The coronavirus that has infected more than 100,000 people around the world can lurk for hours on doorknobs, handrails, keyboards, elevator buttons and other hard surfaces, just waiting to be passed on to someone else. "By touching a surface or object that has the virus on it and then touching their own mouth, nose or possibly their eyes," a person could become ill with COVID-19, the respiratory disease caused by the coronavirus, warned the Centers for Disease Control and Prevention (CDC).
That makes it imperative to thoroughly clean shared workspaces when a known or suspected exposure has been introduced by an employee or visitor. But what is the best way to disinfect a contaminated space? And how clean is clean enough? Employers are figuring it out as they go.
On March 2, the Wildhorse Casino in eastern Oregon cleared out thousands of customers within hours of learning that an employee had tested positive for COVID-19. The casino and adjacent hotel, movie theater and arcade closed for two days of deep cleaning with special disinfecting equipment typically used by hospitals.
That same week, the North Star Mall in San Antonio closed for 24 hours of deep cleaning after learning that a person who tested positive for COVID-19 had visited several stores and the food court. A nearby elementary school was also closed for cleaning after it was discovered that one of the teachers worked at the mall.
Nike went one step further that week and closed its world headquarters in Beaverton, Ore., for two days of deep cleaning "out of an abundance of caution" after learning of a COVID-19 case in a neighboring town.
Closing Shop Not Possible for All Employers
However, shutting down an entire business for a deep clean is not a universal response to coronavirus exposure. It is not among the CDC's recommendations, and it may be increasingly impractical as the virus becomes more widespread and exposures multiply. Businesses are more likely to announce general cleaning protocols and follow them discreetly when an exposure happens.
A person attended a political conference in Maryland's National Harbor in late February and days later was diagnosed with COVID-19. The event was held at the Gaylord National Resort, operated by Marriott International, and several prominent elected officials who were there have quarantined themselves voluntarily for 14 days. But the resort did not close. On March 10, Marriott International issued a statement outlining general steps it has taken to clean common areas and seal off contaminated guest rooms. The hotel chain and National Harbor did not comment further.
Heavily used airports and transit systems continue to operate 24/7, with more frequent swabbing of handrails, doorknobs and elevator buttons. Even so, New York's Metropolitan Transportation Authority is advising people to avoid the subway if possible and asking local employers to stagger start times to reduce congestion.
What's most important when a workspace is contaminated is to methodically track the steps of the infected person and clean any shared surfaces they touched with effective cleaning solutions, said Andrew Rosen, vice president for sales at Commercial Cleaning Corp., a New Jersey cleaning contractor that's been inundated with calls recently.
"You want to know where that person was in that office and then go in and clean top to bottom, disinfecting all the high-touch areas," Rosen said. "If an area is grimy, clean it first with soap and water. Make sure there's no dust, nothing on the surface, before you take a wipe and disinfect. Make sure the disinfectant stays on for the kill time. You know those Clorox or Lysol wipes? Most of them have a four-minute kill claim. That means the surface needs to stay wet for four minutes."
For added security, Rosen said, some employers follow up with an electrostatic cleaning, using gun-like devices that spray a mist to envelop all surfaces in disinfectant and that have been seen in a lot of coronavirus cleanup photos. Rosen sells the devices through a separate company, and has shipped several to Washington state, where the initial U.S. cases were reported. He's sold out now and doesn't expect any new supplies until July. "They're made in China," he explained.
Federal Guidelines Issued for Coronavirus Cleaning
For businesses that prefer to handle matters themselves, several federal agencies recently released post-contamination cleaning guidelines.
Immediately following an exposure, the CDC recommends closing off areas used by the ill person and waiting 24 hours or as long as possible before beginning to clean and disinfect, opening doors and windows to improve air circulation.
It is not known exactly how long the novel coronavirus can stay alive on a surface, said Dr. Jay C. Butler, deputy director for infectious diseases at the CDC. "Under real-world situations, it's probably minutes, but it could be days," he said. "It depends on the temperature, humidity and the type of surface."
After cleaning off any obvious dirt from the area, businesses should disinfect shared spaces using diluted household bleach, alcohol solutions with at least 70 percent alcohol, or household disinfectants effective against the coronavirus. Cleaning crews should wear gloves and wash their hands immediately after removing the protective gear.
The Environmental Protection Agency (EPA) has listed disinfectants currently thought to be effective and urges users to follow the directions on the product label, since some disinfectants require more time to kill the virus than others. "If the directions for use for viruses/virucidal activity list different contact times or dilutions, use the longest contact time or most concentrated solution," the EPA advised.
The Toughest Cleaning Challenges: Airplanes and Cruise Ships
Some cleaning jobs are bigger than others. It's hard to imagine a more complicated disinfecting challenge than an airplane or cruise ship that has carried infected passengers. Both industries have long-standing protocols for cleaning, refined through years of Ebola, SARS and other health crises and guided by CDC instructions for ships and airplanes.
Several airlines, including Delta, United and American, have issued statements regarding updated cleaning protocols, vowing to remove from service any flights that have carried passengers with COVID-19 so that the planes can be thoroughly cleaned and sanitized.
Princess Cruises has gone even further. In late February, the cruise line issued a high-profile request for proposals, asking for bids "for an extensive out of service cleaning, disinfection and refurbishment" of the Diamond Princess, the ship that became notorious for its excruciating weekslong quarantine in Yokohama harbor in Japan. Proposals were to address how companies would clean a long list of designated areas, including staterooms, galleys, deck areas and handrails, the medical center, and entertainment venues on the 18-deck ship where nearly 700 people tested positive for COVID-19. The proposals are to be reviewed by the CDC and World Health Organization as well as Princess. So far, no contract winner has been announced. Princess Cruises did not respond to questions about how many bids it has received.