A chemist’s guide to disinfectants

A chemist’s guide to disinfectants

“You’re a chemist, right? We’re almost out of wipes. Do you have any ideas on what else we could use to disinfect?” As supplies in grocery store cleaning aisles dwindle, chemists and other people with science backgrounds are fielding questions like these from friends and relatives about what they can use to kill the novel coronavirus, SARS-CoV-2.

Although manufacturers of disinfectants are doing all they can to keep up, demand is through the roof, and some raw material supply chains are strained. So how should you advise your friends and family on their available options?

C&EN constructed this guide to explain the ingredients in disinfectants and help you give good advice. The most important thing is to read the labels. The US Environmental Protection Agency regulates disinfectants used on hard and soft surfaces under its authority to regulate pesticides. The agency vets and stands behind the efficacy promises on the labels, as long as you follow the instructions.

Labels offer guidance on how to use disinfectants safely—for instance, in a ventilated area—and they explain which cleaning products shouldn’t be mixed with other chemicals. Interactions you might not expect can create toxic gases or make the mixture stronger or weaker than anticipated.

Even the type of cloth you use when cleaning hard surfaces might alter how a disinfectant works. For instance, paper towels can decompose after long soaks in some disinfectants and deactivate others. The fabric in wipes is specially formulated to be unreactive, so experts advise that you don’t try to make your own premoistened wipes. Instead, you should spray a liquid disinfectant onto the target surface, let it sit for at least the “dwell” or “contact” time listed on the label, and then wipe dry or let the liquid evaporate. For soft surfaces like cloth or food, experts suggest different cleaning methods.

SARS-CoV-2 is an enveloped virus, which means it is surrounded by a lipid membrane. That’s good news, because a wide variety of disinfectants can disrupt lipid membranes, killing the virus they were protecting. Few disinfectants have been rigorously tested against SARS-CoV-2 in the lab, but the EPA maintains a public database of products it recommends for use against SARS-CoV-2 on the basis of their proven efficacy against similar viruses. Users can search this list by product name, active ingredient, type of product, and more. Users can search EPA's database, called List-N, by product name, active ingredient, type of product, and more.

Disinfectant wipes and sprays used to clean hard surfaces are currently scarce, so we’ve curated the list below to describe the chemicals used in those products. You can use this information as a cheat sheet while you read the labels on the products you can find.