Sunscreen helps prevent skin cancer (and wrinkles), so use it! But what else do you need to know when shopping for sunscreen?

Many of sunscreen’s active ingredients are absorbed through the skin.

Are they safe? The Food and Drug Administration wants to see more research. The FDA has asked companies for more safety data for 12 active ingredients, because they may be absorbed.

Two active ingredients—zinc oxide and titanium dioxide—are not absorbed. But Consumer Reports says that most sunscreens with those active ingredients do not provide as much sun protection, according to the publication’s tests. You can see their recommendations for all types of sunscreens here.

Here’s our guide to sunscreen labels.

Expiration Date

Sunscreens degrade over time. See no expiration date? That means the company has proven that the sunscreen is stable for at least three years.

Broad Spectrum

Look for broad spectrum to block both UVB and some UVA rays (though there’s no SPF rating for UVA, so you don’t know how much is being blocked). The FDA wants all SPF 15-or-higher sunscreens to block some UVA rays and wants higher SPFs to block more.

SPF

The sun protection factor tells you how well a sunscreen blocks UVB rays. The FDA has proposed that labels not exceed SPF 60+ because higher SPFs don’t offer much more protection. Even SPF 30 blocks 97 percent of UVB rays.

Reef Safe

Reef safe usually means no oxybenzone or octinoxate, which can harm coral reefs. But the claim is unregulated, and no sunscreen has been proven safe for all marine life.

Water Resistant

Swimming or sweating? Look for water resistant sunscreen, which retains its SPF value for either 40 or 80 minutes.

PABA Free

Ignore PABA claims. The compound can cause allergic reactions, but it’s rarely used in sunscreens anymore.

Oxybenzone Free

Oxybenzone is readily absorbed and has been detected in human blood, urine, and breast milk. It’s a hormone disruptor in animal studies.


Illustrations: Jorge Bach/CSPI.