Consumers expect their sun care products to continue to be effective throughout the various situations of everyday life that challenge sunscreens’ persistence. This is, of course, the case at the beach (with swimming, contact with sand and perspiration) and for outdoor sports. But it is also the case for active people who want to protect their face from UV radiation throughout the day, especially in conditions of high heat and relative humidity.
These situations can be combined with other considerations, such as very fair skin, or even children’s delicate skin, increasing the level of requirements.
We must therefore measure the persistence of sunscreens intended to protect the skin in these various situations. It should also be noted that the instruction to reapply sunscreen every two hours may be difficult for athletes such as marathon runners and likewise may not be applicable for day-to-day photoprotection products, which are generally applied once a day, in the morning.
Brands are challenged to meet the specific needs of consumers and therefore