A known human carcinogen, benzene is formed in nature and from human activities. Exposure to it can increase the risk of cancer. Among six products being pulled from shelves are Walgreens Acne Control Cleanser and Proactiv Skin Smoothing Exfoliator.

Elevated levels of benzene were detected in seven acne products distributed to national retailers. Here's what the recall means.

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.