Biohazard Cleaner Warns We Often Miss This Critical Step In Disinfecting Surfaces

To reduce your chance of infection, the US Centres for Disease Control and Prevention (CDC) recommends cleaning areas you touch often, like doorknobs, sinks, and toilets.

But cleaning a surface isn't the same as disinfecting it. The cleaning process involves scrubbing an area with soap and water, while disinfecting means applying a chemical to kill germs.

"The most important step is the cleaning step," Cory Chalmers, the CEO of the professional cleaning service Steri-Clean, told Business Insider.

His team specialises in biohazard cleaning for sites contaminated with infectious diseases. For the past month, the team has dedicated itself almost exclusively to scrubbing down places contaminated by the new coronavirus. That includes homes, cruise ships, offices, factories, and fast-food restaurants.

"A lot of people spray a surface and then wipe it around right away," Chalmers said. "But you're not letting the disinfectant do its job."

That's because dirty surfaces are coated in clusters of germs called biofilm that resist disinfectants. These germs have to be removed before a chemical can effectively kill off any lingering viruses or bacteria.

Chalmers said the first step in the cleaning process should be putting soap on a rag or paper towel and then folding the towel into quarters. The towel will lift the biofilm off the surface so only residual germs are left behind.

After you've wiped down a small surface – a couple of square feet – flip the towel over and use the other side, then turn it inside out and use the remaining quarters.

"People sometimes will walk around the house with the same rag, cleaning all the surfaces. That doesn't do anything because now they're just spreading the germs around," Chalmers said. "Once that towel or rag that you're using is full of germs, it's not going to absorb anymore."

After the surface is clean, you can apply a disinfectant spray or wipe.

Chalmers said the back of every disinfectant bottle was marked with a "dwell time" – how long the disinfectant needs to sit on a surface before it kills germs. Some disinfectants take 10 minutes, while others only about 30 seconds.

The virus lives longer on certain surfaces, like glass

Depending on the type of surface, it's possible to let the coronavirus die on its own. Research from the University of Hong Kong suggests that the novel coronavirus can live for three hours on printing and tissue paper but for two days on cloth.



The virus tends to survive for much longer on glass and paper money: about four days. But its lifespan also depends on temperature and humidity.

The Hong Kong researchers found that the coronavirus lasted up to two weeks in a test tube under 39 degrees Fahrenheit (4 degrees Celsius), but just one day under 99 degrees Fahrenheit (37 degrees Celsius). A group of Beijing researchers also determined that high temperature and high humidity could reduce the virus' transmission.

Since there's still more research to be done, Chalmers said cleaning and disinfecting was a safer method than waiting for the virus to die.

"When you're dealing with a new strain like this, we really don't have all the answers," he said. "I don't think we have enough factual data to know that closing up a building or an office or a room will kill that virus."

That's also why he recommends being extra cautious when wiping things down – or hiring a service to do it for you.

"There are so many companies out there from landscapers to plumbers to exterminators that are all claiming they're experts and they're going to disinfect your house," Chalmers said.

"Ask them how they're doing it. What's the process? Are they cleaning first, then applying the disinfectant? Are they testing? If they're doing all three of those, you should be safe."

Source