Lethal Concentration(50) (LC50) : A calculated concentration of a chemical in air to which exposure for a specific length of time is expected to cause death in 50% of a defined experimental animal population
Department of Health and Human Services (US federal public health agency), The Agency for Toxic Substances and Disease Registry (ATSDR), Glossary (Total Petroleum Hydrocarons), GA, USA 1999. http://www.atsdr.cdc.gov/toxprofiles/tp123-c9.pdf, (Globally Harmonized Sys of Class and Labl of Chem - Brit) {635}