Agent orange is a colorless, liquid herbicide used by the U.S. Army during the Vietnam War to reduce foliage of inland forests and coastal mangroves that concealed North Vietnamese fighters. The name comes from the colored stripes emblazoned on the 55-gallon drums in which it was stored and transported.

Agent Orange is a 1:1 mixture of two Phenoxy herbicides: 2, 4-D (2, 4-dichlorophenoxy acetic acid) and 2, 4, 5-T (2, 4, 5-trichlorophenoxy acetic acid). First manufactured in the United States in the 1940s, it became widely used in agriculture by the mid-1950s and continues to be used in various parts of the world. When applied to broadleaf plants, the agent dries out leaves and causes them to drop off, though they usually regenerate within 4–6 months.

U.S. ...