Sun protection factor (SPF) is a measure of how well a sunscreen protects against sunburn, which is most often a result of exposure to ultraviolet B (UVB) rays, the type that cause most skin cancers. Here are some key points to consider when choosing an SPF:
- The American Academy of Dermatology recommends using sunscreen with an SPF of at least 30 or higher.
- Most dermatologists recommend an SPF of at least 30 for most people and most climates.
- Once you go past SPF 30, the protection becomes more incremental. When properly applied, an SPF 30 sunscreen shields skin from about 97 percent of the sun’s UVB rays, while an SPF 50 protects against roughly 98 percent.
- No sunscreen blocks 100 percent of the sun’s rays.
- People with darker skin tones need to use sunscreen (SPF 30 or above) as much as people with lighter complexions.
- For the best protection when youll be outside all day at the pool, park, beach, amusement park or elsewhere, SPF 30 or higher is ideal.
- Higher-number SPFs block slightly more of the sun's UVB rays, but no sunscreen can block 100% of the sun's UVB rays.
It's also important to note that the amount of sunscreen you use is just as important as the SPF number. The average adult needs about one ounce of sunscreen to cover all exposed skin.
