According to the UV Index Scale, the higher the number on the scale, the more damaging the sun will be to your skin. The UV index is shown as a number between one and 11+, and in Scandinavian countries, the UV index is usually between 4-7 during the summer season and between 0-2 during the winter. At a low UV index, you dont need to use sunscreen, but at a high UV index where the radiation is more intense, you need to protect yourself because a high UV index increases the risk of negative effects.
Dermatologists recommend using a sunscreen with an SPF of at least 30, which blocks 97% of the suns UVB rays. Higher-number SPFs block slightly more of the suns UVB rays, but no sunscreen can block 100% of the suns UVB rays. Sunscreens labeled broad spectrum shield skin from both UVB and UVA rays, and the FDA says that a broad spectrum’s UVA protection level will be roughly proportional to its UVB protection level (SPF rating) .
To ensure adequate protection, it is important to apply sunscreen generously on exposed skin, and to reapply every two hours or after swimming or sweating. Sunscreen expiration dates are typically up to three years, though the best indicator is the “use by” date on a product. When selecting a sunscreen, it is important to choose one that contains active ingredients called UV filters, which protect the skin by absorbing and reflecting harmful UV rays from the sun.
