The sun gives important vitamins such as vitamin D, but it also damages and ages your skin. How long can you healthily stay in the sun? You’ll find out here.
SPF is short for Sun Protection Factor and the number that goes along with it, determines how long you can sit in the sun before the sun causes damage. 100% protection against the sun by sun screen is not possible. Various sun factors do, however, offer high levels of protection. SPF 15 offers 93,3%, SPF 30 offers 96,6% and SPF 50 offers 98% protection. Lower SPFs (2-10) naturally offer lower levels of protection.
Which skin type do I have?
Everyone has a specific skin type. The amount of time you can remain in the sun without getting a sunburn is naturally different for everyone. We differentiate between four skin types: I, II, III and IV
Skin type I
Someone with skin type I has fair skin, has red or blonde hair and has light-coloured eyes. People with skin type I get burned quite quickly and rarely tan. This skin type should use sun screen with a SPF factor 50+, especially children under 16. Their skin is not yet capable to protect optimally against the sun. (Solar power 60)
Skin type II
People with skin type II tend to have fair skin, (dark) blonde hair and blue eyes. They get sunburned quickly and don’t tan easily. Use sun screen with SPF factor 30 to 50. (Solar power 100)
Skin type III
People with this skin type (= Mediterranean type) have a slightly tan skin, dark to brown hair and quite dark eyes. This skin type should use sun screen with a SPF factor 20 to 50. (solar power 200)
Skin type IV
If you have skin type IV, you have tan skin, dark hair and dark-coloured eyes. These people are also called the North-African type. They get sunburned almost never and are naturally tan. (solar power 300)
Solar power number
The classification of your skin type is, on one hand, based on appearance, such as skin, hair colour and eyes, and, on the other hand, the experience you have with tanning and sunburn. Each skin type has a so-called ‘solar power number’. You ened this number to be able to calculate how long you can safely enjoy the sun without getting sunburnt. Each skin type has a personal solar power number:
Skin type I: burns easily, already after 5 to 10 minutes. Solar power number: 60
Skin type II: burns easily as well, after 10 to 20 minutes and tans slowly. Solar power number: 100
Skin type III: burns rarely and tans easily. Solar power number: 200
Skin type IV: burns almost never and tans very well. Solar power number: 300
Once you have determined your skin type, you will also know the solar power number of your skin and you will be able to continue with the next step.
Each day the amount of UV rays that reaches the earth is measured, this is the solar power. You can find these values in weather reports and online. The solar power is indicated on a scale from 1 to 10 and is also called the UV index.
0: no solar power
1-2: almost no solar power
3-4: weak solar power
5-6: moderate solar power
7-8: strong solar power
9-10: very strong solar power
How long can I remain in the sun?
The time you can spend in the sun without getting sunburnt depends on your skin type and the solar power. Divide the solar power number by the expect solar power (UV index) of that day. This helps you know how long you can responsibly stay in the sun. If you for example have skin type II and the solar power is 3 that day, then you divide 100 by 3. This means that you can spend 33 minutes in the sun without any problems, on the condition that you apply sun screen of course. This rule mostly applies during the dangerous hours: between 12 and 15h. If you go into the sun before or after those hours, then you’ll be able to stay a little longer.