Photolytic method for destruction of dioxins in liquid laboratory waste and identification of the photoproducts from 2.3.7,8-TCDD

Analytical and other research laboratories that generate small volumes of d ioxin-containing wastes have no convenient method for their disposal. We ha ve used ultraviolet photolysis with a low-pressure mercury lamp to destroy dioxin-like compounds, both as individual congeners and in actual waste ana lytical samples, down to nondetect levels. Photolysis promises to be an eff icient, safe, and inexpensive method for on-site treatment of liquid labora tory wastes that are contaminated by dioxin-like compounds, allowing the tr eated materials to be discarded as regular organic solvent waste. Experimen ts with 1,6-[H-3]-2,3,7,8-TCDD revealed that the principal photolytic pathw ay involves cleavage of C-O bonds rather than C-Cl bonds, giving chlorinate d hydroxydiphenyl ethers as the initial products and accounting for the low material balances of reductive dechlorination products previously found up on photolysis of PCDDs. The photolysis products from 2,3,7,8-TCDD do not bi nd to either the Ah receptor or the estrogen receptor in vitro, making it u nlikely that the products from UV treatment of PCDD/PCDF in laboratory wast e will show either Ah or estrogen receptor-mediated toxicological effects.