Study Finds Benzene Forms in Some Acne Products at Relatively Low Temperatures

Researchers call for independent testing of benzoyl peroxide-based acne creams after finding some can develop very high levels of benzene, which is a cancer-causing chemical.

New research raises further concerns about the safety of Proactiv, Clinique, Clearasil and other popular acne products made with benzoyl peroxide, indicating that the chemical compound can transform into benzene when the products reach temperatures that are just slightly warmer than average, potentially resulting in unsafe levels of the cancer-causing chemical.

Last year, the independent testing laboratory Valisure warned about high levels of benzene in acne cream treatments, indicating that some products contain levels of the known human carcinogen that were hundreds of times higher than what is federally allowed.

Benzene is an industrial chemical that has been associated with the development of several fatal forms of cancer, leukemia and other conditions, such as acute myeloid leukemia (AML), Chronic Myelogenous Leukemia (CML), Acute Lymphocytic Leukemia (ALL), Chronic Lymphocytic Leukemia (CLL), Hairy Cell Leukemia (HCL), Non-Hodgkin’s Lymphoma, Multiple Myeloma, Myelodysplastic Syndrome (MDL), Myelofibrosis and Myeloid Metaplasia, Aplastic Anemia and Thrombocytopenic Purpura.

As a result of the prior findings, Valisure filed a citizen’s petition (PDF) with the FDA, calling for regulators to recall acne products that contain benzoyl peroxide, and a number of manufacturers have faced class action lawsuits.

In a new study published last month in the Journal of Investigative Dermatology, researchers from Long Island University tested more than 100 acne products containing benzoyl peroxide, confirming that more than a third contained concerning levels of benzene, which can be incubated at elevated temperatures that are routinely experienced during storage or transport of the products.

Benzoyl Peroxide Becomes Benzene at 122° F

Researchers from Arnold & Marie Schwartz College of Pharmacy and Health Sciences at Long Island University, led by Kaury Kucera, tested the formation of benzene in acne products containing benzoyl peroxide (BPO).

The team tested acne products from various brands and major retailers, including Clean & Clear, Clearasil, Proactiv, La Roche-Posay, Equate, CVS Health and Neutrogena. The products were tested shortly after being purchased from stores in California, Connecticut, Florida, Illinois, New York and Texas.

Samples underwent UV exposure, simulating sunlight exposure, with some generating 4.36 parts per million (ppm) of benzene per hour of exposure.

Overall, more than 34% of products exceeded the FDA’s limit of 2 ppm of benzene. The researchers found that many of the products were substantially contaminated with benzene, with 38 of the products containing concentrations of BPO from 0.16 ppm to 35.30 ppm.

“Our research demonstrates that these products, widely used by consumers of all ages, can potentially contain or generate concerningly high levels of benzene, particularly under common environmental conditions,” the researchers warned.

Researchers tested simulated acne product use at standard body temperatures. At 98.6° F there was no significant effect on benzene concentration. However, when incubated at 122° F benzene formed at consistent levels over time. Benzene accumulated at 9 ppm per day, reaching the 2 ppm limit within 5 hours of incubation. After two weeks the products had 130 ppm of benzene total.

Researchers also tested cold storage and said the findings supported the recommendations issued by the American Acne and Rosacea Society to refrigerate acne products containing benzoyl peroxide.

Kucera’s team said the formulation of the products is “likely the strongest contributor” to higher levels of benzene in drugstore acne products. They also said the findings support the need for independent testing of drugstore products to help keep consumers safe.

Acne Cream Lawsuits

Following the Valisure warnings issued in March 2024, dozens of benzoyl peroxide acne cream lawsuits were filed on behalf of consumers nationwide.

Given common questions of fact and law raised in complaints brought throughout the federal court system, a motion was filed with the U.S. Judicial Panel on Multidistrict Litigation (JPML) to consolidate and centralize the claims before one judge for coordinated pretrial proceedings. However, the panel rejected the request to consolidate the benzene exposure lawsuits in August 2024.

As a result, each of the individual and consumer class action lawsuits are moving forward as individual actions, spread across various different U.S. District Courts.