Montana Code Annotated
Part 2. Hazardous Substances
50-30-205. Highly toxic defined

50-30-205. Highly toxic defined. (1) "Highly toxic" means a substance that falls within any of the following categories:
(a) produces death within 14 days in one-half or more of a group of 10 or more laboratory white rats each weighing between 200 and 300 grams at a single dose of 50 milligrams or less per kilogram of body weight when orally administered;
(b) produces death within 14 days in one-half or more of a group of 10 or more laboratory white rats each weighing between 200 and 300 grams when inhaled continuously for a period of 1 hour or less at an atmosphere concentration of 200 parts per million or less by volume of gas or vapor or 2 milligrams per liter or less by volume of mist or dust if that concentration is likely to be encountered by humans when the substance is used in a reasonably foreseeable manner; or
(c) produces death within 14 days in one-half or more of a group of 10 or more rabbits tested in 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.
(2) If the department finds that available data on human experience with a substance indicates results different from those obtained on animals in the dosages or concentrations described in subsection (1), the human data must take precedence.
History: En. 69-7102 by Sec. 2, Ch. 394, L. 1975; amd. Sec. 27, Ch. 187, L. 1977; R.C.M. 1947, 69-7102(6); amd. Sec. 1837, Ch. 56, L. 2009.

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