Sunscreen Buying Guide

Getting started

Choose the wrong sunscreen and you or your kids could get burned. Ultraviolet radiation may promote skin cancer in two ways: by damaging the DNA in skin cells and by weakening the body's natural defenses against cancer cells.

Tested sunscreens have a sun protection factor (SPF) of between 30 and 75+. Most claim "broad spectrum" protection against both ultraviolet A radiation, which tans and ages skin, and UVB radiation, which causes sunburn. All things being equal, if you get a sunburn after 20 minutes without sunscreen, an SPF 30 product would protect you for about 10 hours (20 minutes x 30). But in reality, other factors come into play, such as sun intensity, geographic location, skin type, and whether you've been sweating or swimming,so SPF is simply a relative measure of protection.

How we tested

We tested the sunscreens on people--before and after immersion in fresh water for up to 80 minutes--and on clear plastic plates for a new test mandated by the Food and Drug Administration requiring that products claiming broad-spectrum protection have a minimum "critical wavelength." We also checked whether each product stained cotton, polyester, rayon/spandex, and nylon/spandex.

What we found

Most of the top-selling products we tested protected very well against UVB radiation. And many products were very good at protecting against UVA radiation. But a couple of sunscreens were just OK for UVB protection, and some others were effective when dry but less so after a dunking. Two that claim broad-spectrum protection failed the critical wavelength test and they also did poorly on our UVA test using human volunteers.

No one type protected best, and price had nothing to do with performance.All but one sunscreen stained one or more fabrics.

Sun protection

To stay safe in the sun, wear a hat and protective clothing. When using any sunscreen:

Check ingredients. Oxybenzone may interfere with hormones in the body, and nanoscale zinc and titanium oxides have been linked to potential reproductive and developmental effects. In skin, retinyl palmitate converts readily to retinoids, associated with a risk of birth defects in people using retinoid-containing acne medications. Pregnant women may want to avoid products with retinyl palmitate, noted in the Ratings.
Spray carefully. The FDA has said it is exploring the risks of inhaling spray sunscreens. Avoid using sprays on children, and spray sunscreen onto your hands to apply it to your face.
Use enough. Use 2 to 3 tablespoons of lotion on most of your body, or spray as much as can be rubbed in, then repeat. Reapply every 2 hours and after swimming or sweating.

Bottom line

Any sunscreen you use should be water resistant, with an SPF of at least 30. Above 30, you get little extra protection. See our story on getting the best sunscreen for babies and kids for more information about choosing products for them and how to apply sunscreen properly.