The agency is preparing new labelling information for over-the- counter acne products containing benzoyl peroxide, including Clearasil and Oxy-5, said Dr. Murray Lumpkin, chief of the FDA's anti-infective drug division.

New animal studies sponsored by manufacturers of acne medications are planned to test whether benzoyl peroxide can boost the development of skin cancer that is triggered by sunlight, he said.

"There are teenagers out there who are putting benzoyl peroxide on their faces every day and then going out in the sun and we want to know whether the combination increases their chances of skin cancer," Lumpkin said.