Testing by Valisure, an independent pharmaceutical quality assurance company, has shown that benzene—a known human carcinogen—can form at high levels in benzoyl peroxide (BPO) acne treatment products.
In a press release from Valisure, the company notes their study shows on-market BPO products can form over 800 times the conditionally restricted U.S. Food and Drug Administration (FDA) concentration limit of 2 parts per million (ppm) for benzene. The evidence suggests that this problem applies broadly to BPO products currently on the market.
As part of their research, published in Environmental Health Perspectives (Mar. 14, 2024; 132(3)), the Valisure investigators incubated seven differently formulated and branded BPO products at different temperatures. They incubated at 37°C to simulate standard body temperature, 50°C to evaluate shelf-life performance as an accelerated stability testing temperature for pharmaceuticals, and 70°C to evaluate transportation or passenger vehicle excursion temperature.
High levels of benzene were also detected in the air around incubated BPO products, which Valisure’s release says shows that benzene can leak out of some product packages and pose a potential inhalation risk.
Valisure has launched a citizen petition to the FDA for a recall and suspension of sale for BPO acne products.
There are some limitations to Valisure’s published results that it would be valuable to see more data on, said dermatologist Dr. John Barbieri in a video on his YouTube channel. Dr. Barbieri is a board-certified dermatologist and acne expert at the Brigham and Women’s Hospital and Harvard Medical School in Boston.
Regarding the incubation temperatures, Dr. Barbieri said “Most people aren't storing benzoyl peroxide in these conditions. Now this may replicate what it's like to store benzoyl peroxide at room temperature for long periods of time. But what they don't really have in this report is much data about benzoyl peroxide just off the shelf or when stored at room temperature, what most of us are doing.”
The paper notes that some of the tested BPO products were found to contain benzene at baseline, and others were not. And the amount of benzene found at baseline was not specifically mentioned, Dr. Barbieri said.
He said it would be valuable to know which BPO products did not contain benzene before incubation. “Is there something about the way they're formulated, whether they're a wash or cream or gel? Is it something about other components that help stabilize the benzoyl peroxide that makes these products potentially safer? And this would be really useful for us to be able to advise people on what benzoyl peroxide products are most safe to use.”
This is an unfolding story. Derm.city and The Chronicle of Skin + Allergy will continue to report on developments.