Atrazine

Responding to pressure from environmental groups and the requirements of regulators, the U.S. Environmental Protection Agency (EPA) and a scientific advisory panel have held public hearings on the risks of atrazine, an agricultural pesticide. It's the most commonly used farm chemical in the U.S. and 90 other countries. Atrazine has been banned by the European Union since 2004, and some studies suggest it may be harmful to human health and the environment.

Source: tatoeba (12246447)

A study Kennedy discussed on multiple podcast episodes exposed male African clawed frogs to atrazine in a lab, castrating 75% of the male frogs and turning one in 10 males into females.

Source: wiktionary