July 8, 2008 -- Questions about sunscreens are plentiful in the wake of a recent report by The Environmental Working Group (EWG) that gave a failing grade to 85% of the nearly 1,000 sunscreens reviewed. The products gave inadequate sun protection, have ingredients thought to be health hazards, or have not been tested for safety, according to scientists at the Washington, D.C.-based nonprofit research organization.
Consumers are understandably confused, with many questions about sunscreen use.
WebMD posed eight key questions about sunscreens to experts, trying to get a consensus on how best to protect the skin from the sun's harmful rays. While the experts don't agree entirely, their answers can give you good guidance to face the sun safely.
1. Do some sunscreen ingredients and products really work better than others?
"A definite yes," says Rebecca Sutton, PhD, a staff scientist for the EWG and an author of the report.
Two ingredients favored by EWG scientists are zinc oxide and titanium dioxide, for two reasons, Sutton says. "They protect us over this broad range of ultraviolet A (UVA) and UVB." And these ingredients don't tend to break down as easily as other sunscreen ingredients, according to the EWG.
UVB rays cause sunburn and skin cancer; UVA rays cause aging and likely skin cancer. Because both cause damage to the skin, Sutton says, it's important to pick a sunscreen with broad spectrum protection that shields out both types of rays.
Many active ingredients in sunscreens break down in the sun, wiping out protection, according to the report. And some sunscreens only provide protection against ultraviolet B.
Zinc oxide and titanium dioxide are classified by experts as physical blockers, which work by reflecting rays away from the skin. Other sunscreen ingredients, such as oxybenzone, are chemical blockers, which work by absorbing rays and preventing them from penetrating.
"The physical blocking sunscreens are by far the better sunscreens vs. the chemical sunscreens," says Sonia Badreshia-Bansal, MD, a dermatologist in Danville, Calif.
Newer sunscreen formulas include the ingredients avobenzone and Mexoryl SX. "These are considered improvements because they provide excellent UVA and UVB protection," says Dina Began, MD, a physician at Montefiore Medical Center and assistant professor of medicine at Albert Einstein College of Medicine in New York.
Mexoryl (ecamsule), a UVA blocker approved in 2006 by the FDA, was judged as effective in a report on the sunscreen ingredient in a study published in Plastic and Reconstructive Surgery in 2007.
But the EWG found in its literature search that as much as 40% of Mexoryl can degrade within two hours, Sutton says.
Another new sunscreen addition, Helioplex, is a stabilizer used in sunscreens that combine avobenzone (a UVA sunscreen) and oxybenzone (a sunscreen that blocks UVB and some UVA). While they may be more stable, Helioplex products trigger the same concerns from EWG scientists as do other chemical blockers -- the risk of upsetting hormonal balance, Sutton says.
The bottom line: Physical blockers work better on both UVA and UVB rays, according to experts interviewed by WebMD.
2. Do some sunscreen ingredients really carry health risks?
Experts disagree, with some thinking they do and others saying the link is unproven.
Sutton thinks some ingredients are definitely hazardous, including oxybenzone. "We have animal studies that indicate we should be concerned about hormone disruption," she says. "Oxybenzone is found to have weak estrogenic effects in fish."
What some experts suspect happens is that the body interprets the presence of the chemical as some sort of hormone. "It could be turning on or off certain functions," she says. "The hormonal balance is becoming disrupted."
In laboratory studies, some sunscreen ingredients, including Padimate-O and Ensulizole, have been linked to cell mutations that can be linked to cancer, Sutton says.
But the official stance of the Skin Cancer Foundation is that oxybenzone is a "safe and effective UV filter," according to a spokesperson.
The American Academy of Dermatology has no official position on the use of oxybenzone sunscreens, a spokesperson says.
3. What do I look for when I go sunscreen shopping?
Sunscreens using physical blockers (titanium dioxide, zinc oxide) are preferred by EWG scientists and the doctors interviewed by WebMD.
For shopping help, see EWG's list of recommended brands at www.cosmeticsdatabase.com/special/sunscreens2008. Or ask your doctor to suggest a brand.
Choose a sunscreen with an SPF of 30 or higher, Badreshia-Bansal says. And know that SPF applies only to UVB rays.
4. Which sunscreens are best to use on children and infants?
Best for kids, says Sutton, are sunscreens that contain zinc oxide or titanium dioxide at levels of at least 7% and with an SPF of 30 or higher. "You can typically find the percent on the list of active ingredients on the label," she says.
The sunscreens with physical blockers are preferred for kids, agrees Pat Treadwell, MD, a pediatrician at Riley Hospital for Children in Indianapolis and a member of the executive committee for the dermatology section of the American Academy of Pediatrics. "If there is a generic brand, that should work fine," she says.
According to the American Academy of Pediatrics, parents should keep babies younger than 6 months out of direct sunlight as much as possible. For babies older than 6 months, the Academy recommends using a sunscreen with an SPF of at least 15 on all exposed areas. For babies younger than 6 months, use sunscreen on small areas, such as the backs of the hands and the face if shade or protective clothing aren't options. The Academy recommends broad spectrum products and products with zinc oxide or titanium dioxide for sensitive areas such as nose, cheeks, tops of the ears and shoulders. Some are now available in "fun" colors.
5. Which is better, spray sunscreens or cream sunscreens?
While a spray form of sunscreen is often viewed as more convenient -- especially for hard-to-reach areas -- most experts say creams offer better coverage and are more likely to be used properly.
Sutton has yet another reason to prefer creams. "The problem with sprays and actually with powders is inhalation. You can actually inhale these small particles and they can potentially damage your lungs," she says.
Badreshia-Bansal is not a fan of sprays, either. "It's definitely not the optimal way to put on sunscreens." She offers sunscreen pads with SPF 30, available through physicians, to her patients who hate to put on creams.
But Began doesn't discount spray sunscreens. "I think it's a convenience issue. Some people will find the spray is easier to use. If both are applied in adequate quantity and spread over the surface of the skin, I think you can get comparable results. The spray should be sprayed diffusely. You want an even film on the skin. It is a good idea to rub it in. But it's often used on areas you can't reach. So respray [to be sure you have enough applied]."
6. Why not just cover up with clothing instead?
Clothing helps but won't replace sunscreen, says Treadwell. And not all clothing is created equal when it comes to shielding from the sun's rays. "Clothing works as long as it is a tight weave," she says.
You can test the weave to see if it is tight enough, says Began. "If you shine a strong flashlight through, you shouldn't see light on the other side."
Clothing that is treated to provide sun protection, available at sporting goods stores and online, would be preferred to tightly woven clothing without it, Began says.
7. What about the mess made with sunscreens containing titanium and zinc oxide, especially the stains on clothing and the messy feel?
You may consider spending a little more, says Treadwell. "I would say the brand name ones tend to be a little more elegant, not as thick," she says.
Or you can look on the thickness as a blessing. The physical blocking screens "leave a little sheen on the skin," she says. So it's easy to see where you have missed.
Shop around for different brands, Began says. "Everyone's skin reacts differently to the different vehicles [used in the sunscreens]," she says. "It's like picking a brand of cosmetic."
8. What else should I know about sunscreen, and what else can I do to protect myself from the sun?
Use enough sunscreen, and use it correctly, experts say. "Make sure you are applying at least an ounce to all sun-exposed areas," says Badreshia-Bansal. She recommends reapplying every two hours.
"I recommend my patients put the sunscreen on about 30 minutes to an hour before they go out the door and then reapply again when they are out in the sun," Began says. "And then, if they have a lot of sweating or have done some swimming, anything that may have decreased the concentration, they should reapply it."
You can use the SPF as a rough guide to how long the sunscreen will protect you, she says. If you use a 30 SPF, for instance, and generally burn in 10 minutes without sunscreen, you can expect about 300 minutes or five hours of protection, she says.