In recent years, some Americans concerned about the effects that harsh cleaners have on the environment and on the human body have switched to household products marketed as green, eco-friendly, nontoxic or natural. The concern is not unwarranted — the chemicals in some cleaning products can cause eye, skin or respiratory irritation — though it can be difficult for the average consumer to determine whether green alternatives are safe and effective.
And when it comes to killing the coronavirus, green products might not be enough. The Environmental Protection Agency released a database (List N) of products proven to be effective against the coronavirus that contains few green cleaners. This doesn’t mean you have to toss your natural products, but you do have to be judicious about where and when you use them. Here’s what you need to know.
Before going further, it’s important to understand the difference between cleaning and disinfecting. Cleaning refers to the removal of germs and dirt from surfaces, but it does not kill pathogens; if any are left behind, they remain active.
Disinfecting does kill germs on surfaces — if you do it properly. That’s what you want if the coronavirus is in your household or if you suspect that someone in your home has been exposed to it. The virus can live for up to three days on some surfaces, such as plastic and stainless steel.
The EPA’s list of disinfectants that have been tested and are effective at killing the coronavirus includes products made with bleach, isopropyl alcohol, quaternary ammonium compounds (or “quats”) and others. Products containing these disinfectants remain difficult to find in retail stores and online.
The fact that there are few natural green cleaners on the EPA’s coronavirus-killing list “doesn’t mean that natural cleaning products won’t work; it just means they haven’t been tested,” says Bill Wuest, a chemistry professor at Emory University in Atlanta. He explains that the EPA only gives approval to a cleaning product if it follows its own protocol for being tested on a specific virus.
Wuest’s colleague Cassandra Quave, a medical ethnobotanist and an assistant professor at the Emory School of Medicine, says “studies are needed on the efficacy of natural products from plants against coronavirus.” So far, the EPA list includes some “safer” disinfectants, such as citric acid and alcohol, but this is far from exhaustive, and more green products need to be tested. She explains that a lot of the testing has been delayed because there aren’t enough labs with permission to safely work with live coronavirus.
Quave’s research team is now ramping up a study to ask questions about natural substances in cleaning products, such as essential oils from citrus and lavender. Some research has shown that limonene from citrus has antibacterial and antiviral properties, but it’s not known whether it’s effective specifically against the coronavirus. Until the EPA has added green cleaners to its list of products that can kill the coronavirus, she says to stick to approved, traditional disinfectants.
There’s no need to obsessively disinfect every household surface daily if you rarely leave your home and no one in your household has the coronavirus. Routine cleaning will do. And for that, you can use any product you prefer, whether it’s “natural” or not. It’s based on your preference.
Most people won’t have problems using products made with bleach (such as Clorox) or quats, as found in Lysol Disinfecting Wipes and Fantastik, if they follow label instructions. Other people are more sensitive and find that these products irritate their skin and eyes. Studies show that it is possible for these products to trigger symptoms in people who already have asthma or cause the onset of asthma in people with no prior history (more likely for bleach than for quats). However, this is more common with frequent occupational use of harsh disinfectants, not household use.
Though many green products are marketed with buzzwords such as “natural,” “plant-based” and “nontoxic” to appear better for human health, the truth is that any product can be harmful if used incorrectly.
Ultimately, there’s no one-size-fits-all cleaner that’s safe for everyone. Chemistry professor Joe Schwarcz, director of the Office for Science and Society at McGill University in Montreal, says “people are biochemically individual, and it is possible that some people will be irritated by even low concentrations of bleach, just as some people will be irritated by certain natural cleaners.”
Schwarcz says many natural products are “greenwashed” by companies that make “misleading claims about how a product is better for your health and safety, but without the evidence to back it up.” He frowns on the overuse of words such as “natural” or “plant-based,” which is not government-regulated.
“What’s bothersome is the insinuation that if something is natural, it’s inherently safer or is better than something that is synthetic,” Schwarcz says. “This is one of the biggest myths out there. The safety of any substance does not depend on its origin; it depends on what goes into the process of making it, and what you’re left with at the end.” Even if a green product starts with plant-based ingredients, those ingredients go through chemical processes to become functional cleaners.
Wuest agrees. “Natural cleaners can be corrosive, and regular cleaners can be safe. Lots of things that are made ‘naturally’ are just as toxic,” he says.
If you want to choose a natural cleaner without the greenwashed hype, pick a product from the EPA’s Safer Choice list. This is not to be confused with the list of coronavirus-killing disinfectants; this list is just for cleaners that have been tested by the EPA and pose the least concern among chemicals in their class. They have been tested for their effects on human health and may have a lower risk of causing asthma, irritation, hormonal disruption or carcinogenic effects. Remember: These are fine for routine cleaning, but they are not disinfectants for coronaviruses.
In addition to choosing a product from the EPA’s List N, you need to use it correctly. Although some disinfectants can be effective in killing coronaviruses in as little as 30 seconds, others must be left on surfaces for as long as 10 minutes. Read product labels to know for sure.
I was curious about how these researchers disinfect at home, so I asked each of them and got a variety of answers. Quave uses isopropyl (rubbing) alcohol, which is on the EPA’s list, but she adds a few drops of essential oil, such as lavender or lemon, for aromatherapy. “Alcohol-based products are probably the greenest that we can get that have been shown to be effective,” she says. “You need 70 percent alcohol for disinfecting; drinkable alcohols are not going to be high enough in alcohol to kill coronaviruses.”
Schwarcz cleans his countertops with dishwashing detergent, hydrogen peroxide spray or a diluted bleach solution. If you choose bleach, the Centers for Disease Control and Prevention recommends using four teaspoons of bleach per quart of water. But this mixture is potent only for about 24 hours, because bleach quickly breaks down in water.
Wuest thinks bleach is too strong; he prefers quats. “I would defer to milder disinfectants and cleaners, rather than going to the chain-saw version of a cleaner,” he said. “In my opinion, quats are the most effective and least harmful of the disinfectants on the market right now. I have two young children, and I have no concerns with any of the quats or wipes.” Wuest’s lab, which researches quats, has validated that their toxicity dose is fairly high, which means he’s not concerned that you would reach that level with regular home disinfecting.
The bottom line: You can use any green or traditional product for basic cleaning. But for disinfecting, especially if you are living with someone with or at risk of contracting the coronavirus, stick to items on the EPA’s List N, and choose rubbing alcohol if you want a more “natural” choice. Of course, if a certain product irritates your skin or causes respiratory symptoms, avoid it. As for the best disinfectant to use, you can see from my interviews with three scientists who all prefer different products that it’s really an individual choice.
Rosenbloom, a registered dietitian, is president of Words to Eat By and specializes in writing, nutrition education and recipe development. She is the co-author of “Nourish: Whole Food Recipes Featuring Seeds, Nuts and Beans.”