Virginia Law

A. Pesticides that fall within any of the following categories when tested on laboratory animals as specified in subdivision 1, 2, or 3 of this subsection are highly toxic to humans or contain substances or quantities of substances highly toxic to humans within the meaning of the law. Such pesticides shall be referred to as pesticides highly toxic to humans. Upon application and after an opportunity for a hearing, the commissioner may exempt any pesticide from these requirements that is not highly toxic to humans:

1. Oral toxicity. A pesticide that has single dose LD50 of 50 milligrams or less per kilogram of body weight when administered orally to both male and female rats that have been fasted for a period of 24 hours (or to other rodent or nonrodent species specified by the commissioner);

2. Toxicity on inhalation. A pesticide that has an LC50 of 2,000 micrograms or less of dust or mist per liter of air or 200 parts per million or less by volume of a gas or vapor, when administered by continuous inhalation for one hour to both male and female rodent or nonrodent species specified by the commissioner, if he finds that it is reasonably foreseeable that such concentration will be encountered by humans; or

3. Toxicity by skin absorption. A pesticide that has an LD50 of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours with the bare skin of rabbits (or other rodent or nonrodent species specified by the commissioner).

B. Test on other species. Tests on other specified rodent or nonrodent species may be required by the commissioner whenever he finds that tests on other species are necessary to determine whether a pesticide is highly toxic to humans.

C. Terms LD50 and LC50. An LD50, as used in connection with oral toxicity and skin absorption toxicity tests, is the dose that is expected to cause death within 14 days in 50% of the test animals so treated, and LC50, as used in connection with inhalation tests, is also the concentration that is expected to cause death within 14 days in 50% of the test animals so treated.

D. Toxicity based on human experience. If the commissioner finds, after an opportunity for hearing, that available data on human experience with any pesticide indicates a greater toxicity than found in the tests on animals, the human data shall take precedence, and if he finds that the protection of the public so requires, the commissioner shall declare such a pesticide to be highly toxic to humans for the purposes of this law and its regulations.