Between 1965 and 1968 production of 2,4,5-trichlorophenol in Spolana Neratovice plant in Czechoslovakia seriously poisoned about 60 workers with dioxins; after 3 years of investigation of reasons for health problems of workers, Spolana stopped manufacture of 2,4,5-T (most of which was supplied to the US military in Vietnam).

Several buildings of the Spolana chemical plant were heavily contaminated by dioxins.[50] Unclear amount of dioxins were flushed into the Elbe and Mulde rivers during the 2002 European flood, contaminating the soils.[51] Analysis of eggs and ducks found levels of dioxins 15-time higher then EU limit and high concentrations of dioxin-like PCBs in the village of Libiš.

[52] In 2004, the state health authority published a study which analysed the level of toxic substances in human blood near Spolana. According to the study, blood dioxin levels in Neratovice, Libiš and Tišice were about twice the level of the control group in Benesov.

Quantity of dioxin chemicals near Spolana is significantly higher then background level in other countries, e.g., USA, Japan or Spain.

According to the US EPA, even the background level can pose a risk of cancer from 1:10000 up to 1: 1000, about 100 times higher than normal. [53] The consumption of local fish, eggs, poultry and some produce was prohibited because of the post-flood contamination