A sun exposure limit is a somewhat abstract notion that aims to reflect the amount of ultraviolet light the skin can withstand without too much damage (premature ageing, etc.). It varies greatly from person to person. It depends on our skin type, our medical history and how much time we spend in the sun, among other things. Somebody with light skin has a much lower sun exposure limit than somebody with darker skin. Our limit is like a precious reservoir that is drained a little each time we are exposed to the sun.
All the tips you need to protect your skin
What is a sun exposure limit? What is my own limit?
What is a phototype?
There are six phototypes that are based on skin complexion with or without freckles, hair colour, eye colour, and of course how easily the person tans or experiences sunburn.
What is the Sun Protection Factor (SPF)?
SPF = Sun Protection Factor. It is a measure of the level of protection from UVB rays. Sun protection is grouped into four SPF levels: low: 6 to 10; medium: 15 to 25; high: 30 to 50; very high: 50+. This factor indicates the amount of sunlight that you would have to be exposed to after applying the cream to get sunburned. For example, factor 30 sun cream multiplies by 30 the dose of UVB that would be needed to give you sunburn.
What is the difference between UVA and UVB?
The sun emits various types of light that reach the surface of the Earth: ultraviolet (UV), visible and infrared (IR). UVA, UVB and UVC all have different wavelengths. As a general rule, the shorter the wavelength, the greater its energy.
How long does sun cream remain effective once it has been applied to the skin?
The SPF measures the protection from UVBs. This factor indicates the amount of sunlight that you would have to be exposed to after applying the cream to get sunburned. For example, factor 30 sun cream multiplies by 30 the dose of UVB that would be needed to give you sunburn. The best advice is to reapply every two hours. Did you know? The PAO (period after opening) tells you how long your sun cream will last. If the label says 12M then this means that you can keep your product for 12 months after you first use it.
Will I still tan if I apply sun cream?
It all depends on your skin type. Dark skin that is rick in melanocytes will tan lots and quickly, whereas lighter skin will struggle to tan. It is the same with sun cream: darker skin will tan quickly even through sun cream, and paler skin will tan much more slowly. Applying sun cream will stop you from suffering harmful sunburn. Did you know? Your phototype is the same all over your body. You must therefore protect both your body and your face.
How much must I apply?
Sun cream must be applied to clean, dry skin before exposure to the sun. It is important to reapply your sun cream throughout the day, particularly after swimming, intense sweating or physical activity. It is also important to stress that high-factor sun protection must not encourage users to spend longer in the sun or to reapply less often. In theory, the correct dose is 2 mg of sun cream per 1 cm² of skin. Based on safety assessments, the daily dose is 18 g.
Do children need different sun care products to adults?
Children have barely made a mark on their sun exposure limit. We must help them to protect it by applying sun care products with a high or even very high protection factor (50+).