About 150 people are suffering from breathing problems after sulfuric acid spilled from a tank belonging to a chemical company in the western city of Oberhausen and turned into a toxic cloud.
Oberhausen firefighters treated most people on the scene on Thursday morning. Four people had to be taken to the hospital.
Firefighters’ spokesman Joerg Preussner said most people had only light breathing troubles, but everyone in the area had been asked to stay inside and close the windows.
Bus lines were stopped and a highway exit was closed to keep people away from the area.
Preussner said it was not yet clear why or how the sulfuric acid had spilled out of a tank, but that firefighters had been successfully fighting the cloud with water mist.