Iowa Administrative Code
Agency 21 - Agriculture and Land Stewardship Department
Chapter 45 - Pesticides
Rule 21-45.21 - Highly Toxic

(1) Oral toxicity. Those which produce death within 14 days in half or more than half the animals of any species at a dosage of 50 milligrams at a single dose, or less, per kilogram of body weight when administered orally to ten or more such animals of each species.

(2) Toxicity on inhalation. Those which produce death within 14 days in half or more than half of the animals of any species at a dosage of 200 parts or less by volume of the gas or vapor per million parts by volume of air when administered by continuous inhalation for one hour or less to ten or more animals of each species, provided such concentration is likely to be encountered by humans when the pesticide is used in any reasonably foreseeable manner.

(3) Toxicity by skin absorption. Those which produce death within 14 days in half or more than half of the animals (rabbits only) tested at a dosage of 200 milligrams or less per kilogram of body weight when administered by continuous contact with the bare skin for 24 hours or less to ten or more animals.

(4) Designation as highly toxic. Provided, however, that the secretary may exempt any pesticide which meets the above standard but which is not in fact highly toxic to humans, from these principles with respect to pesticides highly toxic to humans, and may after a hearing designate as highly toxic to humans any pesticide which experience has shown to be so in fact.

(5) Human data. If the secretary finds, after opportunity for hearing that available data on human experience with any pesticide indicates a toxicity greater than that indicated from the above described tests on animals, the human data shall take precedence and if that protection of the public health so requires, the secretary shall declare such pesticide to be highly toxic to humans for the purposes of this Act and the regulations thereunder