Seveso is a small city in northern Italy where on 10th July 1976, after an
explosion at a TCP (trichlorophenol) manufacturing plant, a cloud of chemicals
travelled over parts of the city and some adjacent communities who were exposed
to the chemicals in cloud. 2,3,7,8-TCDD was
one chemical in this cloud.
Dioxin(s) - TCDD
To read about this term in context:
GreenFacts Summary on Dioxins: