Toxicology is the study of the adverse effects of drugs and chemicals on biological systems. It is understood as that branch of science which deals with poisons, and a poison can be defined as any substance that causes a harmful effect when administered, either by accident or design, to a living organism.
Forensic toxicology, is the use of toxicology and other disciplines such as analytical chemistry, pharmacology and clinical chemistry to cases and issues where those adverse effects have administrative or medicoâ€legal consequences, and where the results are likely to be used in court.