Update: When to Disinfect, and When to Not

April 5, 2021
By Jason Marshall

In light of CDC’s guidance issued on April 5, 2021, only a few situations call for cleaning more frequently or disinfecting in shared spaces. These conditions are: 

• Communities with a high transmission rate of COVID-19
• Communities with a low number of people wearing masks and infrequent hand hygiene
• Spaces that are occupied by certain populations, such as people at increased risk for severe illness from COVID-19

For most scenarios, you do not need to disinfect all surfaces all of the time.

Cleaning, whether it be an office building, school or home, will help bring the level of contamination to a safer level. The best way to prevent the spread of COVID-19 still remains the basics of wearing masks, washing hands and socially distancing.

Always Clean Before You Disinfect

If you do not remove the dirt and grime first, the microorganisms will be harder to reach and destroy because the soil provides a “shelter” for the organisms. The dirt can also interfere with the effectiveness of the disinfecting chemicals, rendering them less effective. Cleaning must come first.

Select Safer Disinfectants

If you have completed the first step of cleaning surfaces and are in a situation where disinfection is the right next step, make sure you are using a disinfectant that contains safer active ingredients: 

• Citric Acid
• Caprylic Acid
• Hydrogen Peroxide
• L-Lactic Acid
• Ethanol
• Isopropanol
• Peroxyacetic Acid
• Sodium Bisulfate

Many of the traditional disinfecting products (like bleach or quaternary ammonium compounds, often referred to as quats) have been found to contribute to health hazards, such as triggering asthma. In cases when these disinfectants are mixed with certain cleaning chemicals, even more toxic substances can form which can lead to death.

Your selection of safer disinfectants doesn’t need to be a hard process. The EPA List N list offers many options to choose from. If you combine this list with EPA’s Design for the Environment (DfE) safer active ingredients for disinfecting chemicals, then you don’t have to hunt very hard to find something that has been documented to work and to be safer. You can also view the TURI list of safer disinfecting products.

In addition to products with safer active ingredients, there are other options that may not meet all of the EPA requirements but have an improved safety profile when compared with traditional disinfectants. These include:

• Dry Steam Vapor
• Hypochlorous Acid generated by:
  • Electrolyzed water systems
  • Chemical (NaDCC) tablets in water
• Aqueous Ozone
• UVC Light

Can All Purpose Cleaners Disinfect?

While the efficacy of all-purpose cleaners for disinfection has not yet been validated, the ability of these products, which function by breaking down fatty, grease-like soils, to breakdown the lipid (fatty) exterior layer of the SARS-CoV-2 virus suggests that there is likely to be some reduction in the viability of the viruses. Learn more about the TURI Lab's ongoing testing of all-purpose cleaners.

Safety First

No matter what products you choose to use in your disinfecting process, remember that safety still matters. You must use the method as directed. The key factors are: 

• Use the correct concentration as indicated on the label
• Spray disinfectants on all targeted surfaces (not in the air) until the surface is visibly wet
• Keep the disinfectant on the surface for its directed contact time to optimize disinfection
• Spray disinfectants only when no one is present in the space, starting with the area farthest from the exit

No matter how safe your disinfectant or method is, you should still wear the proper protective equipment (gloves, goggles) and provide adequate ventilation (use a fan and open doors and windows).

As you return to occupying spaces with people who are not part of your “bubble,” mask wearing, handwashing and social distancing remain essential practices. Being careful to also maintain a clean environment can help further ensure that everyone is, and feels, safer.