ChEBI: 2,4-D is a chlorophenoxyacetic acid that is phenoxyacetic acid in which the ring hydrogens at postions 2 and 4 are substituted by chlorines. It has a role as a synthetic auxin, a defoliant, an agrochemical, an EC 1.1.1.25 (shikimate dehydrogenase) inhibitor, an environmental contaminant and a phenoxy herbicide. It is a chlorophenoxyacetic acid and a dichlorobenzene. It is a conjugate acid of a (2,4-dichlorophenoxy)acetate.