Children who "cannot be reasonably consulted," such as those that are mentally handicapped or orphaned newborns may be tested on. With permission from the institution or guardian in charge of the individual, the child may be exposed to chemicals for the sake of research.
Parental consent forms are not necessary for testing on children who have been neglected or abused.
Chemical studies on any children outside of the U.S. are acceptable

Read more here: http://www.infowars.com/articles/science/epa_allow_pesticide_testing_on_orphans.htm