Last week the U.S. Food and Drug Administration (FDA) announced a nationwide dry shampoo recall due to “elevated levels of benzene” in dozens of aerosol products. Recalled items included Dove, Nexxus, Suave, Rockaholic, Bed Head, and Tresemmé dry shampoo canisters produced before October 2021.
This isn't the first time benzene contamination prompted a cosmetics recall in recent history. In December 2021, Procter & Gamble recalled aerosol dry shampoo and conditioner spray products from Pantene, Aussie, and Herbal Essences due to detected benzene.
To help shed some light on the dry shampoo recall and potential risks of the chemical involved, we asked toxicology experts all about benzene and what this means for consumers moving forward.
What is benzene?
According to Christopher M. Reddy, PhD, a senior scientist at Woods Hole Oceonographic Institution specializing in chemistry and geochemistry, benzene is an organic chemical that is found naturally in crude oil and other fossil fuel products, such as coal.
“You don’t need a laboratory to ‘make’ benzene, and it's not related to human activities,” he says, pointing to volcanoes and forest fires as examples of natural occurrences that cause benzene to form. “Crude oil can seep into the environment naturally, [like the] La Brea tar pits, or how the Clampetts got rich in the TV show Beverly Hillbillies.’”
Human beings can still be responsible for the formation of benzene however: Cigarette smoke and gasoline both contain the chemical, meaning oil spills can contribute to benzene contamination—especially if near a water supply. Benzene is also produced at factories and oil refineries, as it's a relatively simple compound, he says. “Due to benzene’s simplicity and willingness to react with other chemicals, it is more often made at factories as a ‘precursor’ to make a bigger chemicals,” Reddy says. “Think of it as a single Lego when you building a small structure composed of 10 pieces.”
Is benzene dangerous?
Benzene is a chemical carcinogen. However, context is key: People breathe in low levels of the compound every day. “Products like cigarettes, gasoline, glues, paints, and certain plastics contain benzene,” Reid Maclellan, MD, director of Proactive Dermatology Group and founder and CEO of artificial intelligence health care company Cortina, tells Glamour. And it's true: From car emissions to gasoline while filling your lawnmower, there are countless opportunities to expose oneself to benzene on a day-to-day basis. Even Banana smoothies have been found to be contaminated with it, adds Hans Plugge, a principal who specializes in toxicology at Safer Chemical Analytics LLC.
Relatively consistent exposure does not mean benzene is risk-free, however. According to Dr. Maclellan, short-term symptoms to high benzene exposure can include dizziness, confusion, drowsiness, vomiting, stomach irritation, or headache, and long-term effects could lead to cancer, anemia, and low blood cell counts as benzene kills white blood cells. He also says that if you have experienced any symptoms stated above, to seek medical attention. However, Plugge clarifies that it's benzene only in high concentrations that is known to be carcinogenic and cause anemia.
“The level of exposure determines the risk,” he says. “The levels in the product described in these studies are very low and exposure is even lower.”
Is the amount of benzene in the dry shampoo canisters cause for concern?
As noted above, benzene's effects on human beings are determined by the length and frequency you are in contact with the chemical. “While levels of exposure and people’s reactions to [benzene] are taken on a case-to-case basis,” Dr. Maclellan says, “based on what has currently been reported, it does not appear that the amount of benzene found in the recalled dry shampoo would have long-term health effects on those who used the products unknowingly.” Plugge agrees: “You are exposed to much higher benzene levels pumping your own gas,” he says.
However one can see why consumers would be worried about aerosol cans in particular. “You are literally spraying near your nose, mouth, and ears in generally an enclosed space, the bathroom,” Reddy notes—though how much you potentially inhale depends on varying factors such as whether the bathroom fan is running, how much dry shampoo was sprayed, and how long one stays in the bathroom after using it.
“Benzene in daily life is a constant exposure for nearly everybody at an extremely low level except for possible occupational exposures,” adds Plugge. “While it may be theoretically possible to avoid all benzene exposures, it is not doable in everyday life. Natural products contain benzene, like the banana smoothie, gasoline contains benzene, propellants contain benzene. At the levels cited, the latter is the least of anybody's concern.”
How and why did benzene end up in the dry shampoo?
The source of the contamination remains unclear. “The spray cans’ propellant has been identified as the source of benzene in the dry shampoo, and they are working with the manufacturer to get to the bottom of this,” Dr. Maclellan says, though he clarifies that companies are not putting benzene into their products on purpose, since the harmful effects of these chemicals are universally recognized.
“Benzene is a very, very well-known chemical,” Reddy says, “and it's not hard to measure, either, if you have the correct equipment. Chemists have developed advanced chemical techniques to measure benzene very accurately and at low levels.” Translation? What likely happened is the cans had not yet been measured for benzene levels when they left the factory, a fraction of canisters somehow slipped through quality control, and/or some chemical in the cans may have broken down inside the can after they left the factory. “If benzene is a product of a reaction that occurred inside the can, the factory may have missed benzene because it was not there,” Reddy says.
How can I safely use dry shampoo until this gets figured out?
If you are concerned about dry shampoo and/or benzene exposure in products overall, Dr. Maclellan suggests finding alternatives to aerosol products. “Dry shampoo, sunscreen, hairspray, and setting spray all have alternatively packed powder or liquid forms as opposed to spray options that can be used,” he says. “This is an effective way to avoid possible contaminations while this recall is being figured out.”
Shop some of our favorite nonaerosol dry shampoo products below.
Danielle Sinay is the associate beauty editor at Glamour. Follow her on Instagram @daniellesinay.
