Kansas Suggested Schools Use Chemical Foggers To Fight COVID. Here's Why They Shouldn't

State officials told Kansas schools they could fill the air with chemical mist to fight COVID-19 in classrooms.

The suggested gadgets coat doorknobs, tables and other surfaces with disinfectant.

But when the Kansas News Service showed the state guidance on electrostatic sprayers and foggers to scientists, one called it “surprising and disappointing.” Another classified it as “a huge error.”

The foggers and sprayers could actually make the air unhealthier, experts warned, without making people safer from COVID-19.

“It’s very unfortunate,” said Jose-Luis Jimenez, an expert in air chemistry and disease transmission at the University of Colorado Boulder.

The state’s recommendation reflects, in part, lingering public confusion over how COVID-19 spreads, and reluctance at the Centers for Disease Control and Prevention to back off of the idea that germs on surfaces fuel the pandemic.

The CDC recently acknowledged that surfaces appear to pose little risk compared to air, catching up to scientists who have argued that for many months.

That undercuts the already questionable case for using electrostatic sprayers and foggers in classrooms.

“The science is clear,” said Joseph Allen, a professor at Harvard University’s School of Public Health.

“The idea that you have to cover every surface in the room with a disinfectant every day doesn’t make sense,” he said.

The Kansas News Service took scientists’ concerns to the state education and health departments, both of which worked on the school guidance. A Kansas Department of Health and Environment spokeswoman said the advice on sprayers and foggers is outdated and not recommended.

An education department spokeswoman said the state commissioner would confirm the matter with health officials. He could then recommend that the State Board of Education make changes to the part of its 1,200-page pandemic guidelines that discusses the disinfectants.

Trying to stay safe

When the pandemic hit last year, panic over germs opened new markets for sellers of foggers, sprayers and (more below) electronic air cleaners.

School leaders bombarded experts like professor Jimenez with emails asking for help making sense of the parade of ads they received.

Manufacturers contacted Jimenez, too, seeking his blessing. He would ask to see details that verified the safety of their products, and especially the chemical side effects.

“Most people don’t write again,” he said. “Some people proceed to insult me.”

Electrostatic foggers and sprayers add a static charge to droplets of disinfectant to help the chemicals stick better to surfaces. The idea is to clean everything from walls and desks to nooks and crannies on a keyboard.

The chemical content varies, but chemistry professor Douglas Collins of Bucknell University wouldn’t want to breathe it. Collins says studies of the content focus on short-term health effects, not long-term toll.

“Even if you’re emitting a small amount,” he said, “the cumulative exposure can be large because … teachers and students are in the building for six hours a day, every day, five days a week.”

Schools could avoid the respiratory risk by using the devices properly, he said, such as spraying overnight and letting hours pass before anyone enters the building again. But he offers two caveats.

First, trained professionals should operate them. Second, schools would do better to spend their time and money on methods that combat COVID’s spread through the air.

Lost opportunity?

Experts agree that schools should stick to their normal cleaning practices, such as wiping tabletops by hand.

They should teach proper hand washing and use of hand sanitizers, too.

That’s enough to curb surface transmission of COVID-19, and helps with other communicable diseases, too.

So how to tackle the bigger risk of catching COVID-19 from particles in the air?

Buy good air filters and bring in more fresh air from outdoors.

Those measures can also help against asthma attacks and chronic conditions, stop other airborne germs, and make people feel better and learn better at school.

Congress sent billions of dollars in stimulus funds to schools during the pandemic, which Allen calls a “once-in-a-generation opportunity” to improve air quality after decades of underinvestment in what schoolkids breathe.

But he and other scientists fear companies selling fancy-sounding but unproven devices will cost communities their chance to make common sense improvements that would help children for decades to come.

“We’re going to end up somehow with … worse air quality,” said building scientist Marwa Zaatari, a board member for the U.S. Green Building Council. “And no one seems to sort of grasp the extent of the problem.”

Schools in Kansas and elsewhere ponied up for electronic air cleaners that claim to defeat the virus with chemistry, but that Zaatari said may do little more than generate ozone, formaldehyde, ultrafine particles or other substances that cause cancer or other conditions.

“I call it the art of selling nothing,” Zaatari said. “They do nothing.”

Electronic air cleaners go by a long list of names, such as bipolar ionizers. Government agencies never recommended the devices, but neither did they stop schools from buying them.

Zaatari and Lawrence-based building scientist Marcel Harmon cowrote an open letter cautioning against the devices. Other prominent researchers signed on.

Zaatari also raised funds to have the Illinois Institute of Technology start testing the devices, which make dramatic and unproven claims about eliminating nearly 100% of COVID-19 virus from the air through chemical reactions with no health risks.

Truly better air

Scientists at Harvard recommend the air in a classroom should change out fully about four to six times every hour.

That means replacing it with outdoor air, properly filtered indoor air, or a combination of the two.

Most schools likely don’t hit that target, or have any clue how close they are. Harvard offers a five-step guide to help them measure ventilation.

Then they can supplement it by installing high-quality filters, such as MERV-13s, in their heating and cooling systems, or placing portable HEPA filter units in classrooms.

Allen calls those the “tried and true” approaches. They’re backed by solid science.

With those, even schools hamstrung by less-than-ideal built-in ventilation systems and windows that don’t open can hit the target of changing their air several times an hour.

“There’s always something you can do,” he said.

Celia Llopis-Jepsen reports on consumer health for the Kansas News Service. You can follow her on Twitter @celia_LJ or email her at celia (at) kcur (dot) org. The Kansas News Service is a collaboration of KCUR, Kansas Public Radio, KMUW and High Plains Public Radio focused on health, the social determinants of health and their connection to public policy. Kansas News Service stories and photos may be republished by news media at no cost with proper attribution and a link to ksnewsservice.org.