Understanding Disinfectant Kill Times

August 04, 2020

If You're Not Following the Instructions, You May Not Be Disinfecting

We know frequent disinfection, especially of high-touch surfaces, has always played a role in ensuring the safety of your staff and customers, and right now it's more important than ever. We also know that not all people understand that if you're spraying disinfectant and immediately wiping it down, it's probably not doing the job it's meant to.

FaciliSafety is here to help. We're making it easy to understand what to look for in a cleaning product and why it's so important to follow the directions on your cleaning supplies.


What's a "Kill Time"?
A kill time (or contact time) is the time it takes for a disinfectant to kill the bacteria or virus it claims to be effective against. Every disinfectant has them. If they're not on the label, they should be available from the manufacturer.


How Long Does My Disinfectant Take to Kill Germs?
That depends - it can take from 30 seconds to 10 minutes. Germs have different kill times because some are easier to kill than others, and the active ingredient in the disinfectant works differently on different germs. One disinfectant can have several different kill times.


Example: MadaCide-1
EPA Registration Number:  1839-83


Contact Time


30 seconds

Avian Influenza A strains H3N2 and H9N2, Human Coronavirus, SARS associated Coronavirus

2 minutes

Hepatitis B (HBV), Hepatitis C (HCV)

5 minutes


What Are the Kill Times for SARS-CoV-2?
That depends. Because COVID-19 is a novel virus, many disinfectants are still undergoing testing against it.

A search of the EPA's List N tool might turn up only a handful of disinfectants effective against SARS-CoV-2 specifically, but that doesn't mean other disinfectants aren't effective. The list also includes disinfectants registered to be effective against similar human coronaviruses or viruses that are harder to kill. The EPA also recommends you "follow the disinfection directions and preparation for the [applicable] virus".

[insert screen shot from List N tool link above. I included one, but recommend Joel grab one from the same link and draw a prettier circle around the column in my example  - maybe even blur out the product info]


Read the Label. Always.
No matter what germ you're trying to kill, always - always! - follow the instructions on the label. If the disinfectant is not mixed properly, applied correctly, or is wiped away too soon, the germ may not be effectively killed. That means it can be picked up by the next unsuspecting hand that touches it.


When in Doubt, Ask for Help
If you need help choosing or sourcing the right disinfectant, give us a call. We'd be happy to help you find exactly what you need.


3 Basic Steps for Proper Cleaning of Hard Surfaces

1. Clean with soap and water.
  • Soap and water don't kill germs. It helps reduce the spread of germs by removing them from handles, counters, doors, handrails, bathroom surfaces, just like handwashing removes germs from your hands.
  • Visibly dirty surfaces should be cleaned with soap and water before using disinfectants.
      2. Disinfect
      • Like hand sanitizers, disinfectants provide a convenient way to kill germs without soap and water. Disinfectants should not be a substitute for routine cleaning of hard surfaces.
      • Always follow directions on the label.
        TIP: Choose a disinfectant with a contact (kill) time that meets the level of traffic for surface you're cleaning. For high-traffic areas, opt for shorter contact times.
      3. Repeat steps 1 and 2 as needed daily.
      • Clean any visibly dirty surface with soap and water.
      • Disinfect surfaces between washing, prioritizing high-touch surfaces.


      The Difference Between Cleaning, Sanitizing, and Disinfecting
      We might use these words interchangeably, but they are distinctly different when it comes to the products we choose to clean our spaces. Keep these definitions from the CDC in mind when updating or creating your facility's plan for cleaning.

      • Cleaning removes germs, dirt, and other impurities from surfaces, but doesn't necessarily kill them.
      • Sanitizing lowers the number of germs on surfaces or objects - either by killing them or removing them - to a safe level, according to public health standards or requirements.
      • Disinfecting kills germs on surfaces or objects.

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