2,4,5-trichlorophenoxyacetic acid

2,4,5-Trichlorophenoxyacetic acid is a synthetic auxin and chlorophenoxy acetic acid herbicide that was developed in the late 1940s for defoliation and selective control of broad-leafed plants. It was widely used in agriculture until toxicity concerns, particularly contamination with dioxins, led to its phase-out starting in the late 1970s.