COVE

This image shows a photo of mask that was later evolved close to the end of the war. Most chemical weapons, such as the mustard gas lost its power as a good weapon by this time. It wasn't as effective because most soldiers were well trained and eqipped with these kind of masks that prevented anything from harming them. Later, they started to ban the use of deadly gas. This had an effect on WWI because the use of chemical weapins went down a whole lot.