Editor’s Note: Correction: This article has been revised to reflect that an Odorox distributor, not Pyure, commissioned the ozone test on a Boss XL3. And the article was revised to reflect that Pyure CEO Jean-Francois “JF” Huc said his company provides stringent operating guidelines for use of the company’s air purifiers but did not acknowledge that school staffers are often not warned about the problems they could face if a too-powerful device is used in a too-small room

KHN  — 

Last summer, Global Plasma Solutions wanted to test whether the company’s air-purifying devices could kill Covid-19 virus particles, but could find only a lab using a chamber the size of a shoebox for its trials. In the company-funded study, the virus was blasted with 27,000 ions per cubic centimeter. The company said it found a 99% reduction of virus.

The report doesn’t say how this reduction was measured, and in September, the company’s founder incidentally mentioned that the devices being offered for sale would actually deliver a lot less ion power – 13 times less – into a full-sized room.

The company nonetheless used the shoebox results in marketing its device heavily to schools as something that could combat Covid in classrooms far, far larger than a shoebox.

School officials desperate to calm worried parents bought these devices and others with a flood of federal funds, installing them in more than 2,000 schools across 44 states, a KHN investigation found. They use the same technology — ionization, plasma and dry hydrogen peroxide — that the Lancet COVID-19 Commission recently deemed “often unproven” and potential sources of pollution themselves.