Science & Technology.