WASHINGTON -- Help is on the way if you're confused by sun protection numbers and other claims on sunscreens. Starting next summer, you can find SPF 15 bottles and tubes with the label "broad spectrum" and feel confident they're lowering your risk of skin cancer.
Under new rules published Tuesday, sunscreens will have to filter out the most dangerous type of radiation to claim they protect against skin cancer and premature aging.
"Broad spectrum" is the new buzzword from the Food and Drug Administration to describe a product that does an acceptable job blocking both ultraviolet B rays and ultraviolet A rays.
If a sunscreen doesn't protect against both, or the protection factor is below 15, it has to warn: "This product has been shown only to help prevent sunburn, not skin cancer or early skin aging."
The new regulations require that sunscreens be tested for the ability to block the more dangerous UVA rays, which can penetrate glass and pose the greatest risk of skin cancer and wrinkles.
The FDA currently requires testing only for protection against UVB rays, which primarily cause sunburn but can also cause cancer and other damage. That's what the familiar SPF measure is based on.
"For the first time, the FDA has clearly defined the testing required to make a broad-spectrum protection claim in a sunscreen," said Dr. Ronald L. Moy, president of The American Academy of Dermatology Association.
Under the new rules, the FDA will:
- Prohibit marketing claims like "waterproof" and "sweatproof," which the agency said "are exaggerations of performance." Water-resistance claims will be allowed, but companies must explain how much time consumers can expect to get the same benefit while swimming or sweating.
- Cap the highest SPF value at 50, unless companies provide results of testing that support a higher number.
- Require manufacturers to phase out a four-star system used by some companies to rate UVA protection. Instead, protection against UVA should be proportional to protection against UVB, which is already measured using SPF.
SPF measures the amount of sun exposure needed to cause sunburn on UV- protected skin versus unprotected skin. The level of exposure varies by geography, time of day and skin complexion.
There is a popular misconception that SPF relates to time of solar exposure. Many consumers believe that if they normally get sunburn in one hour, then an SPF 15 sunscreen allows them to stay in the sun for 15 hours without burning. This isn't true because SPF is not directly related to length of sun exposure.
The U.S. market for sunscreens has been growing steadily because of worries about cancer and an aging population. It now totals about $900 million annually, according to research firm IBISWorld.
Some consumer advocates complain the agency's final guidelines do not go far enough.
"FDA's rule will allow most products on the U.S. market to use the label 'broad spectrum sunscreen,' even though some will not offer enough protection to assure Americans they can stay in the sun without suffering skin damage from invisible UVA radiation," said David Andrews, senior scientist with the Environmental Working Group.
The FDA is still working on updated guidelines for spray-on products, which use different formulations from other sun-protection solutions.
Most dermatologists recommend a broad spectrum, water-resistant sunscreen of SPF 30 or higher every two hours while outside.
The new labels must be in place by the summer of 2012, said Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation, but the agency hopes that companies will implement them sooner.
Woodcock also said there has been some concern about sunscreens containing nanoparticles of zinc oxide or titanium dioxide that block sunlight. Some critics have suggested that the extremely small particles can penetrate the skin and cause health problems.
But Woodcock said the agency has recently performed animal testing and found that the nanoparticles do not penetrate the skin. The findings "agree with studies published in the literature," she said.
There is currently no evidence to suggest that other chemicals commonly used in sunscreens are dangerous, she said.
An estimated 3.5 million Americans develop skin cancer each year, said Dr. Ronald L. Moy, president of the American Academy of Dermatology. Both skin cancer and melanoma are readily curable if detected early, but melanoma that has spread throughout the body is exceptionally difficult to treat and generally proves fatal, he said.
"Every hour, an American dies of melanoma," he said.
All types of skin cancers are increasing in young people, especially females, Moy said. Researchers attribute that to the propensity of young women to bask in the sun and to use indoor tanning beds.
Nearly $2 billion is spent treating the disease each year, according to the National Cancer Institute.
The academy, Moy said, recommends that people use a sunscreen with an SPF of at least 30. He also noted that most people do not use enough. People should use about 1 ounce to cover their bodies, a glob about the size of a golf ball.
McClatchy News Services contributed to this article.