Effective Concentration (Ec50) : Concentration of a material in water, a single dose which is expected to cause a biological effect on 50% of a group of test animals
University of Michigan-Flint, Environment Health and Safety Department, MSDS Glossary, University of Michigan-Ann Arbor, Michigan USA 2015, MSDS Terms Glossary is from the University of Oklahoma EHS Department website 2006. http://www.umflint.edu/sites/default/files/groups/ Environment__Health_and_Safety_Department/msds_glo ssary.pdf, (MSDS - Amer) {911}