PRINCIPLE OF THE TEST
12. The test substance is administered daily in graduated doses to several groups of experimental animals
for a period of 12 months, although longer or shorter durations may also be chosen (see paragraph
Draft consultant’s proposal. V. 8. OECD TG 452 November, 2008
3
30). This duration is chosen to be sufficiently long to allow any effects of cumulative toxicity to
become manifest, without the confounding effects of geriatric changes. Deviations from the exposure
duration of 12 months must be justified, particularly in the case of shorter durations. The test
substance is normally administered by the oral route although testing by the inhalation or dermal route
may also be appropriate (paragraphs 3-4). The study design may also include one or more interim
kills, e.g. at 3 and 6 months, and additional groups of animals may be included to accommodate this
(see paragraph 18). During the period of administration the animals are observed closely for signs of
toxicity. Animals which die or are killed during the test are necropsied and, at the conclusion of the
test, surviving animals are also killed and necropsied.