U.S. health officials are asking retailers to pull a small number of acne creams from their store shelves after government testing found they contain slightly elevated levels of a chemical associated with cancer.

Acne treatments sold by Proactiv and Walgreens Boots Alliance are being recalled because they are contaminated with a cancer-causing chemical called benzene, the US Food and Drug Administration said Tuesday.

The U.S. Food and Drug Administration issued a recall notice Tuesday for several lots of six products, including Walgreens Acne Control Cleanser, Proactiv Skin Smoothing Exfoliator, SLMD Benzoyl Peroxide Acne Lotion and La Roche-Posay Effaclar Duo Dual Action Acne Treatment.