How to Choose a Safe & Effective Sunscreen

by Yael Resnick

Everyone wants to use a sunscreen—when it's necessary—that is both safe and effective. That sounds simple, but there are hundreds of sunscreen products out there, and figuring out which ones are actually “safe and effective” can be confusing. Follow these guidelines to choose a sunscreen that will provide the best and safest protection:

• First of all, realize that just because a product is on the shelves, that doesn’t mean it has been in any way tested or approved as safe by the government or anyone else. There are no laws about which ingredients can or cannot be used. In fact, many common ingredients in sunscreens are chemicals that have been found to pose significant health risks. Remember that whatever is put onto your skin will be, to varying degrees, absorbed into your body and into your bloodstream. So you definitely want healthy stuff on your skin!

• There are two types of ultraviolet radiation from the sun’s rays, known as UVA and UVB. Most products now protect against both types of rays, but some only protect against UVB. You want protection from both kinds of ultraviolet rays (the label might read “broad-spectrum”).

• The SPF (Sun Protection Factor) is a measure of how effectively a sunscreen protects against UVB rays (but tells you nothing about UVA). The number tells you how much longer you will be protected, compared to how long you could be in the sun before burning if you did not wear sunscreen. For example, if you would ordinarily get sunburned after 10 minutes, and you use a sunscreen with SPF 15, then you could stay in the sun for an estimated 150 minutes before burning. You should use a product with at least SPF 15—preferably SPF 30. Once you get beyond SPF 30, there is very little additional benefit as you move up to ever-larger numbers. (In fact, products rated with very high SPFs are the subject of some investigation now, because those numbers are deceptive.)

• Avoid sunscreens that contain oxybenzone or Padimate-O, chemicals that have been shown to pose health hazards. (Also avoid products with chemical fragrances.) Instead, choose a sunscreen whose active ingredient is zinc oxide or titanium dioxide. These ingredients work by forming a physical barrier over the skin, rather than chemically interacting with the skin, and they are not absorbed into the skin very much, if at all. So they are far safer.

• Many products with zinc oxide or titanium dioxide contain “nanoparticles”—in other words, super-tiny particles—which may be unsafe when introduced into the body. In tests, however, nanoparticles of these two ingredients did not tend to penetrate skin when applied topically. But avoid sunscreen sprays, since these can allow tiny particles to be inhaled, and absorbed directly through the lungs.

• Avoid sun products that also contain insect repellent. First of all, you will often need bug protection at night, or you might need sun protection at times when there are no bugs—and in either case, you will be applying chemicals you do not need. Also, too much insect repellent may be absorbed into the skin when included in sunscreen products.

• (This next point is the advice of the American Cancer Society, and I am including it here because I think I would be remiss not to. However, there is more than one school of thought about this, so please use your judgment or trust your own health advisor.) Apply sunscreen generously, 30 minutes before going outside, and reapply at least every two hours. Most people only put about half as much on as is needed in order to reach the product’s stated SPF protection.

• For ratings of the safety and effectiveness of hundreds of sunscreens (and other personal care products), go to www.cosmeticsdatabase.com. This is the website of Skin Deep, a research and education project of the Environmental Working Group.