WASHINGTON (AP) – A pair of powerful Democratic senators are prodding the Food and Drug Administration to release tougher standards for sunscreen labels that have been in the works for 30 years.

A bill introduced Friday by Sens. Christopher Dodd and Jack Reed would force the FDA to publish the long-delayed rules that require sunscreens to protect against rays that can cause skin cancer and wrinkles. The agency first announced plans for the rules in 1978.

Most sunscreens effectively block the ultraviolet rays that cause sunburn, called UVB rays. However, many do not defend against UVA rays, which cause tanning but have also been linked to melanoma, the deadliest form of skin cancer.

The FDA last August finally unveiled proposed guidelines that would require sunscreen manufacturers to test their products against UVA rays and detail that level of protection on their labels. At the time, the FDA said it would gather public comments on the proposals before making them binding.

However, the agency is not moving fast enough for some Democrats in Congress.

“Most Americans probably assume their sunscreen protects them from the harmful rays that cause skin cancer,” Rhode Island’s Reed said in a statement. “But unfortunately, with many products, that isn’t the case.”