The Food and Drug Administration Tuesday announced tough new rules for sunscreens designed to help people better protect themselves from the harmful effects of sun exposure, including skin cancer.

The long-awaited regulations will require sunscreens to undergo FDA testing to determine whether they protect against both ultraviolet A (UVA) and ultraviolet B (UVB) rays from sunlight. Those products that pass can be labeled as “Broad Spectrum,” the agency said.

Both UVB and UVA radiation contribute to sunburn, skin cancer and premature skin aging, the agency said, noting that UVB radiation is the primary cause of skin cancer.

Products that have SPF values between 2 and 14 may be labeled as Broad Spectrum if they pass the required test, but only products that are labeled both as Broad Spectrum with SPF values of 15 or higher may state that they reduce the risk of skin cancer and early skin aging, the FDA said. Any product that is not Broad Spectrum, or that is Broad Spectrum but has an SPF between 2 to 14, will be required to have a warning stating that the product has not been shown to help prevent skin cancer or early skin aging, the agency said.

The new requirements, which have been in the works for 33 years, must be on all sunblocks by the summer of 2012, but manufacturers can start using them immediately.

“These changes to sunscreen labels are an important part of helping consumers have the information they need so they can choose the right sun protection for themselves and their families,” Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said in a statement.

The new rules will also bar the use of the terms “sun block,” “waterproof” and “sweatproof,” Woodcock said. Instead, sunscreens can be labeled as “water resistant” and must specify if they work for 40 or 80 minutes, she said. Those that are not water resistant must carry a warning label advising people to use a water resistant product if they are going to be exposed to water or sweat.

The agency also proposed a new regulation that would limit the maximum SPF value on sunscreen labels to “50 +”. The agency said there is insufficient evidence to show that products with SPF values higher than 50 provide greater protection than those with SPF values of 50.

Sunscreen makers could, however, submit data to support including higher SPF values, the agency said.

In addition, the agency will begin accepting data about the safety and effectiveness of sunscreen sprays and comments on possible warnings for sprays.