By contrast, on the 14th day of testing, a Proactiv cream with 2.5 percent benzoyl peroxide tested for nearly 1,800 parts per million of benzene.

Proactiv's 2.5% benzoyl peroxide cream, for example, contained as much as 1,761 parts per million of benzene, while another from Target showed 1,598 parts per million.

Benzene is a chemical used often to make a range of products in the U.S. including detergents, dyes and drugs, according to the U.S. Centers for Disease Control and Prevention.

Proactiv's 2.5% benzoyl peroxide cream, for example, contained as much as 1,761 parts per million of benzene, while another from Target showed 1,598 parts per million.

Proactiv's 2.5% benzoyl peroxide cream, for example, contained as much as 1,761 parts per million of benzene, while another from Target showed 1,598 parts per million.

Proactiv's 2.5% benzoyl peroxide cream, for example, contained as much as 1,761 parts per million of benzene, while another from Target showed 1,598 parts per million.