Beautiful summer having finally arrived, here are two questions that often come up:
1) What does the SPF level of the sunscreen mean?
2) Are all sunscreens equal?
The sun protection factor SPF is the measurement of the relative time it takes to get sunburned with or without sunscreen.
If a person gets sunburned after 5 minutes without any protection, an SPF 15 indicates that it will take 75 minutes (15 times 5 minutes or 1hour and 15 minutes) to get the same sunburn with that sunscreen. Obviously, this is not an exact science and testing is performed under perfect conditions under stable light and with a phenomenal quantity of product. In real life, we must take into consideration many factors such as perspiration, the wind and especially the quantity and uniformity of the product applied. It is absolutely necessary to re-apply sunscreen every two hours because many filters lose their effectiveness after this time.
Are all sunscreens equal?No.
Conventional sunscreens are composed of chemical filters such as oxybenzone, dioxybenzone, etc. They are absorbed into the skin and must be applied 20 to 30 minutes before exposure. Some are possibly allergenic and may provoke irritation or photo allergenic reactions. Many studies are showing that certain chemical filters are estrogenic (female hormone). Also, to be effective, they must be photostable so that they do not deteriorate too fast when affected by UV light. They must be encapsulated to prevent them from penetrating into the skin. Moreover, interactions between the different filters must be avoided. Unfortunately, much of this information is hardly ever indicated on the packaging.
Products that use mineral filters are composed with opaque powders that are reduced to micro particles which reflect the light. The most commonly used are zinc oxide and titanium dioxide. These pigments deflect and diffuse UVA and UVB rays by acting as a mirror. Very safe, they do not penetrate into the skin and may even be used on children. In other words, they are better for the skin and the environment.
Many products contain irritating preservatives that may damage the skin. Also avoid water repellent products, they are certainly practical but also occlusive and intoxicating. As with any product, it is important to read the label. Summer is short. Do not skimp on your sunscreens. The health of your skin is much too important for that.
Lynda Proulx Dermo-Esthéticienne/Phytothérapeute
For the health … of your skin
Telephone. 418.832.0583, Site Web: www.lyndaproulx.com