The most dreaded time of year rolls around every winter like clockwork: cold and flu season. The time when hand washing increases, sanitizing surfaces intensifies, and old and young schedule regular seasonal vaccines in an attempt to prevent sickness from descending on their households. But there’s one piece of ammunition you should absolutely skip this season—and all year-round—because it does more harm than good: antibacterial hand soap.
While hand washing is vitally important to curb the spread of disease, soap advertised as antibacterial not only doesn’t protect you better from disease, it has far-reaching and possibly harmful effects on your health and the environment. Here’s why to ditch it and use plain soap instead.
How does soap even work?
Regular soap can come in many forms: foaming liquid, bars, and gels. It is little more than a combination of fat or oil, alkaline substances (lye), and water. When you wash your hands with it, it loosens the bond microbes (of which viruses and bacteria are a subset) have made with your skin, which allows water to easily wash them away down the drain.
Antibacterial soap has a similar formula, but with the addition of one or more of three biocide chemicals: benzalkonium chloride, benzethonium chloride, and chloroxylenol. These were not part of the list of 19 antiseptics the FDA banned in consumer wash products in 2016, but they have been flagged as potentially dangerous. The FDA cited the importance of further study to “fill safety and efficacy data gaps,” but rule-making has been deferred for the last nine years.
These antimicrobial chemicals kill microbes instead of simply scrubbing them away. But they don’t differentiate between good and bad bacteria; they kill whatever is most susceptible.
However, “you don’t need to kill the bacteria, you just need to remove the bacteria,” says Rebecca Fuoco, director of science communications at the Green Science Policy Institute.
Antibacterial soap can also disrupt helpful bacteria on your skin that support healthy pH, barrier function, and pathogen defense, she explains. Chemical residues can also linger on skin, extending the disruptive biocide effect beyond the act of washing.
With plain soap, the surviving microbes and new arrivals from the environment can quickly recolonize, which helps keep the skin microbiome healthy, Fuoco states.
Bacteria aren’t always the enemy
Some of those good bacteria also prevent colonization of bad. Only a small fraction cause disease; most are biologically important for digestion, immunity and healthy ecosystems. Many help keep gut and skin microbiomes functioning properly, which helps prevent infections naturally.
“When that balance is repeatedly disrupted by killing off large portions of these microbial communities, their protective functions can break down and leave us more vulnerable to infection,” Fuoco says.
That’s a problem for internal biological systems, but also industrial ones. Many bacteria are used in wastewater treatment systems nationwide to help convert ammonia into nitrogen. When overuse of antibacterial soap runs down drains in large quantities, it has the potential to shut down entire plants.
In San Luis Obispo, California, this likely happened in September of 2020 when the vital process of nitrification—which occurs when bacteria convert toxic ammonia into nitrate, a form of nitrogen readily usable by plants—came to a screeching halt. It only recovered after treatment with expensive anti-antibacterial agents.
After plenty of tests, the most likely culprit became clear: college students returning to school and overloading the wastewater system with quaternary ammonium compounds (QACs), a class of chemicals used in disinfectants, soaps, wipes and sprays.
The harmful health impacts of antibacterial products
Scientists are just starting to understand the extent to which these products are linked to human disease, but the downsides are pervasive, and not just when people are first exposed. When soaps, wipes and sprays get washed down the drain, the QACs enter waste treatment systems.
“Because QACs are not fully removed by wastewater treatment and tend to concentrate in sludge that is applied to land, they can enter rivers and other waters that recharge groundwater or supply drinking water and recycled water systems,” Fuoco describes. QACs were recently detected in New York state drinking water.
“We’re using it so much that it’s coming back to us,” Fuoco says. In fact, researchers measured QACs in people’s blood before and during the COVID-19 pandemic, and in a paper published in 2021, levels increased by 77 percent, indicating bioaccumulation is significant.
People also absorb QACs through skin contact, inhaling aerosol from sprays or inadvertently ingesting contaminated house dust. Children may be especially susceptible thanks to their close contact with floors and treated surfaces and hand-to-mouth behaviors, Fuoco notes. The American Academy of Pediatrics warns against using antimicrobial products around children.
Studies show correlations between antibacterial products and asthma and COPD in healthcare workers who are frequently exposed to these products in their workplace. Many types of contact can lead to ulcerative skin lesions and contact dermatitis in humans, and rodent studies have linked it to reduced fertility and neurodevelopment, even colitis-associated colon cancer in mice.
Overuse of antibacterial products can also accelerate antimicrobial resistance, leading to superbugs that are immune to the biocides and critical lifesaving antibiotics, Fuoco warns. Antimicrobial resistance is already a global crisis, with resistant infections spreading faster than the development of new antibiotics.
“We don’t know how much of this crisis is driven by antibiotic versus biocide overuse. The contribution of biocides like QACs has largely been overlooked by global authorities, but we [scientists who study these chemicals] are hoping that will change soon,” Fuoco says. The World Health Organization believes antibiotic-resistant disease could cause 10 million deaths each year by 2050 if nothing is done to curb use; currently, there are about 700,000 per year.
Overuse of antibiotics in animal agriculture has long been identified as a driver of the global antimicrobial resistance crisis, Fuoco says, but there is growing evidence that antibacterial product use is contributing, too.
Bad for the environment
When products containing QACs are washed down the drain, the chemicals are often released into aquatic environments. Since they are toxic to some fish and many invertebrates, the backbone of the aquatic food web, ecosystem balances can be thrown out of whack.
QACs also accumulate in the soil and on sludge from wastewater treatment plants that is often spread on agricultural products as fertilizer. These chemicals, like PFAS, are persistent, meaning they can be found in soil and other environments years after they are no longer in use.
Antibacterial soaps are not more effective
Independent studies show (and the FDA agrees) that there’s no meaningful health benefit to choosing antibacterial hand soap over plain soap and water when it comes to eliminating microbes on hands and preventing illness. That includes E.coli, viruses, and the “bad” bacteria.There is little evidence that disinfecting wipes, sprays, and laundry sanitizer in homes provides added health benefits beyond regular cleaning and proper laundering, either, Fuoco says.
Additionally, most antibacterial products have to be left wet on surfaces—including hands—for several minutes in order to be as effective as they claim. Most consumers don’t follow those instructions, so products aren’t nearly as effective as they may think.
What to look out for
According to Fuoco and many other scientists, the best and safest choice is to avoid antibacterial and antimicrobial products altogether, particularly those containing QACs or chloroxylenol. Hand washes marketed as antibacterial must list their active antiseptic ingredients. So on labels, look for terms like “antibacterial” or “antiseptic” and check ingredient labels for the ingredients benzalkonium chloride, benzethonium chloride, and chloroxylenol.
When wiping down surfaces in your home or office, opt for plain soap and water instead of disinfectant wipes and sprays. “It’s usually unnecessary to disinfect surfaces in your household,” Fuoco states. The exception is when there’s been blood, fecal matter, or vomit from a sick person on surfaces. Other options like diluted bleach, hydrogen peroxide, alcohol-based products, or citric-acid-based disinfectants can do the job while generally posing fewer health and environmental concerns, she continues.
So, ditch the antibacterial products altogether and fight cold and flu season the old-fashioned way: with plain soap and water. You’ll fare just as well and leave your long-term health and that of the environment better for it.
