"Here, it is not contamination, rather benzoyl peroxide breaks down into benzene, stimulated to do so by the formulation of the products themselves. What is concerning is that nearly all benzoyl peroxide-containing products tested formed benzene (even the new triple combination topical), often at levels 2 to 1000x higher than the emergency/conditional FDA limit of 2 ppm," he said. "To make matters worse, benzoyl peroxide breakdown into benzene was accelerated by exposure to elevated temperatures equivalent to a hot bathroom or car, meaning that patients and consumers must be mindful of how to store their benzoyl peroxide-containing product (not in a car!). Even more concerning, as benzoyl peroxide breaks down into benzene, the gaseous form of benzene was found to penetrate through sealed packaging at levels nearly 1000x higher than EPA lifetime exposure limit (0.4 ppb) for the increased risk of 1 cancer per 100,000 people. Thus, benzoyl proxide-containing acne products unsuspectedly are also an inhalation risk."
Giving perspective for dermatologists and patients, Bunick added, "I point out that benzene is equivalent to asbestos, lead, and formaldehyde as a Group 1 carcinogen; nobody wants to be around the first 2 and the latter is about to be banned by the FDA next month! This breaking news ahead of the AAD 2024 will have profound ramifications on clinical practice and how we communicate to our patients about acne topicals, but it is clear that the carcinogen benzene has no place in everyday consumer over the counter or prescription products. Now, we know this includes BPO-containing products."
Bunick will be addressing the topic of BPO and benzene in a lecture at the American Academy of Dermatology Annual Meeting this week in San Diego, California, as part of an acne and rosacea session on Monday, March 11 at 10:40 AM PST.
In a media statement4 in response to the benzene news, Bunick wrote, "I want to reiterate first and foremost that there is not a safe level of benzene that can exist in any skin care product, over-the-counter or prescription. Benzene is highly carcinogenic, and recently we've seen the FDA agree with this position by taking action to ensure removal of carbomers contaminated with benzene from manufacturing processes."
He added, "BPO-containing products are widely used topically for acne vulgaris, folliculitis, hidradenitis suppurativa, and to a lesser extent for rosacea. Most stand-alone BPO formulations used today are obtained over the counter, while BPO-containing prescription products generally combine BPO with another active medicine, such as a retinoid or antibiotic."
In recent years, benzene has been detected in various consumer-facing products, including sunscreens,5 over-the-counter antifungal products,6 antiperspirants,7 and aerosol dry shampoo.8
“The benzene we found in sunscreens and other consumer products were impurities that came from contaminated ingredients; however, the benzene in BPO products is coming from the benzoyl peroxide itself,” said David Light, president of Valisure, in the news announcement.1
Valisure's testing also looked at benzene in the air surrounding acne treatments and found that even an unopened Proactiv product leaked high levels of benzene when kept at 104 degrees Fahrenheit, which is the temperature of a hot shower, for approximately 17 hours.
Delayed cancer risk is a real concern, according to Bunick. In a recent publication coming out of the United Kingdom, researchers linked low-level chronic benzene exposure to an increase in mortality. Exposure was low, as few as less than 1 ppm.8
"Millions of patients use over-the-counter or prescription acne products with benzoyl peroxide," Bunick said. "Dermatologists will need to have serious discussions with their patients about the long-term safety risks of using these products having benzene."
This article originally appeared in Dermatology Times.
READ MORE: Dermatology Resource Center
References
4. Bunick C. Carcinogen benzene in acne products containing benzoyl peroxide. Media statement. March 5, 2024. Accessed March 6, 2024.
8. Hyman S, Zhang J, Andersen ZJ, et al. Long-term exposure to air pollution and COVID-19 severity: A cohort study in Greater Manchester, United Kingdom. Environ Pollut. 2023;327:121594. Accessed March 6, 2024. doi:10.1016/j.envpol.2023.121594