Sunscreen: Can I still use the sun milk from last year?

A half -full bottle of sun milk is hidden in the bathroom cabinet. How is she called to protect the skin from UV rays with strong spring sun on the first few days? Rather not. In old sunscreen there is a risk that it will no longer offer sufficient protection.

Consumers can find how long the sun milk can still be used after opening: mostly on the package inside. An open crucible should be seen on the bottle, for example “12 m”. The sunscreen may be used for a maximum of 12 months after opening. The manufacturer only guarantees an undiminished effectiveness up to this point. If the storage is wrong, the sunscreen can lose its effect faster, for example, if it was exposed to high heat or has driven in the warm car for longer.

The dermatologist Professor Eckhard Breitbart basically advises you to buy a new pack instead of using an old sunscreen. He explains to the “pharmacies Umschau”: If the sun milk bottle is open, oxygen occurs. The oxygen leads to oxidation and this process means that the ingredients change and thus the protective function can no longer be maintained correctly.

Researchers of the Sorbonne and scientists of the National Research Authority CNRS showed in a study in 2021 that there is another problem with the chemical UV filter with the chemical UV filter with longer storage. In a period of one year, the Molecule develops benzophenon in the creams – it may be considered carcinogenic. The fabric can also trigger allergies.

The researchers examined 17 sunscreen with sun protection factor 50. Octocrylen was contained in 16. The scientists: Inside, the sunscreen put in an incubator for six weeks. It was 40 degrees warm and the air humidity was 75 percent. After these six weeks, the creams were in a state that would have been at room temperature even after a year of storage. The researchers found no benzophenone in the sun milk that did not contain octocrylas. The scientists found in the other 16 sunscreens: even in the fresh state 39 mg/kg benzophenon. After the six weeks, the concentration rose almost twice to 75 mg/kg.

According to the NRW consumer center, mineral UV filters such as “Titanium Dioxides” or “Zinc Oxide” are usually more stable and the creams could be used longer. Consumers can see whether a sunscreen contains octocrylas: inside with a look at the ingredients. It says: “Octocrylene”.

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