SPF

In winter, an SPF 30 is generally sufficient for daily protection, except in cases of prolonged exposure. In summer, it is preferable to switch to an SPF 50. This also depends on the UV index. If the UV index is 1 and the exposure only lasts for an hour, an SPF 30 is more than adequate.

The SPF 50 provides slightly superior protection compared to SPF 30, blocking approximately 98% of erythemal UV rays as opposed to 97% for SPF 30.

Yes, in the event of prolonged exposure, it is recommended to reapply your sunscreen every two hours, even if it has an SPF of 50 or more.

The SPF measures the filtration rate of erythemal UV rays from a sunscreen, which are composed of 85% UVB and 15% UVA.

If the product is applied in sufficient quantity, it will be equally effective. However, this is rarely the case as it can lead to a pasty and unnatural result.

There is no difference between FPS and SPF. FPS is the French term "Facteur de Protection Solaire" and SPF is the English term "Sunburn Protection Factor".

Yes, clothing with an SPF rating can provide additional protection, especially for exposed areas.

No, the SPFs cannot be added together. However, it may be beneficial to combine skincare products with sunscreens, as a certain amount is required to achieve the protection factor value indicated on the label.

According to some studies, applying sunscreen for several consecutive days prior to UV ray exposure can provide a basic level of skin protection. This might suggest that it is possible to use a product with an SPF 30 after having applied an SPF 50 for several days. However, research on this topic is currently insufficient and, as a precautionary principle, it is recommended to continue using a high SPF throughout the exposure period.