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On the packaging for most steam mops, you’ll see claims like “Sanitizes Bacteria 99.9 percent” or “Eliminates 99.9 percent of germs and bacteria.”
Are these claims overblown—and do they apply to viruses such as the coronavirus?
We reached out to microbiologists to find out. The short answer: Technically, yes. Steam can kill pathogens, including the coronavirus.
“Because heat and steam will kill viruses, such mops will certainly be able to kill viruses,” says Paula Cannon, Ph.D., professor of microbiology at the Keck School of Medicine of USC in Los Angeles.
But the real question is whether it makes sense to use a steam mop to disinfect. The answer is not really.
Cannon explains that viruses in general are very susceptible to heat.
“Viruses come ‘shrink-wrapped’ in a layer of fat that helps them to survive in our bodies, by acting as a type of stealthy covering,” she says.
The spikes on the outside of this fat layer allow it to latch onto and enter your bodies’ cells. However, this layer of fat is quite fragile and can easily be broken down by high temperatures.
“You can think of it as being melted, if you like, by high temperatures,” Cannon says. “And once that happens the virus particle is no longer intact and can no longer infect anything.”
But how high does the temperature need to be? According to Philip M. Tierno, Ph.D., a clinical professor of microbiology and pathology at New York University, most pathogens, including the coronavirus, will die at 212° F.
Steam mops can get up to that temperature, but you’d have to hold the mop in place for at least 10 minutes at a time for it to be effective. And that’s the catch: Steaming your floor for minutes at a time can kill pathogens—and also damage your floor. (Steam can pop tiles and force its way under wood floor boards and warp them.)
Furthermore, some steam mops require you to manually pump them to generate steam, which means the temperature may fluctuate, making it hard to tell whether you’re really killing any germs.
The Centers for Disease Control and Prevention does not recommend disinfecting floors in general to prevent the spread of the coronavirus even if someone in your home is sick with COVID-19. But it does advise disinfecting any areas that may have blood, stool, or bodily fluids on them—so maybe the bathroom floor.
But while a steam mop could be effective for that, you’re better off wiping your floors with an Environmental Protection Agency-registered household disinfectant, such as a bleach solution for nonporous flooring or Lysol Disinfectant Spray for wood floors. You may also be able to use other common household cleaners that kill germs. (Check to make sure the product is recommended for use on the type of flooring you have.)
Top-Performing Steam Mops
They may not be practical for disinfecting, but a good steam mop can make quick work of cleaning sticky messes on floors. Here are the top-performers from Consumer Reports’ tests. For more information, see our steam mops buying guide and ratings.
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