Sunscreens become toxic when left on the shelf, study finds

SOME of the world’s most popular sunscreens risk causing cancer if left on the shelf too long because a commonly used sun protection factor breaks down into a harmful ingredient, US and French researchers claim.

If left for a year at room temperature, one of the key ingredients in sunscreens breaks down into benzophenone, a “mutagen, carcinogen, and endocrine disruptor”, the study in the Chemical Research in Toxicology review said.

Scientists at CNRS, the Sorbonne and the Oceanological Observatory in Banyuls-sur-mer in France and the Haereticus Environmental Laboratory in the US, made the discovery after experiments on nine commercial sunscreen products from the EU and eight from the US. Many can be found in the UK.

All but one contain octocrylene, which is present in most sunscreens but also anti-ageing creams, shampoo, tanning oils and conditioners.

While the active ingredient is approved for use in sun protection factor in the US and EU, it is controversial as it poses a risk to marine life and in particular coral reefs, making them more susceptible to bleaching.

As a result, skin products containing the ingredient have been banned in Palau, the Marshall Islands and the US Virgin Islands, and a ban is being debated in Hawaii. Under California Proposition 65, benzophenone is also banned from personal care products, including sunscreens, anti-ageing creams, and moisturisers.

While not outlawed in the EU, the bloc’s Scientific Committee on Consumer Safety last month recommended placing new limits on the use of benzophenone, as well as octocrylene, in cosmetic products compared with current requirements under the European Cosmetics Product Regulation.

Researchers picked the creams at random “directly from stores” after asking for the most popular brands, and artificially aged the products over a sixweek “incubation period”. Only one product contained no octocrylene – Nivea Sun PF 50+. At the end of the ageing process it was found to contain no benzophenone. The others were found to have far higher amounts of benzophenone at the end of the process.

France’s cosmetics federation, FEBEA, said that given all the “extremely strict rules” by European and French health authorities, “all products and ingredients placed on the market are thus safe for health”. It said the SCCS had recently “reaffirmed the safety of authorised doses” of octocrylene and that everything was done “to ensure the quantities are always below toxicity levels”. Despite the US bans, it also said that “the potentially carcinogenic nature of benzophenone has never been demonstrated”.