Quote:... or if it might have been armed with a chemical agent, like phosgene or mustard gas.

"Most of the shells are filled with high explosive or with the toxic load,” in other words, it’s a chemical weapon, “and it's not possible to tell on the outside,” Poelmans said.

So whenever they find a shell, they approach it as a chemical weapon still hazardous to their health. Mustard gas can still cause skin blisters and burns, as well as temporary blindness. Chlorine or Phosgene can be lethal, especially if it gets inhaled.

The possibility of finding such chemical weapons in the fields of Flanders is unique to World War I battlefields — a conflict in which both sides tested new, cruel means to break a costly stalemate.