A consumer group has asked the government to halt sales of sunscreens and other cosmetics that contain an ingredient the group said can promote cancerous skin tumors.

The Consumer Federation of America said more than a dozen cosmetic products contain urocanic acid, which it said has the potential in sunlight to promote cancer by suppressing the immune system."Ironically, some sunscreen lotions that consumers apply to prevent skin cancer may increase the likelihood of forming cancerous skin tumors," said Mary Ellen Fise, the group's product safety director.

"We believe it is important for consumers to discontinue use immediately of sunscreens and skin care lotions containing urocanic acid," she said.

The federation, joined by two research scientists in the Department of Dermatology at The George Washington University Medical Center, petitioned the Food and Drug Administration on Thursday to halt sales of cosmetics that contain urocanic acid.

The consumer group said voluntary reports to FDA by cosmetic manufacturers in 1989 showed that urocanic acid was being used in 15 products, including 10 sunscreens, 3 body lotions, one makeup base and one makeup foundation.

The FDA had no immediate comment.