With countless sunscreens on the market, trying to choose which is the safest and most effective can be overwhelming.

“I tell people to protect their skin every single day with a broad spectrum sunscreen, SPF 30 or higher,” Dr. Elizabeth Hale told CBS News.

Hale said broad-spectrum sunscreens protect from both UVA and UVB radiation.  

“That SPF number, that refers to a product’s ability to block UVB, which are shorter wavelength, and those are the rays that cause sunburn. But every single day, ultraviolet A rays, or UVA, those are longer wavelength,” Hale explained. “Those penetrate every day, year-round, even through windows, through clouds, even in the middle of winter. They can contribute to skin cancer, and otherwise aging of the skin.”

There are two basic types of sunscreen: chemical and mineral. Mineral sunscreens are physical, working like a shield, sitting on the surface of your skin and deflecting the sun’s rays. Their main ingredients are titanium dioxide and zinc oxide, minerals that are classified as “safe and effective” by the Food and Drug Administration.

If you plan to swim or sweat, you may want a chemical sunscreen, which works like a sponge, absorbing the sun’s rays. Although those chemicals — such as oxybenzone — can be detected in the blood weeks after they are used, some doctors say that doesn’t mean they are dangerous.  

However, the FDA says more studies need to be conducted before chemical sunscreens can be deemed safe.

“We recommend that consumers avoid products using oxybenzone,” David Andrews, a senior scientist with the nonprofit Environmental Working Group, told CBS News. “But use is associated with potential impact on our endocrine system and development.”

Nikki Battiste

Nikki Battiste is a CBS News correspondent based in New York.