Aminocyclopyrachlor belongs to the pyrimidine carboxylic acid chemical family and mimics auxin which is a growth-regulating hormone in dicots including broadleaf terrestrial plants.

[4] This causes undifferentiated cell division and elongation, with resulting appearance characteristic of auxin herbicide damage such as leaf twisting and curling.

Due to the emergence of damage to some conifer species, the United States Environmental Protection Agency and DuPont advised professional applicators and residential consumers to not use Imprelis where Norway spruce or white pine trees are present on or near the property being treated.

[3] [7] Tomato plants are the preeminent bioassay platform for testing auxin herbicide damage because they are extremely sensitive to it.

[12] As a practical matter, all material in AMCP-treated areas should be regarded as permanently poisonous to tomatoes and other nightshades until proven safe.