Which sunscreens work best?

How to be the best consumer you can be.
Aug. 9 2005 7:20 AM

There Goes the Sun

Which sunscreens work best?

Seven years ago, several hours of unprotected sun exposure at an outdoor rock festival left me looking and feeling like a boiled lobster. Thanks to Eastern European ancestry and decades of bookishness, I'm a vaguely pinkish shade of very light blue, and the merest tickle of solar radiation spells trouble for me. But since then, I've taken to carrying a bottle of sunblock with me almost everywhere I go—and I've become something of a sunscreen connoisseur.

Sunscreens (and sunblocks—the names are effectively interchangeable) differ by SPF, or sun protection factor, numbers and active ingredients. SPF refers to the factor by which a sunscreen slows down burning from the UVB range of ultraviolet sunlight; skin coated with sunscreen boasting an SPF of 40 will take 40 times as long as bare skin to burn. While SPF measures only UVB protection, not UVA protection, virtually every commercially available sunblock now claims to protect against both UVA and UVB radiation.

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Sunscreens' active ingredients do one of two things: Chemical screens like octisalate (which blocks UVB) and avobenzone, aka Parsol 1789 (which blocks UVA), absorb UV rays; physical blocks like zinc oxide and titanium dioxide—the white gunk you used to see old people putting on their noses, now micronized so that they disappear into the skin—reflect sunlight altogether. The point is to protect your skin against sunburn and, more important, against squamous-cell and basal-cell carcinoma and melanoma. It's best to apply sunscreen a half-hour before sun exposure and to reapply every few hours if you're swimming: 98 percent of the sun's rays pass through water, so if you go snorkeling without sun protection, you're going to get scorched.

Methodology

In an effort to make sense of the dizzying array of sunscreens on the market, I tested nine varieties, with prices ranging from 81 cents an ounce to more than $10 an ounce. First, and most important, I checked their effectiveness: I applied a different brand every sunny day for several weeks. As it turned out, every sunblock did its primary job fine. (I asked Dr. Walter G. Larsen, a Portland, Ore., dermatologist and skin-cancer expert, if there were particular sunblocks he recommended. "They're all pretty good these days," he shrugged.)

But to ensure my test was foolproof, I applied the nine sunblocks in stripes along my arms. I also hiked up one shirt-sleeve, which gave me a sort of Jennifer-Beals-in-Flashdance look, so that an unprotected shoulder could serve as a control. I spent a while soaking up rays, and after an hour or so, I washed both arms to test water resistance. I then went back outside for another couple of hours, gently humming Michael Sembello's "Maniac" under my breath. Result: one painful, bright-pink shoulder and two arms that were otherwise as pale as when I started. I checked for variation—was one area, perhaps, a little brighter than others?—but found none.

The sunscreens' effectiveness and resistance to water isn't too surprising, given how heavily they're regulated by the Food and Drug Administration. A "water-resistant" sunscreen has to maintain the indicated SPF after 40 minutes in the water, unless it's rubbed off. (Some brands still claim to be "waterproof," but the FDA announced a few years ago that "water-resistant" is more apt, since nothing is entirely waterproof.)

Still, effectiveness isn't the only reason to pick a sunblock—it has to be something you want to slather on your body. My wife and I subjected every formula to the all-important sniff test. Then I gave them the "Is it soup yet?" test: I left the containers in the hot sun for a few hours and checked to see whether the sunscreen turned into runny, scalding liquid, or if it retained a manageably thick texture. Every sunscreen was also tested on an old, unloved T-shirt to see if it would leave a stain. Finally, I considered the additional claims each brand made on its packaging.

The results, from least- to most-satisfying

Click image to expand.

Coppertone Continuous Spray (SPF 30) Price: $9.99 for 6-ounce canister ($1.67 per ounce) Active ingredients: homosalate, octinoxate, octisalate, oxybenzone