When summer rolls around, we’re all reminded to “wear sunscreen!” We’ve all heard about how it’s important to wear sunscreen with a high SPF—but do you really know what SPF means, or why it’s so important? As dermatologists, we see a lot of confusion around SPF and how it protects your skin. So, let’s take a few minutes to break it down.
What Does SPF Actually Mean?
SPF stands for Sun Protection Factor. It’s a measure of how well a particular sunscreen protects your skin from UVB rays, which are the main cause of sunburn and a significant contributor to skin cancer.
If your skin would normally start to burn after 10 minutes in the sun, applying a sunscreen with SPF 30 should theoretically allow you to stay in the sun as much as 30 times longer—up to 300 minutes—without burning. It’s important to note that this is under ideal conditions, with proper application and no sweating, swimming, or wiping it off. That’s why it’s important to choose a sunscreen with a high SPF and to reapply regularly when you are in the sun.
SPF and Broad-Spectrum Sunscreen
While SPF measures a sunscreen’s protection against UVB rays, it doesn’t measure protection against UVA rays. UVA penetrate even deeper into the skin and contribute to premature aging and certain skin cancers. That’s why it’s not enough to just check the SPF: you should always choose a sunscreen labeled “broad-spectrum”, which means it protects against both UVA and UVB rays.
SPF and Skin Cancer Risk
Protecting your skin with a broad-spectrum high SPF sunscreen not only guards against sunburn and skin damage, but also against skin cancer. Skin cancer is the most common cancer in the United States, and much of it is preventable. UV radiation is a proven carcinogen, and regular exposure—even without a sunburn—adds up over time. According to the Skin Cancer Foundation, using SPF 15 or higher daily can reduce your risk of developing squamous cell carcinoma by about 40% and lower your melanoma risk by 50%.
Tips for Choosing Sunscreen
- Go for SPF 30 or higher for daily use.
- Reapply every two hours, and more often after swimming or sweating.
- Don’t forget to apply to commonly missed areas like the ears, lips, neck, and tops of feet.
- Use about one ounce (a little less than a shot glass worth) to cover your body.
The bottom line: SPF is more than just a number; it’s a key tool in protecting your skin’s health. A broad-spectrum, high SPF sunscreen (applied properly) helps prevent sunburn, slows down skin aging, and lowers your risk of skin cancer. Your skin is worth protecting every single day, and daily sunscreen use is really a small way you can protect yourself.
For more tips on sun protection this summer, call Medovate Dermatology at (847) 499 – 5500.