Understanding Dwell Time and Why It’s Important

Posted September 11, 2020

Dwell time (text) and spray bottle (image)

The words “dwell time” have been thrown around quite a bit more this year than in any other year in the past. Dwell time, or contact time, is the appropriate amount of time that a disinfectant has to remain visibly moist on the surface being cleaned to effectively kill the germs, viruses, or bacteria you’re combating. One common disinfecting mistake is spraying the disinfectant and wiping it away without giving it any time to work its magic.

Without adhering to the right dwell time, the disinfectant won’t have enough time to do its job, which is to disinfect and kill the targeted pathogen. While the disinfectant may kill some of the bacteria or germs on the surface, it won’t be nearly as effective as it would be if you had followed the suggested dwell time. In many cases, this bad habit leaves behind surfaces that aren’t disinfected at all. So, let’s clear up some of the mystery behind dwell times:

What is the right dwell time?

The right dwell time will vary depending both on the disinfectant you’re using and the goal you’re trying to achieve. For example, a regular household disinfectant that’s meant to kill germs that cause the common cold may have a much different dwell time than a stronger disinfectant that’s approved for use against the coronavirus. And the dwell time for different disinfectants can range drastically, lasting anywhere from a mere 30 seconds to 15 minutes.

But there’s good news: you don’t have to do the math or work too hard to find the answer. The dwell time of your disinfectant should be listed right on the label! If it’s not, you can find the dwell time by searching for your disinfectant on the Environmental Protection Agency’s (EPA) website. Disinfectants approved for fighting fast-spreading viruses like COVID will likely have shorter dwell times. This may seem counterintuitive, but trust the process; a single-minute dwell time simply means less time waiting around and more time protecting your loved ones, employees, and customers.

Which disinfectants should I be using?

If you already have disinfectants at home, check the label or the EPA’s website to see if they are approved for use against COVID-19. Otherwise, finding the right disinfectants has been a bit challenging for many over the last few months. Just like finding toilet paper was in April. Clorox and Lysol are two of the most common household disinfectants and they are generally effective against COVID (always double-check the specific product before use), but if they have a longer dwell time, they may not be your best option.

One favorite this year has been Diversey’s Oxivir TB Wipes. These have a dwell time of one minute and are approved for use against COVID pathogens. While the shorter contact time makes effective disinfecting easier, there’s one other thing to keep in mind: make sure the surface doesn’t dry before the dwell time is up. If it dries, you’ll have to reapply. Diversey wipes (when used appropriately) tend to keep the surface wet for the required dwell time, so this shouldn’t be a problem here if you can get your hands on some.

What is the shelf-life of diluted disinfectants?

While many effective disinfectants come ready to use, others may need to be diluted with water. These are typically used in the old-school-style of disinfecting that involves filling a bucket with the diluted disinfectant and dipping towels or rags in it. They’re effective for a variety of surfaces, but they have a short shelf-life once you alter them. Your disinfectant’s label should give you the right time frame that you have to use it in before disposing of what’s left.

Are dwell times really that important?

When it comes to cleaning and disinfecting, there are plenty of opinions and suggestions floating around. Dwell time isn’t one of them. Following the appropriate dwell time is a requirement for effective disinfecting. The EPA puts in a lot of work to test and confirm the effectiveness of different disinfectants so that we don’t have to. If the end goal is thorough and effective disinfection of any surface, letting the disinfectant dwell for as long as the label specifies is crucial.

Corvus Janitorial Systems

While we’re sharing space with COVID-19, following the appropriate cleaning and disinfecting procedures is more important than ever. If figuring out the ins and outs of effective office or business cleaning feels overwhelming, we’re here to help. We understand the appropriate dwell times of common disinfectants, use high-grade chemicals and procedures, and offer a variety of advanced services specifically designed to fight fast-moving viruses like COVID.

If your workplace is in need of commercial cleaning and/or disinfecting services, contact your local Corvus Janitorial Systems team for a free consultation and quote.

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