You’ve probably already seen a TikTok or worrying headline about it, but beauty conglomerate Unilever announced a voluntarily recall last month of several of its dry shampoos (from brands including Nexxus, Dove, Suave, TIGI—Rockaholic and Bed Head—and TRESemmé) due to elevated levels of benzene, a known human carcinogen. In a company release, Unilever stated, “Based on an independent health hazard evaluation, daily exposure to benzene in the recalled products at the levels detected in testing would not be expected to cause adverse health consequences.” The recall was declared “out of an abundance of caution,” with no reports of adverse events to date.
Still, if you’re one of the many people who uses dry shampoo (maybe more often than you use regular shampoo), the recall may have left you wondering about your personal risk. After all, we know that long-term exposure to high levels of benzene can lead to cancers such as leukemia, according to the Centers for Disease Control and Prevention.
But are a few sprays of dry shampoo really that bad? Well, the answer is a little more complicated than a simple yes or no. After all, benzene is widely used in the United States. It ranks in the top 20 chemicals for production volume. In addition to its use in glues, paints, furniture wax, and detergents, it gets spewed into the atmosphere via volcanoes and forest fires. It is also a natural part of crude oil, gasoline, and cigarette smoke. In other words, you’re probably already subject to a fair amount of benzene exposure; how bad is a little more?
Why Is Benzene Even in Dry Shampoo?
Benzene isn’t supposed to be in dry shampoo. You don’t need it to make dry shampoo. Rather, it’s a chemical that may find its way into the can, because, at a molecular level, it tends to adhere to butane—a common propellant used in aerosols.
As Chris Cappa, a professor of environmental engineering at UC Davis in California, explains, “Butane is often produced from refining of crude oil. However, benzene is also in crude oil. Ideally, the different components are completely separated during the refining process, but sometimes we end up with some residual, unwanted components. In the case of these dry shampoos, there was a bit of unwanted benzene that came along with the butane.”
Other aerosol products have been recalled in the past because of the presence of benzene, according to the nonprofit Environmental Working Group. That list includes some Old Spice and Secret deodorant sprays and some Pantene and Herbal Essences hair products, as well as a few sunscreens. (A recent study in California also found that benzene commonly leaks from gas stoves.) .)
The problem, and why benzene is particularly troubling in dry shampoos, is that you spray them at your face and, generally, in enclosed environments like a bathroom. “You would be exposed to higher levels of benzene if you were two feet away from cigarette smoke than 10 feet,” Chris Reddy, a senior scientist at the Woods Hole Oceanographic Institution in Massachusetts, says. “And then, there’s the overlooked factor: length of exposure. Returning to cigarette smoke, it’s much worse if you are two feet away from a smoker for several hours locked in a room than if you are standing 10 feet away from a smoker outdoors.”
Does that mean there’s a safe way to use dry shampoos in aerosol form? The jury is still out. When asked if he’d use aerosols, cosmetic chemist Ron Robinson at BeautyStat says, “I use an antiperspirant deodorant spray that contains butane every day, and I’m not concerned.” Others are not so sure. “I try to eliminate potential carcinogens,” Cappa says. “If I were to use them, I’d use them outside where they can be diluted. But all of these things are a choice.”
What Are the Alternatives to Aerosol Dry Shampoos?
Let’s say you’re choosing to eliminate potential carcinogens from your beauty regimen. The good news is, you’ve got options. The not-so-good news is that they can come with compromise.
When she was researching how to formulate her company’s dry shampoo, Mary Futher, a.k.a. “Madame Sweat,” founder of Kaia Naturals, quickly discovered that there were shockingly few ways to shoot powder out of a can (a crude explanation of how aerosol dry shampoos work). “There’s either a propellant or a bag and valve in the can. But the bag-and-valve method produces a wet spray, and you can’t have that for dry shampoo,” she says.
Her solution was to use a new “wing-lift” technology, which contains no propellants and instead relies on two levers inside the package to push powder up from the bottom of the bottle. “You shake it, then when you press down on the nozzle, the wings help disseminate the powder,” Futher says.
Kaia Naturals Dry Shampoo, Rahua Voluminous Dry Shampoo, and Better Not Younger Fresh Start Scalp Renewing Dry Shampoo all boast powder formulas, which you basically shake out of the container. Though they may not be as aesthetically pleasing as that fine, steady stream of dry shampoo that mists out of an aerosol can, Futher says these types of formulas contain a higher percentage of “bulk” (industry speak for the active product) relative to the propellant. This means that, at very least, they’re more economical.
Debra Lin, a Cornell- and MIT-educated scientist and engineer, and Better Not Younger’s head of product and innovation, adds that she dusts on the company’s dry shampoo with a kabuki brush for precise and even placement akin to that of an aerosol.
Perhaps the most promising innovation in aerosol technology comes from Honeywell. The company has developed Honeywell Solstice® propellant, an environmentally friendly, low-global-warming-potential, non-ozone-depleting, volatile organic compound (VOC)-exempt propellant that can be used for personal care applications like hairspray and dry shampoo.
According to Joanna Minion, general manager of Personal Care/Aerosols at Honeywell, “Not only does it comply with regulations from the United States Environmental Protection Agency on reducing global warming potential, but it also helps formulators meet regulations from the California Air Resources Board on lowering the VOC content of haircare products.” Oh, and it also allows for a consistent, fine, dry spray from the start to the finish of the can. (Currently, you can find the technology in three of Fekkai’s newest products: Volume Lock Hair Spray, Flexible Hold Hair Spray, and Sheer Dry Shampoo.) Honeywell is working on applications of the new propellant for use in everything from personal and home care products to air conditioning in cars and trucks.
The Bottom Line on Dry Shampoos
“To be clear, no one intentionally puts benzene in their products,” Lin says. “The good thing is companies are actively testing their products.” We may not know where the defect occurred in the latest recall. The fact is, not every aerosol-powered dry shampoo contains benzene.
That said, there’s a case to be made for staying away from aerosol products as much as possible, Albert Rizzo, M.D., chief medical officer of the American Lung Association, says. “Individuals don’t realize that benzene exposure can vary a lot in homes—if there’s a connected garage or gas stored in containers for the lawn mower. So if there’s already a marked elevation in your home, using an aerosol product can just multiply your risk.” And that’s only intensified if you smoke or live with someone who does, as “half the amount of benzene we’re exposed to is through secondhand smoke,” Rizzo says.
If you think you may be entitled to a refund for your recalled dry shampoo from Unilever, click here.
