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.

On Tuesday, the U.S. Food and Drug Administration revealed results of new agency testing of over 90 acne products containing benzoyl peroxide for possible benzene contamination. More than 90% of tested products had undetectable or extremely low levels of benzene.

Some acne treatments from brands including Walgreens, Proactiv and La-Roche Posay have been voluntarily recalled for containing elevated levels of the carcinogen benzene, the Food and Drug Administration announced Tuesday.