The Food and Drug Administration announced recalls of numerous products to treat acne after some of them tested positive for benzene contamination.

"FDA tested a total of 95 acne treatment products containing benzoyl peroxide and found six products with elevated levels of benzene," the FDA said in a statement.

The products include:

The FDA said it conducted its independent tests after a third party raised concerns about elevated levels of benzene in certain acne products containing benzoyl peroxide.

More than 90% of the products the FDA tested had "undetectable or extremely low levels of benzene."

The FDA said Zapzyt Acne Treatment Gel agreed to voluntarily recall its product due to the elevated level of benzene found during its own testing.

What is benzene?

Benzene is classified as a human carcinogen, meaning long-term exposure can increase the risk of leukemia and other blood disorders. According to the American Cancer Society, the chemical is used "mainly to make other chemicals, including plastics, resins, lubricants, rubbers, dyes, detergents, drugs, and pesticides."