What type of testing is used to determine toxic effects of substances in animals?

Toxicity screening is specifically designed to evaluate the harmful effects of substances on living organisms. This type of testing involves administering varying amounts of a substance to animal models to observe and measure adverse effects, including signs of toxicity, mortality rates, and potential long-term health impacts. Toxicity screening is a crucial aspect of preclinical research, ensuring that any new drugs or chemicals are safe for further testing in humans.

In the context of the other options, behavioral testing assesses how substances affect the behavior of animals and may provide indirect information about toxicity but is not exclusively focused on determining toxic effects. Immunogenicity testing evaluates how well a substance elicits an immune response, which is important for vaccines and biologics, but does not specifically address toxic effects. Pharmacokinetic studies are concerned with the absorption, distribution, metabolism, and excretion of substances within the organism, providing important data for understanding how a substance behaves in the body, rather than explicitly testing for toxicity.