The amount of radiation blocked by sunscreen: SPF30 is not twice as effective as SPF 15.
A sunscreen with SPF 30 (Sun Protection Factor) allows about 1/30 of UV rays to pass through, blocking about 97%, while a high protection sunscreen with SPF 50 allows about 1/50 of UV rays to pass through, filtering 98%.
Therefore, when the protection factor doubles, the amount of filtered radiation does not double but increases very slowly.
The SPF value indicates how many times longer the skin is protected from sunburn.
A cream with SPF 30 means that you can stay in the sun 30 times longer before getting sunburned than skin that is not protected by any sunscreen.
Why does hair lighten in the sun and skin darken?
When the sun hits your hair, it breaks down the melanin that forms the color, causing it to lighten.
For the skin, however, the opposite occurs. The melanin in the skin acts much like a natural sunscreen, being stimulated by contact with the sun's rays.
When exposed to the sun, the skin undergoes a sudden change and darkens its pigment. In fact, when stimulated by the sun's rays, the skin tells our genes to produce more proteins and therefore more melanin... which is why the skin darkens.
In any case, it is always advisable to use sunscreen that protects both your hair and skin safely and with natural ingredients. Throughout the summer, both your skin and hair need special attention and care because the sun, salt, and chlorine can damage them.
Discover here and in the best salons the sunscreens that best protect your hair and skin....
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