When the coronavirus spread in the United States last spring, many experts warned of the danger posed by surfaces. The researchers reported that the virus could survive on plastic or stainless steel for days, and the Centers for Disease Control and Prevention advised that someone could become infected if they touch one of those contaminated surfaces and then touch their eyes, nose, or mouth.

The Americans responded with benefits in kind, wiping groceries, quarantining mail, and clearing Clorox wipes on drug store shelves. Facebook closed two of its offices for a “deep clean”. The New York Metropolitan Transportation Authority started disinfecting subway cars every night.

But the “hygiene theater” era may have unofficially ended this week when the CDC updated its surface cleaning guidelines to find that the risk of the virus contracting a contaminated surface was less than 1 in 10,000.

“People can be affected by the virus that causes Covid-19 through contact with contaminated surfaces and objects,” said Dr. Rochelle Walensky, director of the CDC, at a briefing at the White House on Monday. “However, there is evidence that the risk of infection transmission via this route of transmission is actually low.”

The approval is long overdue, say scientists.

“Finally,” said Linsey Marr, an airborne virus expert at Virginia Tech. “We’ve known this for a long time, and yet people are still so focused on surface cleaning.” She added, “There is really no evidence anyone has ever gotten Covid-19 by touching a contaminated surface.”

In the early days of the pandemic, many experts believed that the virus was mainly spread via large respiratory droplets. These droplets are too heavy to travel long distances in the air, but they can fall onto objects and surfaces.

With that in mind, it made sense to focus on scrubbing every surface. “Surface cleaning is more familiar,” said Dr. Marr. “We know how to do it. You can see people doing it, you can see the clean surface. I think it makes people feel safer. “

Over the past year, however, it has become increasingly clear that the virus mainly spreads through the air – in both large and small droplets that can stay in the air longer – and that cleaning door handles and subway seats is little for safety who contributes.

“The scientific basis for all of these surface concerns is very slim – slim to none,” said Emanuel Goldman, a microbiologist at Rutgers University, who wrote last summer that the risk of surface transfer was exaggerated. “This is a virus that you get by breathing. It’s not a virus that you get by touching it. “

Updated

April 8, 2021, 1:03 p.m. ET

The CDC previously recognized that surfaces are not the primary way the virus spreads. But the agency’s statements this week went further.

“The most important part of this update is that it clearly communicates the correct, low-risk surfaces to the public, which is not a message that was clearly communicated over the past year,” said Joseph Allen, a building security expert at Harvard TH Chan School of Public Health.

Intercepting the virus from surfaces remains theoretically possible, he noted. But many things have to go wrong: lots of fresh, infectious virus particles have to be deposited on a surface, and then a relatively large amount has to be quickly transferred to a hand and then to a human’s face. “Presence on a surface is not the same as risk,” said Dr. All.

In most cases, cleaning with simple soap and water – in addition to washing hands and wearing masks – is enough to keep the chances of surface transfer low, according to the CDC’s updated cleaning guidelines. In most everyday scenarios and environments, people don’t need to use chemical disinfectants, according to the agency.

“I think this is very useful for telling us what not to do,” said Donald Milton, an aerosol scientist at the University of Maryland. “It doesn’t help to spray a lot and spray chemicals.”

However, the guidelines suggest that the area where someone with Covid-19 was in a given location on the last day should be both cleaned and disinfected.

“Disinfection is only recommended indoors – in schools and at home – where a suspected or confirmed case of Covid-19 has arisen within the past 24 hours,” said Dr. Walensky during the White House briefing. “In most cases, fogging, fumigation, and large-area or electrostatic spraying are not the recommended primary methods of disinfection and pose several safety risks.”

The new cleaning guidelines do not apply to healthcare facilities that may require more intensive cleaning and disinfection.

Saskia Popescu, an infectious disease epidemiologist at George Mason University, welcomed the new guidance, which “reflects our evolving data on transmission during the pandemic.”

However, she noted that it is still important to clean regularly and maintain good hand washing practices in order to reduce the risk of infecting not only the coronavirus but also other pathogens that may be left on a certain surface.

Dr. Allen said the school and business officials he spoke to this week have expressed relief at the updated guidelines that will allow them to roll back some of their intensive cleaning programs. “This gives many organizations a chance to spend that money better,” he said.

Schools, businesses and other institutions that want to keep people safe should turn their attention from the surface to air quality and invest in improved ventilation and filtration.

“This should be the end of the deep cleanse,” said Dr. Allen, realizing that the misguided focus on surfaces created real costs. “It has resulted in closed playgrounds, it has resulted in nets being removed from basketball courts, it has resulted in library books being quarantined. It has resulted in entire missed school days for a thorough clean. It led to the fact that you can’t share a pencil. So this is all hygienic theater, and it is a direct consequence of the surface transfer not being properly classified as low risk. “

Roni Caryn Rabin contributed to the coverage