WHEN the weather finally brightens up, it’s time to put the sunscreen on.

But before you reach for the tube at the back of the cupboard, make sure you check the date on the packaging.

While we might be used to looking at use-by dates on our food, we’re less inclined to look at toiletries as we don’t eat them. A recent study has found that one of the chemicals used in some brands can become carcinogenic over time, meaning keeping a bottle around for too long could be dangerous.

The research, published in the journal Chemical Research in Toxicology, was carried out by scientists in the United States and France. Looking at popular brands including Garnier, Bioderma, LaRoche-Posay, L’Oreal, Coppertone, Banana Leaf and Neutrogena purchased from shops in the U.S. and France, they found octocrylene listed in the ingredients of many.

Using an artificial aging process, they found that over time it can produce another compound called benzophenone, which increases the risk of cancer. The concentration of the chemical increases when the product is kept longer, and the research suggests people to stick to the guidance on the expiry dates on the bottle.

Benzophenone can cause contact dermatitis, and may induce uticaria and anaphylaxis. Absorption of both chemicals through the skin poses a potential threat of toxicities and diseases of other organs.(SD-Agencies)