Trump’s CDC boss Dr. Robert Redfield joins Big Ass Fans, which touts unproven COVID-killing tech

Dr. Robert Redfield, who was director of the federal Centers for Disease Control and Prevention under former President Donald Trump, has joined Big Ass Fans, lending his scientific credibility to a company division that says its controversial ion-generating technology kills the coronavirus.

The company charges $9,450 for a fan with technology that academic air quality experts question.

As the company’s new strategic health and safety adviser, Redfield follows Dr. Deborah Birx, Trump’s White House coronavirus response coordinator, into the booming air purifying industry. Birx signed on last month with ActivePure, a company that also is promoting what it describes as virus-destroying technology but markets some devices that run afoul of California indoor-air quality rules, according to a KHN investigation.

The two former Trump administration coronavirus task force members bring name recognition to companies selling products advertised to make it safer for people to gather inside schools, offices, gyms and stores without needing to wear masks. The companies tout 99.9% coronavirus kill rates.

Academic indoor-air quality experts who criticize certain claims about COVID-killing technology say the industry-funded studies often focus on results of tests run in a space ranging in size from a shoebox to a cabinet that don’t reflect conditions in a large room. Studies backed by the industry rarely make clear whether the touted “virus-killing” ions or molecules are doing the work, experts say, and whether any improvements come from a fan or filter on a device.

“There’s no other way to say it — it’s completely unproven whether these devices would work in a real-world setting,” Timothy Bertram, a chemistry professor who studies aerosol particles at the University of Wisconsin-Madison, said of devices that claim to attack molecules in midair.

Redfield, who led the CDC during the Trump administration’s pandemic response, did not respond to requests for comment.

“Proper ventilation has a major role to play in mitigating transmission of COVID-19 and other respiratory pathogens,” Redfield said in a Big Ass Fans news release. “Big Ass Fans is a leader in designing airflow systems and making places where we live, work and play safer.”

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Academic air quality experts, though, say high-profile physician sign-ons amount to celebrity endorsements.

“I’d much rather see good data transparently released than listen to Deborah Birx talk about how good this technology is when I know she isn’t an expert on air disinfection,” said William Bahnfleth, an architectural engineering professor at Penn State who studies indoor air quality and leads the American Society of Heating, Refrigerating and Air-Conditioning Engineers Epidemic Task Force.

Bertram said he studied the performance of ion- and hydroxyl-releasing devices in classrooms and found that some emitted ozone, a gas associated with the onset or worsening of asthma. Others created other new small particles.

When it came to improving ventilation, none performed as well as a HEPA filter, he said, which, together with a MERV-13 filter in a heating system and increased outside ventilation, is the standard recommendation. Bertram did not say which devices he reviewed, saying that will be detailed in a forthcoming study.

University of Wisconsin-Madison

Big Ass Fans is entering the coronavirus air-purifying market with brand recognition based on its uncontroversial air-moving mega-fans. Its Clean Air System fans already are being used in schools and companies including Toyota, Tiffany & Co. and Orangetheory Fitness.

Some Clean Air System fans use UVC light, widely considered an effective air-cleaning technology.

Other fans use bipolar ionization, a technique that the federal Environmental Protection Agency warns is “an emerging technology, and little research is available that evaluates it outside of lab conditions,” adding that evidence of its effectiveness is less documented than the evidence for far more established choices like air filtration.

Big Ass Fans spokesman Alex Risen said in an interview that its technology is just one layer of protection against the coronavirus.

The company, headquartered in Lexington, Kentucky, says its technology “pairs scientifically proven air-purifying technologies with powerful airflow solutions. This results in a system that kills 99.99% of pathogens to keep your people protected and your business booming.”

The company charges about $500 to $1,500 more for fans with Clean Air System technology.

During the pandemic, federal funding to buy such devices for schools has exploded, with roughly $193 billion available so far. And Congressional Democrats are pushing for $100 billion more. With community pressure to reopen classrooms, school officials have begun to invest heavily in air cleaning technology, though some experts worry that possible risks are not being considered.

The EPA has warned about bipolar ionization’s ability to generate ozone and other potentially harmful byproducts indoors. A study by top indoor-air quality experts that was published in the journal Building and Environment found that another company’s bipolar ionization technology created other byproducts, including toluene, which can have developmental effects after long-term inhalation exposure.

Risen said that the Big Ass Fans ionization technology does not emit ozone or other byproducts and is not “putting bad things into your lungs.” He said the products do not emit hydrogen peroxide.

ActivePure, the air-cleaning company Birx has signed on with, makes air cleaners that emit gaseous hydrogen peroxide, which it says can seek out and destroy viruses, mold and bacteria, according to the KHN investigation.

“We know that we’re not producing any negative products,” Risen said. “We know that, at the concentrations that you’re at, you’re not getting negative effects.”

Joe Urso, ActivePure Technologies’ chief executive office,, said the “FDA has cleared a number of devices that emit hydrogen peroxide into the ambient air at a safe level for people to breathe, including our ActivePure Medical Guardian.”

Bahnfleth said Big Ass Fans had made more of a good-faith effort with its studies than others. But he said that, without measuring potential gaseous byproducts, the research was not complete.

Illinois Institute of Technology

“They still do nothing to address potential adverse impacts of chemical byproduct exposure,” said Brent Stephens, an indoor-air quality expert who reviewed Big Ass Fans’ Clean Air System’s reports and leads the civil, architectural and environmental engineering department at the Illinois Institute of Technology.

Stephens said the controlled testing spaces — without people or furniture or other products that would be in a classroom or office — did not reflect real-world circumstances. And he worried about the “really high” ion counts, saying he would not recommend them for occupied spaces.

Echoing those concerns, Bahnfleth pointed to a study that found adverse health effects such as increased oxidative stress levels — which are linked to cancer and other neurological diseases — for those exposed to a high number of negative ions.

Experts said more research is needed because bipolar ionization, such as that used by Big Ass Fans, produces both positive and negative ions.

Risen defended the safety of ions, noting they occur naturally.

It’s hard to tell whether the fan moving the air or the bipolar ionization is having an impact on the virus in the studies provided by Big Ass Fans, said Delphine Farmer, a Colorado State University associate professor who specializes in atmospheric and indoor chemistry. Farmer said that, without real-world testing, it’s unclear what sort of reaction this product could have when exposed to classroom fumes from paint, glue or markers.

“Anything that actually destroys a virus is potentially doing other chemistry as well,” she said.

Another Clean Air System study claimed a 99.999% reduction from the air of COVID-19.

KHN (Kaiser Health News) is a national newsroom producing in-depth journalism on health issues.