• History
• Words to Know
• Concerns arise over health effects
• Investigation of health effects
• Ecological effects

Agent Orange is one of several herbicidal (plant-killing) preparations that was used by the U.S. military to destroy forests and enemy crops in Vietnam in the 1960s. Agent Orange was created by mixing equal quantities of two agricultural herbicides commonly used to kill weeds: 2,4-D and 2,4,5-T. Present in the 2,4,5-T as an impurity was 2,3,7,8-tetrachlorodibenzo-p-dioxin (usually abbreviated to TCDD), a dioxin contaminant that is highly toxic to some animals. (Dioxin is a term used collectively for a group of chemical by-products of papermaking and other manufacturing processes.)