TCDD

The abbreviation stands for TCDD

Compounds such as 2,3,7,8- tetrachlorodibenzodioxin ( known as the Seveso poison since Sevesounglück 1976 in Italy) and 1,3,6,8- tetrachlorodibenzo -p-dioxin, polychlorinated four isomers of the chemicals of dioxins
The Turkish railway company Türkiye Cumhuriyeti Devlet Demiryolları