Because sunscreen is now firmly anchored in our savvy vacationer habits, sunscreen is one of our essential summer essentials.
Yet, when you slip it into our bag, a question often comes up: can we reuse the one started last year?
"It's very discouraged," asserts Isabelle Benoit, scientific director Bioderma. And to explain: "In theory, one can use any cosmetic product according to the pictogram stamped on it" (note: this is a logo representing an open jar, in which it is written a number followed by M for months).
Only, in practice ... "solar products are special cosmetics in the sense that they contain sunscreens whose stability can be damaged because of very varied behaviors," she says.
In the sun, adopt the precautionary principle
Indeed, if most of our beauty products are, a priori, kept safe in our bathrooms, a tube of sunscreen can be subject to a lot of climatic and environmental hazards.
"There are those who will leave the tube in full sun on the beach all day, those who will forget in a car ...", Isabelle Benoit list, which continues: "These scenarios various, specific to this type of product , can not be fully represented in our safety, efficacy and aging tests.
For optimal efficiency against UV, it is better to buy a tube of sunscreen adapted to its phototype each summer.
However, it is possible to quickly finish your product once the holidays are over. "Why not use it as a day care until October? "Offers the expert. Enriched with moisturizing agents and anti-free radicals, "it will replace without care a day care until about October".
Expired sun cream: the signs that must alert
In all cases, certain signs visible to the naked eye or remarkable to the touch can determine if a cosmetic product is outdated after opening.
- a phase shift : the fatty phase rises, a liquid similar to water comes out of the product.
- a change in texture : a cream that has lost its suppleness, appears lumpy or curdled.
- a change in color or odor that may indicate bacterial contamination.
- an unusual skin reaction : redness, tingling, overheating, appearance of small pimples, etc.
