Infection Prevention FAQ with Jim Flieler

By: Jim Flieler, Vice President of Sales, Charlotte Products Ltd.

The questions I hear from customers and end users over and over again is, “Do I really need to let the product remain wet for this long?  What if I shorten the dwell  time ?” And over and over again, I answer, “Anything less than the listed dwell time on the product label is a failure.” 

So set your clock and wait. To achieve true infection prevention, you must respect the dwell time. It’s simple advice, but it’s essential for facility health and safety. Here I’d like to share some frequently asked questions and best practices to help your facility better understand the vital role of dwell time in disinfection practices.

Where can I find the dwell time?

The label is the law. The label on your disinfectant product tells you everything you need to make sure you are disinfecting that surface, including your dwell time. 

Do I really need to follow all those directions?
Yes you do. Any other way is a failure.

What is the purpose of a dwell time?

Dwell time, also called contact time, is the amount of time the disinfectant needs to remain wet on a surface to properly disinfect. This is the time that it takes for the disinfectant product to achieve the kill claims on the label. Dwell times may differ for different types of microorganisms and can range from anywhere between a few seconds to up to 10 minutes. That is why you will want to know the pathogens you are targeting and respect the corresponding dwell time. 

Does the surface have to remain wet the entire dwell time?

Yes, the surface must remain wet for the entire dwell time. Anything else is a failure.

If I cut the dwell time in half, will the disinfectant still work? 

No. You cannot guarantee that your surface has been disinfected if you do not respect the full duration of dwell time. You have to set your clock and respect the dwell time. If it says five minutes and you wait four, you are failing.

What if my product has a longer dwell time? How can I keep a surface wet for up to ten minutes? 

Dwell time can be as long as ten minutes with some products. We recommend applying more diluted product on a surface to ensure it stays wet longer. Both humidity and air temperature play a factor. It can be a challenge to keep a surface wet for that amount of time if you do not follow a regular cleaning route routine. We suggest following standard operating procedures (SOP). They help establish a cost effective quality assurance cleaning protocol in any type of facility. Ensure you pre-clean areas that require disinfecting, then apply your disinfectant to these surfaces and then go about cleaning other areas of the room, allowing the disinfectant to dwell. This addresses current labor costs while achieving disinfection.

Does temperature and humidity impact dwell time? 

Yes, the weather and humidity in the air can impact your ability to achieve dwell times. Drier and hotter weather means your product will dry faster, so you will need to apply a little more to ensure you are following dwell times. 

Does the speed of application impact dwell time?
This is common sense. If you go through a room very fast, you will often leave less product on the surface. If you take your time, you apply more, and the surface will stay wet longer. 

Do you recommend a specific type of application to ensure dwell times?

I always recommend the traditional pump-up sprayer for applying disinfectant to high-touch surfaces. Since the COVID-19 pandemic has brought on the prevalence of new application methods for disinfectants, including sprayers, foggers and misters, dwell time must be reinforced as a fundamental step in any infection prevention plan. 

The five critical security elements of disinfecting provide best practices for disinfectant use, which should serve as the foundation for any training program focused on infection prevention. Each of these elements is equally as important in contributing to healthy, safe spaces.  We’ve published FAQ for each step HERE. 

Have an additional question? Contact an expert at Charlotte Products to ask your question, or learn more about our infection control programs at