nuisance threshold

in atmospheric chemistry
That concentration of an @A00194@ that is considered objectionable. In the case of a substance with an objectionable odour, it is the smallest concentration of the substance which can be detected by a human being (nose).
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2203 [Terms] [Paper]