The new rules will also require sunscreens to have a sun protection factor (SPF) of 15 or more or they won't be able to claim that they help prevent sunburn and possibly reduce the threat of premature skin aging and skin cancer — if used with other measures to protect against the sun. "Sunscreens that meet the new test for Broad Spectrum protection and are also SPF 15 or above can, for the first time, include the statement 'used as directed reduces the risk of early skin aging and skin cancer when used with other sun protection measures,' " Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation, said during a news conference.

The new labels will, for the most part, not be seen until next summer, she said. Sunscreens with a SPF of 2 to 14 can be labeled as "Broad Spectrum," but only those Broad Spectrum products with an SPF of 15 or more can claim they reduce the risk of skin cancer and early skin aging, according to the new regulation. Any sunscreen that is not Broad Spectrum or a Broad Spectrum sunscreen with an SPF between 2 and 14 will have to carry a warning saying the product has not been found to prevent skin cancer or early skin aging. Sunscreens labels will also have a "Drug Fact Box," Woodcock said. And, sunscreens can no longer be called sunblocks, she said, "because we don't want to give the impression that complete protection is provided."

In addition, sunscreens can no longer claim they protect for more than two hours, without approval from the FDA, Woodcock said. The products will also no longer be allowed to state that they are waterproof and sweat-proof. Products can, however, claim to be water-resistant for 40 to 80 minutes. The amount of time the product remains effective must be stated on the label, Woodcock added. One expert applauded the FDA move. "Consumers need simplified and user-friendly guidelines to help them choose an effective sunscreen. The new guidelines will make it easier for dermatologists to make recommendations about sunscreens and for consumers to choose an effective sunscreen to protect their skin," said Dr. Jennifer A. Stein, assistant professor in the department of dermatology at NYU School of Medicine in New York City. "These new guidelines are a major step in the right direction to help better protect Americans from the dangers of sunburn and helping them reduce their risk of developing skin cancer in their lifetime."

Dr. Jeffrey C. Salomon, an assistant clinical professor of plastic surgery at Yale University School of Medicine, said, "The new FDA guidelines for sunscreens reflect the confusion for both consumers and health professionals in the realm of sunscreen efficacy."

"It is welcome news that the term 'Broad Spectrum' now specifically endorses the concept of UVA and UVB protection in a sunscreen product," said Salomon. The FDA is also proposing another rule that would limit the maximum SPF value on sunscreen labels to "50+". The reason: SPF values above 50 have not been shown to give any better protection than an SPF 50 product, Woodcock said.

The agency is asking the public to submit data on the effectiveness and safety of sunscreen sprays and to suggest possible warnings that might be applied to the labels of these products. It is also providing information to the makers of sunscreens to help them comply with the new rules.

Finally, the FDA is starting to look into the safety of the active ingredients in sunscreens, Woodcock said. The American Cancer Society lists skin cancer as the most common of all cancers, responsible for nearly half of all malignancies suffered by Americans. More than 2 million cases of non-melanoma skin cancers are diagnosed each year. Melanoma, the most dangerous form of skin cancer and potentially lethal, is diagnosed nearly 70,000 times each year. Basal cell and squamous cell carcinomas are classified as non-melanomas, usually starting in either basal cells or squamous cells, which are found at the base of the outer layer of the skin or cover the internal and external surfaces of the body. Basal cell or squamous cell cancers are quite curable if detected and treated early, according to the cancer society.