This glossary addresses the need for harmonised toxicology terminology. Fully comprehensive and rigorously reviewed by IUPAC Committees, it serves as the reference glossary for students and researchers in toxicology, and those involved in chemicals legislation, regulation and risk assessment. Toxicology uses terminology from chemistry, medicine, geology, botany, zoology, ecology, and veterinary medicine, as well as some legal terms. Toxicology has become crucial to global trade in chemicals as legislation is increasingly co-ordinated around the world and is based on the classification of toxicity. Consistent terminology is crucial for effective legislation and trade in the modern world.