How to safely disinfect surfaces from the COVID-19 virus

Disinfectants can be useful for stopping the spread of COVID-19 in certain situations, but there is an overwhelming amount of confusing information out there. That’s why we’ve partnered with indoor air expert Dr. Delphine Farmer, a Chemistry professor at Colorado State University, to answer the most frequently asked questions about how to disinfect surfaces safely.  

The virus that causes COVID-19 can last on surfaces for hours or even up to days. Many workplaces and private homes have started new cleaning routines. However, using the wrong cleaners can cause more problems than it solves, such as accidentally creating unintended byproducts – chemicals that weren’t in the original cleaner but are produced by chemical reactions with dirt on the surface or pollution in the air. Most importantly, while viruses can remain on surfaces for long periods of time, airborne transmission is the likely culprit for most COVID cases. Doctors initially thought that COVID was transmitted via surfaces, but we are learning that airborne transmission is a much bigger risk.

This guide is for people working or living with high-risk individuals or in crowded areas with frequently touched surfaces where disinfecting surfaces can be useful.

Q: COVID-19 is airborne, so should we still be cleaning surfaces? 

Scientists believe that airborne transmission is the most common way that people catch COVID-19. While it’s a great idea to keep work and home spaces clean, cleaning surfaces is unnecessary for the purpose of preventing the transmission of COVID-19 unless you work with particularly vulnerable people or high-touch surfaces. There are two situations in which surface cleaning can be beneficial:

• Places with vulnerable groups, such as those who are immunocompromised, the elderly, and people in healthcare facilities

• Very crowded spaces with high-touch areas like door handles and faucets

Scientists call excessive cleaning ‘hygiene theater.’ It might smell clean or make you feel safer, but it doesn’t actually reduce your chances of getting COVID-19 in most environments.

Q: How do I know which cleaning products work?

The EPA (US Environmental Protection Agency) has a ‘List N’ of cleaning products that work to destroy the viruses that cause COVID-19 on their website. There are lots of options. Some require products to be on the surface for up to 10 minutes, others only 30 seconds. For example, products with bleach or sodium hypochlorite do destroy the virus responsible for COVID-19, but they require up to 30 seconds of contact time.

Q: Are cleaning products dangerous?

Sometimes. If misused (e.g. not mixing the product with water exactly as specified on the container instructions), cleaning products can be dangerous.

Some disinfectants like bleach and hydrogen peroxide react with food debris and material on floors or surfaces and produce a toxic array of byproducts that are released into the air. These reactions are fast, so it’s never a good idea to hang out with disinfectants for longer than necessary – and always ventilate the room when cleaning. Crack open a window, and turn on a bathroom or kitchen fan.

Q: If one cleaner is good, two must be better, right?

No! Not only is this unnecessary, but mixing cleaners can cause all sorts of chemical reactions and toxic byproducts. For example, mixing bleach and vinegar creates toxic chlorine gas, and mixing bleach and pine- or lemon-scented cleaners will make an array of chemicals that produce tiny particles in the air that enter your lungs and may cause tissue damage. If you must use a disinfectant, then only use one at a time and make sure that it is thoroughly dried out and that you can’t see or smell it before using another. And always ventilate the room.

Q: Should we disinfect groceries and packages before bringing them into the house?

Don’t bother:  there is no evidence that mail or grocery delivery causes COVID-19 transmission, so skip the cleaning and reduce your exposure to cleaning products and their risks.

Q: Are Clorox wipes enough? Is there anything specific I need to do with the wipes to make sure they are effective?

Yes, Clorox wipes are effective – many germicidal wipes are approved by the EPA to kill the COVID-19 virus. After wiping down a surface, most products need 30 seconds before the virus is destroyed, but some need up to 10 minutes. You don’t need to do anything except wait, and definitely don’t add any other products! Step away while you are waiting and ventilate the area if you can – it’s never a good idea to breathe in disinfecting chemicals.

Q: I know UV light kills the virus, so how long should I be leaving things outside for them to be safe?

Certain types of UV light do kill the virus, but sunlight doesn’t have a lot of that type of light. That’s actually a good thing, as too much UV light can cause skin cancer and other problems. But since surfaces aren’t important transmission pathways for COVID-19, don’t worry about leaving groceries or packages outside. Just keep your distance and wear your mask when the person delivering packages gets near your house.

Q: Are any disinfectants dangerous to breathe in? Are there natural alternatives to Clorox wipes or bleach?

Yes, many disinfectants are dangerous to breathe in if you spend too much time with them. Common cleaning agents like bleach, quaternary amines, and hydrogen peroxide can all cause negative health effects if you breathe in too much of them. So, it is always important to follow manufacturer instructions and ventilate the space when you use them. Currently, there aren’t any ‘natural’ products on the EPA List of tested and approved products for the COVID-19 virus, but the list gets updated frequently, so keep an eye out for your favorite natural cleaner.

Q: How about soap and water? Does that work?

Yes!  Cleaning with simple soap and water for 20 seconds does wonders. Soap causes the virus to fall apart. Soap and water are cheap, fast, effective, and safe. Using soap will not create any toxic byproducts in the air.