This method provides information on health hazard likely to arise from short-term exposure to test substance. The determination of sub-chronic oral toxicity using repeated doses may be carried out after initial information on toxicity has been obtained from acute or repeated dose 28-day toxicity tests.
The method is based on the repeated oral administration of the substance of interest over a prolonged period (one dose level daily during 90 days). This Test Guideline is intended primarily for use with non-rodents species. The commonly used non-rodent species is the dog (the beagle is frequently used). At least 8 animals (4 female and 4 male) should be used for each test group. Three concentrations, at least, should be used. The test compound is administered in the diet or in the drinking water, by gavage or in capsules. A limit test may be performed if no effects would be expected at a dose of 1000 mg/kg bw/d. The results of this study include: measurements (weighing at least once a week, food/water consumption) and daily (preferably at the same time) and detailed observations (ophtalmological examination, haematology, clinical biochemistry and urinalysis), as well as gross necropsy and histopathology. A properly conducted 90-day subchronic test should provide a satisfactory estimation of a no-effect level.
