Sample Chronic Toxicity Tests and Commonly Used Species

Type of Test Feeding (Dietary) Ccmcer Teratogenicity Reproduction  

NOAEL = No-observed adverse effect level. LOAEL = Lowest-observed adverse effect level. 

The main thrust behind these extensive and specific requirements is to enable someone several years from now to reconstruct the history of any specific animal in any test, including dosing regimen, laboratory notes, and lesions and other toxic effects. Given that several hundred animals are required in any one test, this represents a significant level of effort and need for good record keeping. 

Typically, two species are required for a test (e.g., mouse and rat). Both sexes must be tested in equal numbers. Three dose levels are required, plus control animals (i.e., those not given the chemical). Fifty to one hundred animals are required per group, per dose, and per sex. For each species tested, this would include a minimum of four hundred animals, broken down as follows  

For the second species, the same calculations apply. This means that a chronic test conducted under the guidelines presented above (and which are used for cancer studies) would require a minimum of 928 animals. 

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Table 5.4. Sample Chronic Toxicity Tests and Commonly Used Species...

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