Ultraviolet radiation (UV) from sunlight is the primary threat to skin. It is responsible for over 80% of skin aging, and can lead to serious health problems including cancer. There are two types of UV affecting skin, UVA and UVB. UVA penetrates deeper into the skin and is the main cause of skin aging and skin cancer. UVB is the primary cause of sun burn. Active sunscreen ingredients are categorized as either chemical which absorb
UV, or physical which filter UV. Most Dermatologists recommend zinc oxide due to its ability to physically block both UVA and UVB. Sun Protection Factor, or SPF, indicates only the level of UVB protection. It is not a linear scale so there is minimal difference between SPF 15 and SPF 100 (see graph below). In the U.S., there is currently no scale for UVA, the term “Broad Spectrum” is used to indicate UVA protection. Sun protection tips:
- Always apply sunscreen to all exposed skin at least 15 minutes prior to going outdoors.
- Apply a sufficient amount of sunscreen.
- Use SPF 15 or higher Broad Spectrum sunscreen.
- Reapply sunscreen often.
- Wear protective clothing, broad brim hat and sun glasses.
- Avoid sun exposure from 10 a.m. to 4 p.m. when UV is most intense.
- Stay in the shade when possible.