the greatest concentration or amount of a substance at which no detectable adverse effects occur in an exposed population, greatest concentration or amount found by experiment or observation, which causes no detectable adverse alteration of morphology, functional capacity, growth, development, or life span of the target organism under defined conditions, aine suurim kontsentratsioon või kogus, mille korral ei esine ainega kokku puutunud populatsioonis täheldatavat kahjulikku toimet