(Bloomberg) -- Just before the British government announced a nationwide lockdown, Lucy Dargahi found herself browsing the shelves of her local corner shop in West London. Like many of her fellow shoppers, she was thinking about cleaning.

The 28-year-old usually buys plant-based household cleaners from Method Products Inc. But with the novel coranavirus spreading around London, she picked up a bottle of Advanced Power Kitchen with “power foam” from Mr. Muscle, a brand owned by Windex-maker SC Johnson Inc. and sold in the U.K. since 1974. The product promises to kill 99.99% of viruses and bacteria. Its strongest ecological credential is encouraging shoppers to buy refills.

“It was almost like survival mode, where I just thought, ‘I need whatever protects me and my family,’” Dargahi says. “Before this, protecting the planet was my No. 1 concern when I was shopping. But when it comes to health risks, there’s no compromise.”

Eco-consumerism has grown in recent years as people have become more aware of the social and environmental impact of the products they buy. In 2017, the year after Unilever NV agreed to purchase natural cleaning brand Seventh Generation, the consumer giant found that a third of shoppers globally prefer sustainable brands. Since then, public concern about the environment has soared.

But recent data from market researchers at Nielsen shows that people are turning away from natural cleaning products in their bid to fight the spread of Covid-19. “The balance is shifting as people realize this is really, really, really bad, and that’s when they’re going for the efficacy over natural,” says Philipp Lohan, a global business partner at Nielsen.Consumers around the globe have largely followed the same spending patterns as the pandemic progresses. In the earlier stages of the crisis, according to Nielsen’s research, overall demand rises for health and wellness products, including natural options. As governments start to take emergency measures, however, panic buying sets in and synthetic chemical disinfectants begin to dominate consumers’ choices.

In Italy, which has been under lockdown since early March, people are choosing petrochemical-based disinfectants over plant-based products, Nielsen’s data show. In the U.S., which didn’t adopt widespread lockdowns until much later, sales of plant-based household cleaners have spiked 241%, compared to 121% for petrochemical options. The U.K., where lockdowns came later than in Italy, has recorded equal exponential growth in both eco and non-eco brands.

These decisions may be based on a fallacy, says Tom Welton, a professor of sustainable chemistry at Imperial College London. Or rather two fallacies: that synthetic chemical products are necessarily better at cleaning, and that natural products are necessarily better for the environment.

“Hot soapy water is a fantastic cleaner of hard surfaces,” he says. “You could even use shower gel.”

Soap is a surfactant, which means it lifts dirt and oil off of surfaces; it also dissolves the oily skin of the coronavirus, effectively destroying it. On hands and dishes, a surfactant is all you need. On other hard surfaces such as tabletops and electronic devices, where a thorough rinse is more difficult, a disinfectant such as bleach or even a 70% alcohol solution will do a better job.

When used appropriately, a plant-derived soap can be just as effective as chemicals made in a lab. Welton says he has been using a mixture of soapy water and bleach to keep his home virus-free.

Assessing the environmental footprint of a cleaning product is more complicated. Consumers tend to focus on the origins of ingredients, but packaging materials, manufacturing practices and transportation factors can all make a “natural” cleaning product carry a greater environmental cost than a synthetic alternative.What matters most is how we use a product, Welton says, not what’s in it. “We use far, far too much” detergent compared to what we actually need much of the time, he says. Buying single-use tablets or packets, often seen as wasteful by eco-conscious consumers, can help with portion control. While chlorine bleach is more environmentally damaging than average dish soap, peroxide-based bleach is a greener alternative.

As with everything related to the coronavirus, scientists and analysts say it’s hard to predict what will happen to the eco-cleaning market as the threat recedes. Dargahi, for one, says she’ll return to using Method once the crisis has passed. History suggests others may not.

In the mid 2000s, steady growth in organic food sales were stopped cold with the economic crash in 2008. This time around, eco-consumerism is more mainstream. Yet in a recession, shoppers may not choose to pay a big premium on laundry soap that’s marketed as “earth friendly” while worrying about job security.

“If your primary concern is the money in your pocket then you’re going to make more discerning choices about what you buy,” says Matt Bowman, a strategic insight director at market researchers Kantar. “It’s likely that if we do see a bit more of a crash, people’s immediate concerns will change.”

©2020 Bloomberg L.P.