Washington ? Just as millions head to tanning beds to prepare for spring break, the Food and Drug Administration will be debating how to toughen warnings that those sunlamps pose a cancer risk.

Yes, sunburns are particularly dangerous. But there’s increasing scientific consensus that there’s no such thing as a safe tan, either.

The World Health Organization’s cancer division last summer listed tanning beds as definitive cancer-causers, right alongside the ultraviolet radiation that both they and the sun emit. They’d long been considered “probable” carcinogens, but what tipped the scales: An analysis of numerous studies that concluded the risk of melanoma jumps by 75 percent in people who used tanning beds in their teens and 20s.