Early this summer, news began to surface that several sunscreens contained several different chemicals linked to cancer, leaving people wondering what is safe to use—and what they should toss from their beach bag.
We asked Christopher Bunick, MD, PhD, a Yale Medicine dermatologist, to explain the situation.
Benzene in sunscreen: What you need to know
In late May, Valisure, an independent quality assurance company in New Haven, Conn., detected high levels of benzene, a known human carcinogen, in 78 sunscreen and after-sun care products. The Food and Drug Administration (FDA) regulates sunscreen as a drug product and after-sun products as a cosmetic.
Benzene is known to cause cancer in humans, according to the Centers for Disease Control and Prevention (CDC), the U.S. Department of Health and Human Services, the World Health Organization, and other regulatory agencies. It is a highly flammable chemical that is a natural part of crude oil, gasoline, and cigarette smoke and is used to make plastics, nylon, and synthetic products. It is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.
Long-term exposure to inhaled benzene can cause leukemia. What’s perhaps most troubling is that it is not an intended ingredient in any sunscreen product or production process, which leaves many wondering how it got in there and how they can protect themselves if there is no way to know how and when it was introduced.
According to Valisure’s report, 27% of the tested samples—which included aerosol sprays and lotions—contained detectable levels of benzene, and some contained up to three times the conditionally restricted FDA concentration limit of 2 parts per million. The company petitioned the FDA, asking for a recall of the contaminated products, and requested that the FDA better define limits for benzene contamination in drug and cosmetic products.
If you are concerned, my advice is to use mineral-based sunscreens, hats, and sun-protective clothing, and wait for the FDA to do their research. Christopher Bunick, MD, PhD, Yale Medicine dermatologist
It’s important to emphasize that the affected products were contaminated with benzene, something that could have happened to any product and not just sunscreen, says Dr. Bunick. “Since there was a batch-to-batch variability of the benzene levels in the products, that makes us think it’s a problem in the manufacturing process and the companies aren’t doing enough quality control,” he says.
The contaminated products came from a variety of companies, including Johnson & Johnson, which in late July, issued a voluntary recall of several sunscreens from its Aveeno and Neutrogena brands. “The fact that J&J recalled their products validates the findings. CVS and other brands quietly took some of theirs off the shelves, too,” Dr. Bunick says.
The FDA is reportedly evaluating Valisure’s petition.
In the meantime, consumers can make sure none of those recalled products are in their homes, but beyond that, it’s hard to give advice about how to handle this news since it’s still not clear how benzene got into the products.
“A safe level of benzene in sunscreen products doesn’t exist,” Dr. Bunick says. “One potential hypothesis of how the benzene was introduced is that it came from the ethanol used in the manufacturing process.”
Understanding the octocrylene and benzophenone connection
Another group recently came out with data about a different carcinogen in certain sunscreens, calling for the FDA to remove all sunscreens containing the active ingredient octocrylene from sale. About 2,400 sun-protection products contain the ingredient.
Products made with octocrylene can naturally degrade into the chemical benzophenone, a suspected carcinogen that can interfere with key hormones and reproductive organs, according to a study published in Chemical Research in Toxicology in March. The study was by French and American researchers from Sorbonne University and Haerecticus Environmental Laboratory, a Virginia-based nonprofit that studies health and environmental risks.
The researchers tested 16 octocrylene-based sunscreen sprays and lotions purchased in France and the U.S., and all of them tested positive for benzophenone.
“Benzophenone is a suspected carcinogen, and we know that this chemical reaction causing the degradation of octocrylene is occurring in sunscreen over time,” Dr. Bunick says. “It’s a chemical that doesn’t have to be there. We have a tendency in our society to say that it’s such a small amount and, therefore, it’s not harmful—but the chronic buildup of these chemicals could have a cumulative effect.”
The good news in this case, Dr. Bunick says, is that consumers have choices and there are sunscreen products available that don’t have this chemical in them.
“You don’t have to buy products with octocrylene, and hopefully, the companies and the FDA do the responsible thing and improve quality control checks on their products,” he says. “Personally, I don’t use sunscreen with that ingredient, and I do not recommend it to my patients. Is it possible that in the future, science shows us that it’s OK for octocrylene to be in sunscreen and that chronic use does not cause cancer in humans? Sure, but right now, we don’t know that.”
Furthermore, this provides an opportunity for innovation when it comes to skin care, Dr. Bunick says. “There is a recent grant call from the National Institutes of Health to look at chemical toxins and how they interact with the skin barrier, and we need to have further studies,” he says.
Haven't we heard about problems with chemical sunscreens before?
First, it helps to know that sunscreens are either mineral- or chemical-based. Some sunscreens contain both. Mineral sunscreens, which often contain zinc oxide and/or titanium dioxide, sit on the skin’s surface to deflect the sun’s rays. Chemical sunscreens, on the other hand, penetrate the skin and absorb the sun’s rays.
In recent years, studies have shown that many of the common chemical ingredients used in sunscreens are absorbed into the body’s bloodstream at concentration levels higher than the FDA’s safety threshold. One concern is that the chemicals can disrupt hormones in the body.
In 2019, the FDA proposed a rule requiring sunscreen manufacturers do additional testing of 12 common chemical ingredients to ensure their safety and effectiveness. Where those efforts now stand is unclear.
“These studies about chemical absorption into the bloodstream are concerning, and we need to go back and do additional tests and see what is going on. My understanding is that the COVID-19 pandemic knocked this additional testing off track,” Dr. Bunick says.
Despite these worries, Dr. Bunick says there is no need to panic. “There is a lot of controversy right now about the chemical sunscreens. Likely, many are very good with no benzene contamination or octocrylene as an ingredient,” he says. “But if you are concerned, my advice is to use mineral-based sunscreens, hats, and sun-protective clothing, and wait for the FDA to do their research.”