Misting the White House between administrations won’t kill Covid-19 — and it could be harmful, experts say

The federal government is putting $29,000 in taxpayer funds toward a type of cleaning that many experts advise against: misting a disinfectant all over the White House.

A Virginia-based contractor will spray a disinfectant mist throughout the East and West Wings before President-elect Biden moves in, according to a federal contract first reported by TMZ and Politico. The same contractor has done the same procedure for the Navy, including at a weapons station in Virginia.

But prominent expert organizations are clear: misting or fogging disinfectants is not a good way to fight Covid-19.

The World Health Organization specifically recommends against misting as a way to combat Covid-19 in both health care or non-health care settings, saying it is not only unhelpful, but can harm people in the space. So does the American Industrial Hygiene Association, which represents workplace safety and cleanliness experts. And according to the EPA, just three disinfectants — all based on hydrogen peroxide — are even effective against SARS-CoV-2 when used as a mist.

The technique is markedly ineffective unless surfaces are also thoroughly cleaned beforehand, industrial hygienists say. And spraying disinfectant into an office’s air can be a health risk both to the employees who normally work there and to the people tasked with operating the machinery.

“It’s a huge waste of time and effort. It probably isn’t as effective as people say it is. And it runs the risk of somebody actually breathing this stuff in where it may be extremely hazardous,” said J. David Krause, an environmental and occupational health consultant and the past chair of the AIHA’s indoor environmental quality committee. “You really only need to be treating the surfaces that people have been exposed to or can be exposed to,” he added.

Compounding the wasted effort, Krause said, is that in the White House, misting without proper preparation could put priceless works of art at risk. “The conservators at the National Archives are probably freaking out,” he said.

The General Services Administration and the Biden transition team did not respond to STAT’s request for comment about exactly who had authorized the misting contract, what kinds of chemicals would be used, or whether it would pay for more than one misting. The contractor it hired, Didlake, declined to comment.

Misting, fogging, and fumigation are all terms that refer to essentially the same technique: Using machines that can look like an overhyped Nerf gun or a leaf blower, chemicals are sprayed into the air where they will linger and eventually fall.

Each word refers to something slightly different; fumigating for household pests, for example, uses completely different chemicals than fogging a space after a Covid-19 outbreak. Misting and fogging refer to spraying disinfectants and are more similar, but the particles produced during misting are generally larger and fall faster than those produced during fogging.

Before the coronavirus, fogging and misting disinfectants wasn’t popular in health care settings — and the Centers for Disease Control and Prevention largely recommended against doing either in most hospital spaces.

But when the pandemic hit, companies started offering anti-coronavirus misting and fogging services to a variety of businesses hoping to obliterate the virus that causes Covid-19 — and airlines, football stadiums, hotels, country clubs and restaurants all took them up on it.

The problem? Misting and fogging really aren’t effective ways to combat the coronavirus. Chemical disinfectants must have contact with a virus or bacteria in order to kill it — and it’s unlikely that particles of any size would be able to maintain contact with virus particles in the air. Particles in the air move about in small, random ways — so even if a molecule of disinfectant did manage to find a virus, the two probably wouldn’t hang out together long enough for the virus or bacteria to die.

And if what you really want to do is kill any coronavirus particles that have fallen onto surfaces, fogging and misting still can’t replace surface cleaning. If there’s any other dirt or grime on a surface when a misted particle falls onto it, it could block the misted chemical from contacting the virus. (The General Services Administration plans to disinfect surfaces in the traditional way, in addition to the misting, according to Politico.)

On top of all that? We understand now that the coronavirus only lingers on surfaces for a few days, maybe a week. So vacating the White House for a week might actually be more effective than any misting or fogging could ever be, experts said.

“People are spending millions of dollars going around trying to disinfect surfaces,” Krause said. “I think we’re going to look back on this and think, well, what the heck were we doing?” 

Vaporizing chemicals can also be dangerous. In New Jersey, according to a health alert issued by the state government, four EMTs were diagnosed with work-related asthma in 2008 after their ambulances were fogged with disinfectants. (Those disinfectants belong to a different class of chemicals than hydrogen peroxide, which is used in the three products that are approved for fogging against Covid-19.)

The risk isn’t limited to people, either. “A certain category of virucides are corrosive,” said Krause.

During the recent Ebola outbreak, he said, he and other industrial hygienists suggested airlines stop fogging aircraft with hydrogen peroxide-based chemicals because of the risk of corrosion in unseen critical electrical systems. The same corrosion spurred Krause’s worries about the art in the White House.

Jason Marshall, the laboratory director of the Toxics Use Reduction Institute at the University of Massachusetts, Lowell, said he generally agreed with the AIHA guidelines — for most places, misting would be overkill.

A deep clean, followed by another cleaning of any areas that people touch a lot — think elevator buttons or light switches — should be more than enough to prevent transmission after an outbreak, he said, though he acknowledged the White House was certainly entitled to taking a “blanket, do-everything-under-the-sun approach.”

But spraying every SARS-CoV-2-killing disinfectant known to humankind in an office can’t replace a broader set of workplace safety precautions that control the risk of exposure in the first place, Marshall warned.

“If you’re at that point where you think you have to do everything, you’ve done something wrong upstream. You have to reassess the whole process,” he added.

Rather than spraying chemicals into the air, both Marshall and Krause suggested the White House staff take a good, hard look at the ventilation systems.

“When you have an outbreak, it’s going to be in the air, it’s going to be floating around,” Marshall said. Revamping the way outside air is brought into and throughout the offices — and maybe adding a UV light into the HVAC system — might be something worth considering.

Or, again, both Marshall and Krause suggested simply vacating the offices for a week between administrations.

“Nuking the place with chemicals is not needed,” Krause said.