lowest observed adverse effect level (LOAEL)

Lowest concentration or amount of a substance, found by experiment or observation, which causes an adverse alteration of morphology, functional capacity, growth, development, or life span of a target organism distinguishable from normal (control) organisms of the same species and strain under defined conditions of exposure.
Source:
PAC, 1993, 65, 2003 (Glossary for chemists of terms used in toxicology (IUPAC Recommendations 1993)) on page 2065
PAC, 2001, 73, 993 (Risk assessment for occupational exposure to chemicals. A review of current methodology (IUPAC Technical Report)) on page 1023
This definition replaces an earlier definition of .