Fri May 9, 2014 2:50pm EDT

(Reuters) – A judge in Brazil fined Eli Lilly (LLY.N) and a unit of Italy’s ACS Dobfar 1 billion reais ($450 million) and ordered a chemical plant temporarily closed for poisoning workers, Brazilian federal labor prosecutors said on Friday.

The ruling followed a 2008 lawsuit against Eli Lilly and ACS Dobfar subsidiary Antibioticos do Brasil Ltda (ABL) for exposing workers to toxic substances.

Prosecutors accuse Eli Lilly of incinerating toxic waste from third parties, releasing heavy metals and gases that poisoned some of the 500 workers at the Cosmopolis plant, about 140 kilometers north of Sao Paulo.

Prosecutors said 77 of 80 former workers tested for the initial filing presented evidence of poisoning.

Eli Lilly, which made agrochemical products at the plant from 1970 to 2000, said it was appealing the ruling. The company presented its own cleanup plan for chemical byproducts around the plant and said it found no trace of heavy metals.

ABL and privately-held ACS Dobfar, which incorporated the Brazilian firm in 2003, could not immediately be reached for comment.

The judge, Antonia Rita Bonardo, prohibited operations at the plant for a year due to the environmental impact.

($1 = 2.22 Brazilian reais)