Benzoyl Peroxide Formulation Characteristics Explain Variation in Benzene Levels

WEDNESDAY, Feb. 19, 2025 (HealthDay News) — Formulation characteristics can explain much of the observed variation in benzene levels of over-the-counter benzoyl peroxide-containing products, according to a research letter published online Feb. 12 in JAMA Dermatology.

John S. Barbieri, M.D., from Brigham and Women”s Hospital in Boston, and colleagues examined the association of formulation with benzene levels of over-the-counter benzoyl peroxide-containing products. The vehicles for 111 products that had their benzene levels examined were evaluated.

The researchers found that leave-on products were associated with significantly lower concentrations of benzene (coefficient, −5.83). No significant association was seen between benzoyl peroxide concentration and benzene concentrations. A weak, but statistically significant, association was seen between days to expiration date and benzene concentration (coefficient, −0.010). Conditions consistent with hot processing were associated with increased benzene concentrations (coefficient, 7.34) in multivariable regression models adjusted for benzoyl peroxide concentration, product type, and days until expiration date. Butylated hydroxytoluene was associated with reduced benzene concentrations (coefficient, −8.15). Benzoic acid was associated with numerically, but not significantly, lower benzene concentrations.

“These results raise important hypotheses for potential strategies to reduce benzene in benzoyl peroxide-containing products, including excipient selection and stricter temperature controls during formulation and distribution,” the authors write.

Several authors disclosed ties to the pharmaceutical and skin care industries.

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