As a Technical Services Specialist for Contec, Inc. during this era of heightened awareness for cleanliness and contamination risk, I am increasingly asked about the best way to clean and disinfect. One of my favorite, simplest explanations is this: “When a wipes or liquid product label makes the claim that what’s inside is 99.9% effective…you only get that result if you precisely follow the directions! This is because, while spraying and wiping can be an effective way to remove microorganisms, the contact time of the disinfectant is what will provide for that microbial kill."
Perplexed? This explanation sometimes yields a blank stare because many are not aware of the importance of contact/dwell times. Most people want to wipe or spray and go about their business with little thought behind how long the treated surface needs to stay wet. But, the plain truth – especially now – is that we can’t take for granted all the testing and validating behind a “99.9% effective” statement. Years of work went into the manufacturer’s proof of their EPA-registered claims. Fortunately, it only takes a few seconds to understand how to best use these products!
My strong suggestion to read the entire label might elicit a reply such as, “I don’t have a magnifying glass nearby.” Or, “I could read a novel in less time.” So, while it is important to read the entire label, there are a few shortcuts that can greatly assist you should your time (or your eyesight) be less than you’d like them to be:
1. Safety precautions – some disinfectants have certain ingredients in them that require disposal and/or use with personal protective equipment (PPE). The stronger the disinfectant, the more PPE is required.
2. Directions for use – here is where you will learn:
a. Whether the product is a high-level disinfectant (sporicidal), intermediate disinfectant (bactericidal, viricidal, and tuberculocidal), low-level disinfectant (sanitizer), or germicidal disinfectant with specific contact time requirements.
b. How to use the disinfectant correctly, and if it cleans and disinfects in “one-step” – there are some disinfectants available, such as bleach, that require the surface to be cleaned prior to use. Bleach is not considered a cleaner and disinfectant. Cleaning prior to disinfection would also be required with a surface that is heavily soiled.
3. Contact (wet/dwell) time – how long the surface must remain wet to be effective (that “%ge” touted on the front of the product label).
a. Contact time is important because the disinfectant won’t work the way it is intended if the contact time is not met. For example, if the label reads that the surface must remain wet for 60 seconds, then you need to wait that long before wiping away any residual moisture! Otherwise, that “99.9%” efficacy claim is simply not achievable.
b. Product labels also commonly note the organisms against which they are proven effective, as well as the required contact time for each. If the surface is not wet for the specified contact time, you will not achieve efficacy against those microorganisms! Also, if a disinfectant dries too quickly, you should reapply the disinfectant and keep the surface wet for the specified contact time.
Of all of these, I like to stress that contact times are the most importing thing to note. Reading and understanding what is on the label will help insure you are cleaning and disinfecting properly, which in turn will help you maintain the safest environment possible!
Disinfectants that are effective against COVID-19 are available on the EPA website. Click Here
(use the search bar to find your disinfectant brand name)
Senior Technical Services Specialist