Experts have warned that the extra cleaning that people do by wiping surfaces and generally dispensing disinfectants all over the home are unlikely to limit the spread of COVID-19 — or any bacteria for that matter, but will increase people’s exposure to the chemicals used in those products — some of which may be hazardous to health.
Researchers worry that repeated inhalation or skin contact can be harmful over time.
Since the COVID-19 infection hit the world, cleaning protocols in schools, stores and other public spaces have increased, with a spray and a wipe-down becoming the order of the day every time we use a surface.
Fear of the coronavirus also prompted people to use more disinfectant wipes and sprays in their homes.
Scientists say that it is worth taking stock of as to whether the risks of using certain cleaning products are greater than the rewards.
Bleach can be damaging to skin and eyes if contact occurs. It has also been linked to asthma among professional cleaners as well as people who use it frequently in the home
Crucially, the experts said that simple soap and water are sufficient for regular cleaning.
Here’s what to know about the safety risks of the most common antimicrobial chemicals and how to reduce your exposure while keeping your home hygienic.
Which of my cleaning products are disinfectants?
Disinfectants are commonly found in all-purpose surface cleaners marketed for use in kitchens or bathrooms. Examples are Lysol sprays, Clorox wipes or anything else that says “kills 99.9% of germs” on the label.
The most prevalent disinfecting chemicals are quaternary ammonium compounds, also known as “quats” or QACs. Their chemical names typically end in a variation of “ammonium chloride,” such as alkyl dimethyl benzyl ammonium chloride or the snappier benzalkonium chloride.
The other main types of disinfecting chemicals are chlorine-based products — namely, bleach (sometimes labeled sodium hypochlorite); different types of acids, including citric acid, hydrochloric acid or lactic acid; and hydrogen peroxide.
Knowing what’s in a cleaning product can be tricky because some governments do not currently require companies to list chemicals on labels. And that’s why you should stick to what you know.
What are the concerns with these chemicals?
The health risks cleaning chemicals pose are hard to pin down because exposure is difficult to quantify, and many of the commonly attributed conditions — including asthma, cancer and infertility — take years to develop.
Some of the research that exists has been done in professional fields to determine whether certain health problems are more prevalent in people who have higher exposure levels, such as janitors and nurses.
Other studies conducted on mice aim to more directly test whether certain chemicals cause negative health outcomes, but findings in animals don’t always apply to humans.
According to the currently available research, the most concerning disinfecting chemicals are the ones used most often: quaternary ammonium compounds (QACs) and bleach.
In professional settings, QACs have been linked to skin irritation, asthma and other lung problems. For example, several studies found that nurses who frequently use the chemicals to disinfect surfaces and medical equipment had higher rates of asthma and chronic obstructive pulmonary disease, although other research did not find a significant association.
A 2021 study found that the presence of QACs in human blood was linked to disrupted immune and metabolic functions. In mice, exposure to QACs decreased fertility.
A series of recent papers found high levels of QACs in the dust in people’s homes, in blood samples and even in breast milk. Researchers measured levels of several different QACs common in cleaning products and compared the amounts present in 2019 and 2020. QACs were detected in a vast majority of samples, and in the dust and blood studies, the levels rose by an average of about 70% after the pandemic started. The more often people used disinfecting products in their homes, the higher their QAC levels were.
“When we started seeing them in each and every sample and at high levels, we were really surprised,” said Amina Salamova, an assistant professor of environmental health at Emory University, who led the research. “Exposure to QACs is widespread, which was the case before COVID as well, but it definitely has increased since the pandemic.”
There are also concerns that QACs could contribute to antibiotic resistance in bacteria. Partly for this reason, one QAC, benzethonium chloride, was banned by the Food and Drug Administration from being used in hand sanitizers, as was the disinfecting agent triclosan.
In light of this mounting evidence, several health and environmental groups have flagged quaternary ammonium compounds as chemicals of concern.
Bleach is a more familiar disinfectant to many people, but experts have raised concerns about its safety as well.
“It’s hard not to talk about it,” said Samara Geller, senior director of cleaning science at the Environmental Working Group. “It’s in every cleaning product, practically.” The chemicals in bleach “are persistent in the environment, and they’re also very corrosive,” she added.
Bleach’s corrosive nature means that it can be damaging to skin and eyes if contact occurs. It has also been shown in numerous studies to be linked to asthma, among professional cleaners as well as people who use it frequently in the home. Diana Ceballos, an assistant professor in the department of environmental and occupational health sciences at the University of Washington, said that one of the American Lung Association’s “recommendations on how to avoid asthma or prevent asthma or ameliorate asthma” was to avoid using bleach.
A risk unique to bleach is the potential for producing toxic gases — namely, chlorine gas, which has been used as a chemical weapon. The reaction occurs when bleach is mixed with ammonia — which is found in many glass cleaners, oven cleaners and some all-purpose cleaners — or acids, including vinegar.
So what should I be using to clean?
“We definitely recommend people substitute with some DIY recipes instead of buying products off the shelf,” Geller said. “Even a dash of dish soap with a bit of baking soda can help remove that scum off your sink or out of your bathtub, and that can really help you to avoid some of the heavier, harsher chemicals.”