human exposure threshold

of toxicological concern
https://doi.org/10.1351/goldbook.15785
Generic value of exposure to a substance, or a group of substances falling within a defined structural class, below which there is expected to be no appreciable risk to human health.
Source:
PAC, 2007, 79, 1153. (Glossary of terms used in toxicology, 2nd edition (IUPAC Recommendations 2007)) on page 1238 [Terms] [Paper]