Acne products with benzoyl peroxide may contain the carcinogen benzene, especially if not stored correctly

There is concern over the safety of certain acne products containing benzoyl peroxide, with the U.S. Food and Drug Administration (FDA) having issued a voluntary recall for several products.Posted earlier in March, the statement said the “FDA has concluded that a limited number of products should be recalled at the retail level; more than 90% of tested products had undetectable or extremely low levels of benzene.”Along with a list of six products, a seventh one, Zapzyt Acne Treatment Gel, is being recalled by the manufacturer as a result of the company’s own testing.Canada has been on top of the issue since 2024 when a joint position statement was released by the Canadian Dermatology Association (CDA) and the Acne and Rosacea Society of Canada (ARSC). The purpose was to raise awareness of concerning findings from tests conducted by Valisure, an independent laboratory in the U.S. which tests medications and consumer products.Because of their findings, Valisure issued a citizen petition to the FDA raising concerns about benzene in acne products. The company conducted tests on 66 different benzoyl peroxide products that were incubated at 50°C for 18 days. It included both prescription and over-the-counter products. According to the CDA/ARSC statement, the Valisure tests “detected over 10 parts per million (ppm) of benzene in 42 products, greater than 100 ppm in 17 products and over 1,500 ppm in two products. Incubated benzoyl peroxide products typically displayed an increase in benzene concentration over time and with increased temperature.”It added that the findings suggest that “benzoyl peroxide products on the market could produce substantial amounts of benzene when stored at above-ambient temperatures, such as in a hot car.” According to CDA spokesperson Dr. Alexandra Kuritzky “the real-life meaning of (the Valisure) study is hard to determine” and “the choice to use benzoyl peroxide containing products remains a personal one.”However, people should store the products according to the manufacturers’ recommendations. Products containing benzoyl peroxide should be stored at room temperature, “not in hot cars or hot shower stalls, and discarded prior to their expiry dates,” Dr. Kuritzky told the Canadian Healthcare Network (CHN).“For those concerned about the possibility of benzene exposure, alternative ingredients for treatment of acne include salicylic acid, glycolic acid and retinoids,” she said. Benzoyl-peroxide containing products are primarily used for acne, and for acne-like conditions such as folliculitis. The compound has antimicrobial activity and can be used in addition to oral antibiotics for acne to help prevent antibiotic resistance. Benzene is a known carcinogen and is on the government of Canada’s list of toxic substances.She noted that the American Academy of Dermatology just released their own position statement. It stated that over 90% of tested products had undetectable or extremely low benzene levels. The risk between these levels of benzene and diseases such as cancer is still being investigated.The bottom line for Dr. Kuritzky is that “benzoyl peroxide is an effective and accessible ingredient to treat acne, and the data suggest that when handled appropriately it presents little risk.” She continues to recommend it in her practice and advises patients to store it correctly. “For patients who are concerned, I recommend the alternatives presented in the position statements: topical retinoids, salicylic acid, glycolic acid, azelaic acid, and seeing a board-certified dermatologist,” she said.Another dermatologistAnother Canadian dermatologist, Dr. Diana Diao, concurs. “Up until this point, clinically, there hasn’t been any concerning red flags about acne products leading to cancer.”But, the amount of benzene present can depend a lot on the formulation of the product. Dr. Diao is a clinical instructor in the department of dermatology and skin science at the University of British Columbia.As well as storing products at room temperature and not in overly warm places, she also advises “discard old products that have been open for a while and definitely don’t use past the expiry date.” A recent research letter on the topic in the Journal of the American Academy of Dermatology (JAAD) concluded that benzoyl peroxide “exposure in patients with acne is not associated with an increased risk of malignancy.”The paper summarized findings from a metanalysis of data from 63 healthcare organizations encompassing over 63,000 acne patients. It noted that benzene can be produced when benzoyl peroxide is exposed to elevated temperatures, in the range of 37°C to 70°C. When asked if there is a potential risk if patients were to apply the products during a heat wave, study coauthor Dr. John Barbieri told CHN that it shouldn’t be a concern. Dr. Barbieri is an assistant professor of medicine at Harvard Medical School.“The rate of meaningful benzene formation is more on the scale of days or weeks rather than hours. In addition, if benzene were to form, since it is highly volatile, much of it would likely go into the surrounding air and not affect the individual,” he said.Health Canada’s responseHealth Canada has not issued a public statement, but did respond to questions from CHN in an email.“Health Canada has been monitoring the U.S. Food and Drug Administration’s (FDA) response to the petition filed by Valisure as a result of the company’s independent testing. The FDA recently completed its own testing and determined that a limited number of products should be recalled. Health Canada continues to monitor and will take immediate action if any products in the Canadian market are implicated,” the response said. It also noted the FDA list of limited voluntary recalls.It added “benzene should be absent from health products except where its unavoidable and in trace, leftover amounts (known as a residual solvent) then it must be restricted to 2 ppm. Health Canada’s approach is consistent with that of the FDA.”Canada does have several prescription and non-prescription drugs containing benzoyl peroxide approved and on the market. “The department will take immediate action to inform consumers if it identifies a risk.”Products listed on the FDA statement. Not all are available in CanadaProduct, lot number(s) and expiration date:La Roche-Posay Effaclar Duo Dual Action Acne TreatmentMYX46WApril 2025Walgreens Acne Control Cleanser23 09328September 2025Proactiv Emergency Blemish Relief Cream Benzoyl Peroxide 5%V3305A; V3304AOctober 2025Proactiv Skin Smoothing ExfoliatorV4204AJuly 2025SLMD Benzoyl Peroxide Acne Lotion2430600March 2025Walgreens Tinted Acne Treatment Cream49707430March 2026

Acne products with benzoyl peroxide may contain the carcinogen benzene, especially if not stored correctly

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