US BioTek Laboratories

Benzoyl peroxide (BPO) is found in a significant number of over-the-counter (OTC) and prescription acne products, and under heat or prolonged storage, it can degrade into benzene, a chemical classified as a known human carcinogen by the World Health Organization (WHO), the Environmental Protection Agency (EPA), and the National Cancer Institute (NCI). 🧪

⚠️Benzene is not added intentionally.
It forms as a byproduct of BPO breakdown, a process that accelerates with heat exposure, even in unopened products stored above room temperature. 🌡️

Benzene contamination in personal care products is not a new issue. In recent years, voluntary recalls have been issued for sunscreens, hand sanitizers, and antiperspirants found to contain elevated benzene levels, establishing a pattern of concern across product categories.
🧴 In March 2025, the Food and Drug Administration (FDA) tested 95 BPO-containing acne products specifically. Six were found to have elevated benzene levels, and seven voluntary recalls followed, affecting products from brands including La Roche-Posay, Proactiv, Walgreens, and SLMD. 📋

More recently, a class action lawsuit was filed against L'Oréal USA (Grossenbacher v. L'Oréal USA, 2024), alleging that CeraVe BPO products contained benzene levels above the FDA's 2 parts per million (ppm) threshold and that consumers were not informed of this. ⚖️

🔬 It is worth noting that the American Academy of Dermatology (AAD) states that regular use of BPO acne products has not been linked to increased benzene levels in the blood or an increased risk of developing cancer. Research is ongoing.

🌡️ The AAD advises to store products at room temperature or cooler and replace them every 10 to 12 weeks.

US BioTek Laboratories