The information on the website describes the gases that attached the lungs and respiratory system. It describes how large cylinders were replaced later in the war with gas artillery shells. The author of the book describes the "dull thud of gas shells" which would be accurate. Paul remembers the "gas patients in the hospital who in day-long suffocation cough up their burnt lungs in clots." They wear masks to protect themselves, but that would not have worked if it were mustard gas because it burns any exposed skin.