absolute lethal concentration (LC 100)

https://dx.doi.org/10.1351/goldbook.A00024
Lowest concentration of a substance in an environmental medium which kills 100% of test organisms or species under defined conditions. This value is dependent on the number of organisms used in its assessment.
Source:
PAC, 1993, 65, 2003 (Glossary for chemists of terms used in toxicology (IUPAC Recommendations 1993)) on page 2007