5 Shocking Sunscreen Facts

06/04/2015 01:10 pm ET | Updated Jun 04, 2016
LiudmylaSupynska via Getty Images

It's the time of year to pull out the sunscreen, but before you do, learn these five shocking sunscreen facts.

1. Sunscreen does not last all day. After you apply a sunscreen, it's ability to protect you from the sun only lasts for about two hours (1). Yes, that's it. Only two hours. If you apply your sunscreen at 9 a.m., it no longer protects you at 11 a.m. So, to be adequately protected from sunburn, skin cancer, and aging including discolorations, you need to reapply sunscreen every two hours.

2. You need to apply sunscreen even on days that you are not going to the beach, pool or are sitting in the sun. Many people think that they only "get sun" when they are at the pool or beach. Actually, sunscreen must be applied everyday that you leave your home during the day to protect your skin. We have learned that you get significant sun expose while doing simple everyday things like driving your car or walking down the street.

3. Most Americans simply don't use sunscreen. A recent study found that only 14 percent of men and 30 percent of women regularly applied sunscreen when out in the sun for an hour (2).

4. Spray sunscreen is potentially flammable. When applying sunscreen spray, stay away from flames (for instance, your barbecue grill), because it has the potential to be flammable. There was a report of a man who caught fire after applying spray-on sunscreen before grilling (3). Another hazard with spray sunscreen is that you can skip areas due to uneven spray application so make sure that you have not missed any areas.

5. If your mineral makeup or powder contains an SPF, you still need to apply a separate SPF. Mineral makeup and powders do not provide an even film over the face, so you protection from the sun is uneven. For adequate protection, use a sunscreen or a facial moisturizer that contains sunscreen (4).

2. Patterns of sunscreen use on the face and other exposed skin among US adults by Dawn M. Holman, MPH, Zahava Berkowitz, MSc, MSPH, Gery P. Guy Jr., PhD, MPH, Nikki A. Hawkins, PhD, Mona Saraiya, MD, MPH, Meg Watson, MPH

Published Online: May 19, 2015. DOI: