An LCLo value is the lowest concentration of a material in air reported to have caused the death of animals or humans. The exposure may be acute or chronic. This is also called the lowest concentration causing death, lowest detected lethal concentration, and lethal concentration low. LCLo is closely related to the LC50 value which is the concentration which kills half of the test animals under controlled conditions. This value applies to vapors, dusts, mists and gases. Solids and liquids use the closely related LDLo value for routes other than inhalation.
