ET50 : This abbreviation is used for the exposure time required to produce a defined effect when a test population is exposed to a fixed concentration or specified dose of a toxicant
Heriot-Watt University, School of Life Sciences, Some Terms Used In Toxicology and Chemical Safety, Edinburgh, UK 1992. http://www.who.int/ipcs/publications/methods/harmo nization/en/compilation_nov2001.pdf, (Tox and Chem Sfty - Amer) {85}