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.

La Roche-Posay and Proactiv are among the brands affected. Popular acne treatments were recalled due to potential contamination with benzene. Research shows that long-term exposure to benzene may increase cancer risk. The U.S. Food and Drug Administration conducted benzene testing on the products after third-party testing raised concerns.

Parent company La Roche-Posay has pulled the Effaclar Duo Acne Spot Treatment from L'Oreal's lineup, due to a cancer-causing carcinogen contamination.