TCLO 2 : Toxic concentration, low. The lowest airborne concentration which has produced toxic effects in humans or tumorigenic or reproductive effects in animals or humans
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Health and Safety Executive (HSE), HSE Acronyms and Abbreviations, HSE, Merseyside, England, UK 2012. www.hse.gov.uk/acronym/, (Hlth and Sfty - Brit) {716}