Maximum Allowable Concentration

**Definition:** The maximum exposure to a biologically active physical or chemical agent that is allowed during an 8-hour period (a workday) in a population of workers, or during a 24-hour period in the general population, which does not appear to cause appreciable harm, whether immediate or delayed for any period, in the target population. (From Lewis Dictionary of Toxicology, 1st ed)

**Tree numbers:** - N06.850.460.350.210 - N06.850.460.350.600.615

**Synonyms:** - Maximum Permissible Exposure Level - Maximum Permissible Exposure Concentration - MPEL