Agent Orange, incineration

Dioxins are sometimes—but rarely—produced in nature, most commonly during volcanic eruptions and forest fires. Their most common source in the environment are industrial reactions in which they occur as by-products of other chemical changes or during the incineration of certain synthetic organic compounds. For example, trace amounts of 2,3,7,8-TCDD occur as an impurity in the herbicide Agent Orange (a mixture of 2,4,5-trichlorophenoxyacetic acid [2,4,5-T] and 2,4-dichlorophenoxyacetic acid [2,4-D]), which was... 

TCDD has no commercial uses but is found as a contaminant. TCDD is present in certain herbicide and fungicide formulations such as 1,4,5-T and in pentachlorophenols. As noted above, it is an unwanted contaminant created by incineration and was a contaminant in Agent Orange. 

During the last decade, various remedial actions were carried out on dioxin-contaminated wastes in the United States and Europe. Historically, building rubble from industrial accidents was used as fill or disposed in the ocean. In 1977, about 2.2 million gallons of Agent Orange and similar herbicide formulations was incinerated on the ship Vulcanus in the Pacific (1). This solution was simplified by the ability to transfer the waste to the ship at a remote location in the Pacific and by the large quantity of liquid waste, which made the incineration on ship economically possible. The destruction efficiency of this at-sea-incineration was about 99.9% according to the limits of analytical detection at that time. 

In 1977, the USAF disposed of the entire stockpile of Agent Orange by high-temperature incineration at sea. The disposal project was accomplished according to requirements of the U.S. Environmental Protection Agency (EPA) under ocean-dumping requirements promulgated under the Federal Water Pollution Control Act. 

Among the chlorinated heterocyclic compounds, chlorinated dibenzodioxins (15) and chlorinated dibenzofurans (16) have received much attention recently because of their high acute toxicity in some systems and their occurrence in the herbicide Agent Orange, in waste oils, and in bleached paper products. The compounds have been observed to be formed in low yields in many combustion-related processes such as municipal waste incineration (Rappe, 1984), and have been measured in ambient air samples by numerous investigators (see, e. g., Czuczwa and Hites, 1986 Marklund et al., 1986). Halogenated PAHs have been identified in flue gas effluents (Eklund and Stromberg, 1983). 

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