Denatonium

Denatonium is an organic ion and one of the bitterest chemical compounds known, with bitterness thresholds of 0.05 ppm for the benzoate and 0.01 ppm for the saccharinate. Commercially, it is usually available in salts such as denatonium benzoate (under trade names such as Denatrol, BITTERANT-b, BITTER+PLUS, Bitrex, Bitrix, Toxishield and Aversion) or as denatonium saccharinate (BITTERANT-s). Denatonium was discovered in 1958 during research on local anesthetics by T. & H. Smith of Edinburgh, Scotland, and registered under the trademark Bitrex. Dilutions of as little as 10 ppm are unbearably bitter to most people. Denatonium salts are usually colorless and odorless solids, but are often traded as solutions. They are used as aversive agents (bitterants) to prevent accidental ingestion. Denatonium is used in denatured alcohol, antifreeze, preventive nail biting preparations, respirator mask fit-testing, animal repellents, liquid soaps, shampoos, and Nintendo Switch game cards to prevent accidental swallowing or choking by children. It is not known to pose any long-term health risks. The name denatonium reflects the substance's primary use as a denaturant and its chemical nature as a cation, hence -onium as a Neo-Latin suffix.