Slip, Slap, Slop: A convenient adage to remember to apply sun protection, but a new study might make you pause before reaching for your coconut sunblock this summer.

Chemists from the the Lomonosov Moscow State University have discovered hazardous compounds form from the breakdown of avobenzone in sunscreen when it interacts with chlorinated water and ultraviolet radiation. A breakdown which may be happening on the wet skin of millions of people around the world who use sunscreen every year.

Avobenzone is the most popular chemical UV filter in use by many cosmetic sunscreen products. Its unique structure allows it to absorb UV light and transform the damaging rays into harmless thermal energy waves. On their own, these sunscreen products are safe, but when exposed to a very common real life mix of chlorinated water and sunlight, they are capable of breaking down into hazardous compounds like phenols and acetyl benzenes, which can provoke liver and kidney dysfunction along with nervous system disorders.

"On the basis of the experiments one could make a conclusion that a generally safe compound transforms in the water and forms more dangerous products," said Dr. Albert Lebedev - one co-author of the study that was published in Chemosphere last month. "In spite of the fact that there are no precise toxicological profiles for the most established products, it's known that acetyl benzenes and phenols, especially chlorinated ones, are quite toxic."  

Research on the transformation of cosmetic products during use is very important as it reveals presumably safe ingredients can become dangerous to our health and should be restricted in cosmetics.

So if you're looking for an alternative this summer, try sunscreens that use zinc oxide as their active ingredient. Or you could make a fashion statement by getting yourself a parasol and wide-brimmed hat.