Carcinogenic Benzene Is Found in Acne and Rosacea Products

Benzoyl peroxide (BPO) was first created in 1858. By the 1920s, doctors were using it as both a local antiseptic and a local anesthetic to treat burn patients and those with skin ulcers. By the 1950s BPO was being recommended for rosacea. One of the giants in dermatology, Dr. Albert Kligman, wrote that benzoyl peroxide was being used in the US for the treatment of acne by 1960. Tens of millions of teenagers and adults have used topical products containing BPO for decades. Now we learn of a potentially serious problem. One of the most prestigious dermatology journals in the world, The Journal of Investigative Dermatology, Oct. 2024, has just published a bombshell article. In it we are told that benzene is found in an alarming number of acne and rosacea products.

What’s Wrong with Benzene in Benzoyl Peroxide?

The article in the Journal of Investigative Dermatology (October, 2024) begins with this sentence:

“The potent carcinogen, benzene, is a known degradation product of benzoyl peroxide (BPO) and was recently reported to form when BPO drug products, used for acne and rosacea treatment, are incubated at body temperature and elevated temperatures expected during storage and transportation.”

The authors go on to state:

“Many products are applied once or twice daily and treatment duration ranges from months, for mild to moderate acne, to years for severe acne suggesting that exposure to benzene through BPO drug products should be considered chronic and, therefore, of greater risk to cumulative carcinogen exposure.”

The study reports that 34% of the tested products had unacceptable levels of benzene. The researchers go on to state:

“There is no safe level of benzene exposure to humans and FDA guidance specifies that drug products should not contain benzene because of its unacceptable toxicity…A 1939 study on benzene stated that ‘exposure over a long period of time to any concentration of benzene greater than zero is not safe,’ and the hematotoxicity of benzene has been described as early as 1897. The first industry review of benzene was conducted by the American Petroleum Institute in 1948 and concluded that ‘it is generally considered that the only absolutely safe concentration for benzene is zero.’ A 2010 review of benzene research specifically stated, ‘There is probably no safe level of exposure to benzene, and all exposures constitute some risk in a linear, if not supralinear, and additive fashion.’”

The FDA and Benzene:

The Food and Drug Administration has a page titled:

“Frequently Asked Questions on Benzene Contamination in Drugs“

Here are just a few of the Q&As when benzene is found in pharmaceutical products:

“Q: What should consumers know about drugs being recalled for benzene contamination?

A: Certain hand sanitizers and aerosol (spray) drugs, including antiperspirants and sunscreens, have been recalled due to benzene contamination.

Consumers should stop using products that have been recalled as well as those hand sanitizers FDA recommends consumers should not use, including hand sanitizers tested by FDA and found to contain unacceptable levels of benzene.”

“Q: What is the risk from using drugs contaminated with benzene?

A: The health consequences of benzene exposure depend on the amount, route, and length of time of exposure, as well as age and preexisting medical conditions. FDA recommends consumers do not use certain hand sanitizer products, or those that have been recalled.

In small amounts over long periods of time, benzene can decrease the formation of blood cells. Long term exposure to benzene through inhalation, oral intake, and skin absorption may result in cancers such as leukemia and other blood disorders.

FDA continues to monitor the quality of drugs and, when appropriate, encourages retailers to remove products from store shelves and online marketplaces when issues arise.”

The agency goes on to state:

“FDA has been working with companies to address benzene issues in drugs prior to March 2021, including through recalls.”

How much prior to 2021 is not exactly clear. We doubt that it has been for decades.

What’s the Big Deal About Benzene?

Benzene is a carcinogen…full stop! According to the American Cancer Society:

“Benzene is known to cause cancer, based on evidence from studies in both people and lab animals. The link between benzene and cancer has largely focused on leukemia and other cancers of blood cells.”

The International Agency for Research on Cancer (IARC) links benzene to multiple myeloma, non-Hodgkin’s lymphoma and a number of leukemias. The United States National Toxicology Program (NTP) and the Environmental Protection Agency (EPA) consider benzene a “known human carcinogen.”

Acne Products Containing Benzoyl Peroxide:

There are lots of OTC and prescription acne products that contain benzoyl peroxide (BPO). This compound is found in creams, gels, cleansers and a variety of other formulations. It is left on the skin. People use BPO products for months or years. When it is on the skin of the face it is entirely conceivable that some benzene is liberated gradually over long periods of time. Does that mean people could be breathing in small amounts of benzene for years or decades?

Is Valisure the Dragon Slayer?

Valisure is an independent testing laboratory in New Haven, Connecticut. Over the last several years it has been a thorn in the FDA’s side. That’s because this lab has discovered carcinogens in a wide range of products: valsartan blood pressure pills • ranitidine (Zantac) heartburn meds • some metformin diabetes drugs • a bunch of hand sanitizers • too many sunscreens • a bunch of deodorants and antiperspirants • and a lot of dry hair conditioners and shampoos. Some of those products contained unexpected nitrosamines. Others had benzene. That benzene is found in benzoyl peroxide is just the latest Valisure discovery (Journal of Investigative Dermatology (October, 2024).

They reported earlier:

“This study raises substantial concerns about the safety of BPO products currently on the market, which appear to form benzene, a known human carcinogen and environmental hazard. Benzene was detected in all BPO product samples tested and levels increased during incubation at body and shelf-life performance temperatures to >2ppm [parts per million], which is the conditionally restricted FDA limit for benzene for drug products. Furthermore, BPO was detected in the environment surrounding two unopened primary product containers, which suggests that BPO products could emit substantial amounts of benzene from their original packaging prior to use.”

An article in Dermatology Times, March 11, 2024, quotes Christopher Bunick, MD, PhD, FAAD, associate professor of dermatology and physician-scientist at the Yale School of Medicine:

“’So, what does this all mean and what am I going to advise for patients? I will say we as a community have to see what is validated. I do not necessarily think at this moment that no one should use benzoyl peroxide. I think there has to be a proportional response until more data comes out,’ said Bunick.

“He concluded, ‘With Valisure’s agreement, that for those providers and patients who wish to continue benzoyl peroxide-containing products, that a proportional response at this time would be to keep the product refrigerated at all times, renew the medicine every 3 to 6 months, and avoid heated storage. This will not necessarily eliminate all benzene, but should slow its decomposition. This measure gives the medical community a chance to await further investigation and recommendations.’”

Dr. Bunick has pointed out that:

“…every time Valisure detected a carcinogen in consumer products, some form of a recall followed.”

Speaking of Recalls and Valisure Research:

On December 17, 2021 Procter and Gamble (P&G) announced a recall of hair care products contaminated with benzene. It involved aerosol hair products including dry shampoo or conditioners under brands such as Aussie, Herbal Essences, Old Spice and Pantene. You might think other manufacturers of such products would have paid close attention. But the testing laboratory Valisure announced on November 1, 2022 that it found benzene in 70% of the 148 batches of dry shampoo products it tested.

What Is Dry Shampoo?

When I think of shampoo, I imagine some sort of viscous liquid or gel that goes on in the shower. It foams and cleans your hair and then gets rinsed out.

Dry shampoo, on the other hand, can be applied anywhere. And yes, it is sprayed on while your hair is dry, not wet! It is not rinsed out. Such products often contain alcohol and/or starch that absorb oil or sweat.

Women often apply dry shampoo to maintain the look of a “blowout.” The bottom line seems to be that dry shampoo and conditioner help the hair look less greasy and serve as a quick fix after exercise. It won’t, however, clean the hair or scalp.

Where Have They Found Benzene?

You can find a list of hair products that contained benzene in Valisure’s FDA Citizen Petition on Drug Shampoo. Some of the products that were listed included Not Your Mother’s Clean Freak Refreshing Dry Shampoo, Paul Mitchell Invisiblewear Brunette Dry Shampoo, Batiste Dry Shampoo Bare and Redken Deep Clean Dry Shampoo.

Valisure pointed out that:

“Dry shampoo products are considered cosmetics that are regulated by the U.S. Food and Drug Administration (‘FDA’). Valisure has tested and detected high levels of benzene in specific batches of certain dry shampoo products.”

When P&G Found Benzene in its Dry Shampoo and Conditioners:

Procter & Gamble voluntarily recalled aerosol dry conditioner spray products and aerosol dry shampoo spray products when it realized benzene was a problem.

It went on to describe why it took this action:

“Risk Statement: Benzene is classified as a human carcinogen. Exposure to benzene can occur by inhalation, orally, and through the skin and it can result in cancers including leukemia and blood cancer of the bone marrow and blood disorders which can be life-threatening.”

Valisure points out that:

In a nutshell, you would do better not to expose your body to benzene.

Where Else Have They Found Benzene?

These product recalls follow on the heels of earlier benzene-related recalls from many companies. Products pulled included hand sanitizers, spray-on sunscreens, aerosol antiperspirants and deodorants and athlete’s foot sprays.

Carcinogens have also been found in oral medications. By the way, on October 9, 2024 it was announced that GSK will settle over 80,000 Zantac lawsuits by paying up to $2.2 billion. These were cases brought by patients who believed that their heartburn drug (also known as ranitidine) had caused their cancers.

Valisure adds:

“There is a recent history of broad drug and consumer product recalls due to contamination with probable human carcinogens. Specifically, there have been a multitude of manufacturer recalls of medications, such as valsartan, irbesartan, losartan, ranitidine, nizatidine, and metformin, due to the detection of the Group 2, ‘probable human carcinogen’ N-Nitrosodimethylamine (“NDMA”) in excess of FDA limits.”

Ask most people what disease they fear most and it will likely be cancer. We do not need extra carcinogens in our pills or our cosmetic products.

Why Worry If a Little Benzene Is Found?

Drug manufacturers and cosmetic companies often downplay the risks of carcinogens in their products.

I always love it when a manufacturer of body care products adds this message:

“To date, The Procter & Gamble Company has not received any reports of adverse events related to this recall and is conducting this recall out of an abundance of caution.”

We have read similar messages from the makers of acid-suppressing drugs and blood pressure medications that contained nitrosamines. The problem with this kind of don’t-worry clause is that cancer does not happen overnight.

It takes years or even decades of exposure to cause malignancy. Proving that benzene exposure led to someone’s cancer is incredibly difficult. It hardly surprises us that big companies can say they have not received any reports of adverse events.

An In-Depth Overview in Chemical & Engineering News:

Craig Bettenhausen, a writer for Chemical & Engineering News (c&en), contacted me for an article he was writing about benzene. Here is a link to

“Finding Benzene Everywhere We Look:
Questions pile up as scientists find the carcinogen in more and more consumer products”

This in-depth report was published in c&en (Dec. 20, 2021).

If Benzene is Found, Where Is It Coming From?

There is quite a discussion about how the benzene gets into all these different products. Scientists aren’t sure where the found benzene is coming from. One hypothesis is that the propellants in aerosol products may be contributing. That’s because they often come from petroleum-based products such as propane or butane.

There is also controversy about the levels of benzene that have been discovered. Even if they found benzene as a contaminant, is it worrisome?

One of the messages from Valisure in its Citizen Petition to the FDA involves exposure. It’s not just the direct application to the skin or scalp that concerns us. When people use an aerosol spray product to apply an antiperspirant or hair product, they are often in a bathroom. That is a small contained space. They are likely inhaling some of the aerosolized particles. That could increase benzene exposure.

Craig Bettenhausen quoted me in our interview:

“The bottom line is, most people would prefer to avoid carcinogens, even in low doses, over long periods of time.”

Where’s the FDA?

Not all companies have been as proactive as P&G in removing contaminated products. The FDA has been slow to detect benzene in consumer products and even slower to take action. That leaves a lot of people wondering which of their acne or aerosol personal care products are safe.

Shouldn’t the Food and Drug Administration be more proactive?  FDA scientists have not discovered most of the benzene that has been found. Why not?

We will put in a shameless product promotion for our own deodorants. As soon as we learned that some antiperspirants and deodorants contained benzene, we shipped our MoM (Milk of Magnesia and now Magnesium Rich) aluminum-free roll-on deodorants off to Valisure for testing.

We were relieved to learn that they found no benzene! So, our deodorants contain neither aluminum nor benzene. You can find them at this link. And if you would like to learn more about benzene in deodorants and antiperspirants, here is a link:

Are You Breathing Benzene or Putting It In Your Armpits?

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