The Truth About Sunscreen SPF Numbers

It seems that there is a lot of conversation about sunscreen right now. Here at Westchester Health, we feel that there are a number of important points we want people to remember when they’re buying, applying and reapplying sunscreen in order to avoid sunburn, skin cancer and premature aging of the skin, which we’d like to share here.

Alison F. Stallings, MD, FAAD

Whatever brand of sunscreen you use, it should be:

  • a broad spectrum UVA and UVB sunblock
  • water resistant (they vary between 40- and 80-minute water resistance)
  • an SPF of 30 or higher

Allergic to the ingredients in sunscreen?

Some people have allergies to some of the chemicals in sunscreens. If that is the case, we recommend using a physical sunblock containing titanium dioxide or zinc oxide. Use a sunscreen with the words “sensitive skin” on the label. Avoid products with common allergens such as fragrance, parabens or oxybenzone (benzophenone-2, benzophenone-3, diosybenzone, mexenone, sulisobenzone or sulisobenzone sodium).

SPF number: We recommend at least 30 or higher

Most people aren’t applying the correct amount of sunscreen. Most adults need about one ounce of sunscreen, enough to fill an entire shot glass, to fully cover their body.

SPF numbers can be a little confusing nowadays since there are so many options on the shelves. The SPF number tells you how much UVB light (the burning rays) a sunscreen can filter out.

  • SPF 15: filters 93% of the sun’s UVB rays
  • SPF 30: filters 97% of the sun’s UVB rays

At Westchester Health, we follow the American Academy of Dermatology’s recommendation of using an SPF 30 or higher.

It’s important to know that no sunscreen can filter out 100% of the sun’s UVB rays. That’s why it’s important to also wear protective clothing and seek shade.

When applying sunscreen, don’t forget the non-obvious areas

When you’re putting on sunscreen, make sure you get the tops of your feet, the front and back of your neck, and your ears. Also get the top of your head if it’s exposed.

Read our other dermatology blogs

We’ve written several informative blogs about a variety of skin conditions which you can read here.

Want more information on sunscreens or any other skin issue? Come see us.

If you’d like to learn more about taking good care of your skin, in the sun or at any time, please call (914) 232-1919 and make an appointment to see one of our Westchester Health dermatologists. We’ll go over our best strategies and advice, and take all the time you need to have your questions answered. Our #1 goal is to help you have healthy skin, now and in the future. Whenever, wherever you need us, we’re here for you.

By Alison F. Stallings, MD, FAAD, a Dermatologist with Westchester Health, member of Northwell Health Physician Partners

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