The clean-up of a former plant which made horrific German poison-gas shells used in the First World War is complete after 20 years of work, an official told legislators Thursday. The Espagit factory in Hallschlag, Rhineland Palatinate state accidentally exploded in 1920 when an estimated 20,000 poison-gas shells were on the premises. The debris meant the site was an ecological disaster area for decades.

Attacks with gas clouds on enemy lines during the First World War left huge numbers of men maimed or blinded. The Allies also resorted to the tactic. The Chemical Weapons Convention (CWC) now outlaws stockpiling and use of chemical weapons.