Mar 6, 2024 - Health

Private lab finds carcinogen in common acne treatments

A researcher in a Valisure lab in New Haven, Connecticut, in September 2022.

A researcher in a Valisure lab in New Haven, Connecticut, in September 2022. Photo: Gabby Jones/Bloomberg via Getty Images

An independent lab asked the U.S. Food and Drug Administration (FDA) in a petition on Tuesday to recall a group of acne products that could potentially contain elevated levels of cancer-causing benzene.

Why it matters: The lab said the carcinogen was present due to the breakdown of benzoyl peroxide, one of the most ubiquitous ingredients in over-the-counter topical acne treatments.

  • Valisure, the Connecticut-based lab, has over the past few years found several cancer-causing substances in common products and medications, including the presence of benzene in hand sanitizers and in spray sunscreens.
  • Its research led to several sunscreen recalls in 2021.

Zoom out: Many federal agencies and international organizations, including the Centers for Disease Control and Prevention and World Health Organization, have classified benzene, a colorless liquid that rapidly evaporates, as carcinogenic.

  • It has been linked to types of blood and lymphatic cancers and has been found to cause cancer if a person is consistently exposed to levels as low as 0.8 parts per million (ppm).
  • The FDA has said benzene should not be used to manufacture any component of a drug product, that manufacturers should not release products that contain benzene above 2 ppm and that they should recall any products with benzene levels above that amount.

How it works: Valisure arrived at its findings by buying 175 common acne treatments, including creams, lotions, gels and washes, and measuring them for benzene.

  • After this initial testing, it found that 94 benzoyl peroxide products also contained the carcinogen, often with values well above 2 ppm.
  • It then measured dozens of the products for benzene after incubating samples at 122°F, which is a common temperature used to test the stability of pharmaceutical products.
  • Valisure found a dramatic increase in benzene levels during incubation, noting that "hundreds" of ppm of benzene can form in just a few weeks at 122°F.

Zoom in: However, benzene levels in some of the products were erratic or diminished over time, leading the research team to hypothesize that the benzene could be leaking from the packaging.

  • It then tested this hypothesis and the results suggested that benzoyl peroxide products could break down into gaseous benzene and emanate into surrounding environments, such as a hot car or a bathroom during a shower.

The big picture: In addition to the recalls, Valisure also called on the FDA to investigate how benzoyl peroxide products are manufactured to develop guidance for testing for benzene in such products.

  • The brands tested by Valisure included Proactiv, Target's Up & Up, Clinique, Clearasil and CeraVe.
  • It's been known since at least 1936 that benzoyl peroxide can degrade into benzene.

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