What are the Denver Broncos being sprayed with, and does it kill coronavirus?

In a video shared Monday on Twitter, the Denver Broncos can be seen walking through what looks like a metal detector spraying mist over the players before they start the day’s practice session.

The method has been touted as one of the team’s ways of disinfecting players to prevent spread of the coronavirus, but experts aren’t convinced it really works.

The Centers for Disease Control and Prevention says the “primary and most important mode of transmission” for COVID-19 is through close contact with others; coughing, sneezing and even talking and breathing can spread respiratory droplets containing the virus to others.

More recently, experts have recognized the potential for airborne spread of the coronavirus. But touching surfaces, such as a teammate’s jersey or helmet, that has the virus on it is not thought to be of major concern, experts say.

Asymptomatic or not, people carry the virus inside of them, not on the outside. This means that players, if infected, could still have an endless supply of virus to expel after passing through a misting booth designed to prevent just that.

And spraying disinfectant on skin can be dangerous, the World Health Organization said in a May news conference, CNN reported, especially if it has not been evaluated for safety by the Environmental Protection Agency. It can cause respiratory, skin and eye irritation.

“While walk-through sanitizing booths may give players some peace of mind, the effectiveness of this and other mass disinfection methods against the COVID-19 virus is not yet supported by scientific data,” Dr. Choukri Ben Mamoun, professor of medicine and microbial pathogenesis at Yale School of Medicine, told USA TODAY Sports. “It is clear that if a player is infectious while entering the booth, there is a very good chance that he will still be infectious coming out of the booth and will transmit the virus to other players.”

A Broncos’ spokesperson confirmed with multiple media outlets that the disinfectant misted over players is called microSURE, a “non-toxic spray” that “helps protect the players from COVID-19 by killing microbes and pathogens instantly by forming millions of nano-crystalline structures,” Aric DiLalla, the team’s lead writer and senior coordinator of digital content, said on Twitter.

Two of the Broncos have opted out of the 2020 NFL season due to concerns about the coronavirus, according to USA TODAY.

And star pass-rusher Von Miller, who contracted the disease in April but has since recovered, said he considered opting out but decided to play because of the Broncos’ safety protocols, the Denver Post reported.

Company defends product

The Chicago-based company, which has five followers on Twitter, took to social media to address “inaccurate descriptions” of its product as well as “a number of knowledgeable individuals concerned about player safety and liability issues.”

“Although our company does not own the actual misting booths, it has come to our attention that certain media outlets have released stories with inaccurate descriptions of the particular solution…,” microSURE wrote. “While our technology underwent vigorous testing at the University of Liverpool, researchers described the microSURE technology as ‘chemically inert and harmless to humans.’”

“We appreciate your concerns and want to assure you that our intentions are to make the world a safer place and to help save lives immediately,” the company said.

The technology for the spray was developed about 15 years ago, according to microSURE; the company says the disinfectant can stick to surfaces for much longer than “your typical chemical agent,” and it does so by the “physical creation of a mechanical barrier that protects against harmful pathogens,” including SARS-CoV-2, their tweets read.

“It’s the drying process that occurs within minutes that sets up this long-lasting, in some cases, permanent barrier,” Dr. Erwin Lo, neurosurgeon and co-founder of microSURE told USA TODAY Sports. It creates “these tiny spikes to basically puncture the wall of the membranes” of viruses.

Although Lo did not share what the spray is made of with the outlet, he did say it can survive multiple loads of laundry and has been “applied” to FDA and EPA products.

The Broncos open their season on Sept. 14, at home against the Tennessee Titans.