15 20 30 50 Theres an SPF For Everyone
Sunscreens create a film on the skin that protects it from UVA (responsible for ageing skin) and UVB (responsible for sunburn) rays. They contain several types of filters: chemical filters which absorbs UV and converts it into energy, and/or a physical filter that reflects back the sun's rays.
The SPF (sun protection factor) refers to the UVB and the amount of time before the skin becomes red after exposure. In theory, it takes 10 minutes for the skin to get red. The SPF number of the cream acts as a multiplier of that time. So, SPF 20 increases exposure time by 20 before the skin reddens: 20 x 10 minutes = 3hrs 20mins.
To know which factor to use, you'll need to determine your skin's phototype. This helps determine the skin's response to sunlight and to choose an appropriate SPF.Phototype 1 = Light, freckled skin, blond or red hair. Phototype 1 skin does not tan and easily burns. Recommended sunscreen: SPF 50+.Phototype 2 = Light skin, which reddens after sun exposure, blond or brown hair. Phototype 2 skin is difficult to tan and often gets sunburned. Recommended sunscreen: SPF 50, dropping to 30 after several days' exposure.Phototype 3 = Light skin, blond or brown hair. Phototype 3 skin tans slowly and may occasionally get sunburned. Recommended sunscreen: SPF 30.Phototype 4 = Olive skin that tans well, brown or dark brown hair. Recommended sunscreen: SPF 20. Phototype 5 = Dark skin that tans very easily. Recommended sunscreen: SPF 20, followed by 15.Phototype 6 = Black skin that does not burn. Recommended sunscreen: SPF 15 Whatever sunscreen you choose, it's wise to re-apply it once every 2 hours and after taking a swim. It's also worth using a higher SPF on the face and neck, where the skin is more sensitive.