SPF– Sun Protection Factor.
Melanin is a pigment found in the skin, hair, iris and retina of the eye that protects the skin from damage caused by UV radiation.
UV– ultraviolet radiation.
SPF means the degree of protection only against UVB rays, responsible for the formation of erythema and burns.
PPD (Persistent Pigmentation Darkening) is a protection factor against the formation of permanent pigmentation caused by UVA radiation. PPD is measured by comparing the time spent in the sun needed to cause the skin to darken after applying a sunscreen with the time needed to cause the same change in skin color without the use of the cosmetic.
IPD (Pigment Darkening) determines the effect of UVA rays on the skin after 60 seconds. For example, IPD 10 means 10 percent UVA protection.
UV is divided into three ranges with different wavelengths:
UVC– it is almost completely stopped by the ozone layer.
UVB– `B` as an abbreviation of `burning` (burn)- constitute 5% of ultraviolet radiation reaching the Earth. It is responsible for the erythema, tan, and sunburn. Thanks to them, vitamin D is synthesized in the skin.
UVA– `A` comes from the word `aging`- they are the longest wavelengths. They account for 95% of the ultraviolet radiation present all year round regardless of the weather. It is responsible for the destruction of collagen in the skin, for pigmentation disorders (discoloration), sun allergies, photoaging and skin cancer.
SPF- levels of protection:
In accordance with the recommendations of the European Commission
tanning preparations are divided into 4 levels of protection:
very low protection: SPF 2 and 6;
low protection: SPF 6 and 10;
medium protection: SPF 15, 20 and 25;
high protection: SPF 30 and 50;
very high protection: SPF 50+.
Cream with SPF 15 filters about 93% of UVB rays,
SPF 30- about 97% of UVB rays,
a SPF 50- about 98% of UVB rays.
No product blocks 100% of UVB radiation.
The SPF factor does not block the production of melanin in the skin, which is responsible for the tan effect.
When using products with SPF, melanocytes evenly distribute the pigment between the layers of the epidermis, without external photoprotection, melanocytes themselves try to protect the skin, thus overproducing melanin, which is distributed unevenly and forms clusters- thus leading to discoloration.
SPF protects against burns, irritation, photoaging, the negative effects of UV radiation and reduces the risk of skin cancer.
Phototypes depending on the color of the complexion and the reaction of the skin to the sun:
Phototype I– celtic. Very fair skin, often covered with freckles, light blond or red hair. The skin never tans and burns easily, and is extremely sensitive to the sun.
Phototype II– north european. Light skin, blonde or light brown hair. It burns easily, tans minimally, and is very sensitive to the sun.
Phototype III– central european. Light brown skin, dark blonde or brown hair. It tans slowly, it is possible to obtain a light brown color. It is sensitive to the sun.
Phototype IV– south european. Medium brown, swarthy skin, dark brown or black hair. It tans easily, the risk of burns is minimal.
Phototype V– asian and north african. Dark brown skin, dark or black hair. It tans easily, the skin is resistant to burns.
Phototype VI– african. Dark brown or black skin and hair. The high melanin content protects this phototype from burns.
If you know you’ll burn within 10 minutes without an SPF cream, multiply that number by the SPF number listed on the product.
So 10 minutes multiplied by a sunscreen with an SPF value. For example, 10 minutes x 15 SPF= 150 minutes of protection.
Tips:
Apply sunscreen about 20- 30 minutes before going out in the sun.
Try to apply the product generously.
Reapply the product with SPF every 2 hours and whenever you get out of the water (even when using waterproof products).
Use sunscreen all year round.
Adjust the filter according to your phototype.
What is SPF. Which SPF to choose. Phototypes. UVA UVB UVC UV PPD SPF