“Your typical HEPA filter is not going to be able to remove coronavirus from the air,” said Dr. Erin Sorrell, an assistant professor of microbiology and a member of Georgetown’s Center for Global Health Science and Security. “The filter itself is .3 microns and the virus itself is roughly .1 microns.”

The issue, according to experts, are the air filters themselves. Most commercially available air purifiers are high-efficiency particulate air (HEPA) filters. They can remove many particles from the air, but coronavirus is too small to be affected.

One IndieGoGo air purifier campaign sent out an email titled “Fight Coronavirus with cutting edge tech,” saying that “This tech is being installed in hospitals in Wuhan.” It claims that the air purifier can “eradicate virus on a single air pass” in a fundraising video set to upbeat music. The company has raised nearly $7,000 via the campaign, and said it will ship the devices in April.

As ever more coronavirus infections in the US are diagnosed, some companies have begun promoting air purifiers as an effective protection against the virus. However, scientists told BuzzFeed News that air purifiers are not the best preventive measure against the coronavirus.

The purifier on IndieGoGo, called Hextio, also advertises a UVC filter. Dr. Sorrell said a UV filter does kill some viruses, but won’t affect coronavirus as the HEPA filter is not fine enough to suck it up from the air. Even if it could, the process “typically takes about 15 minutes but it varies across viruses.” It’s not clear how long coronavirus would take to kill using UV, Dr. Sorrell clarified. Dr. Aaron Glatt, an IDSA spokesperson agreed, saying the exposure of the virus to UV light “would have to be significant, it could not just be for a second.”

"Indiegogo takes the COVID-19 situation very seriously and, while we are an open platform, have put strict guidelines around virus-related campaigns during this time to ensure the protection and safety of our community," a spokesperson from IndieGoGo told BuzzFeed News. "We do not condone claims about the effectiveness of virus-killing or related products without medical proof and are actively reaching out to campaign owners, including the owners of the Hextio purifier, to ensure all statements related to viruses of any kind are true in nature."

Another air purifier, Molekule, which doesn’t use HEPA filters, is being tested for its ability to kill coronavirus, Bloomberg reports. Yet it is worth noting the company’s previous claims about the effectiveness of its $799 air purifier have been challenged, and it subsequently agreed to withdraw many of them, according to a Wirecutter report. (Molekule spokesperson Kayla Wilkinson told BuzzFeed News the withdrawal is an ongoing legal matter.)

“The best thing to do is to stay in a room alone if you’re sick,” said Dr. Glatt. “And an open window will probably clear out the room better than your typical air purifier.”



The best way to protect yourself from the virus is to thoroughly wash your hands and to use hand sanitizer that’s above 60% alcohol content, ensuring you cover your entire hands and allowing the sanitizer to dry. It’s also key to physically distance yourself from anyone who appears to be sick in public and cover your mouth and nose if you yourself are sick.

“Portable filters are not going to be helpful in capturing coronavirus and could give someone a false sense of security,” Dr. Sorrell said.