Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. Toxicology is the study of poisons, or more correctly the study of how chemicals interfere with the normal function of a biological system. According to the 15th century physician and father of toxicology, Paracelsus (1493-1541), “All substances are poisons; there is none which is not a poison. Every substance can be toxic, depending on the dose and frequency of exposure. Current Protocols in Toxicology takes a multidisciplinary approach to providing toxicologists, Living organisms, particularly human are exposed to chemical substances or toxins at least once during the lifetime and it is not without any consequences. Toxicology studies the relationship between the doses of drugs and its effects on living organisms. It is a study that deals with the symptoms, treatments, detection and mechanism of how to cope with it. It particularly emphasizes the amount of chemical exposure and its consequences. Toxicology involves characterizing and quantifying the relationship between exposure to a substance and the nature and magnitude of effects on human health.