Exhaustion and Malingering
It seems physically impossible for the ordinary man to wear the British mask with its mouthpiece and noseclip more than six to eight hours and vast numbers are unable to even do that. How many thousands of casualties were suffered through men losing their mental balance from exhaustion and the discomfort of the mouthpiece and noseclip no one knows. Such men tore off the mask, stating that they would rather die than endure the torture of wearing it longer. Furthermore, the poor vision of this mask led to the habit of taking the facepiece off while still leaving the mouthpiece and noseclip in place. This gave protection to the lungs, but exposed the eyes, and as mustard gas affects the eyes very readily this alone led to thousands of casualties. There was another interesting side to this situation. The malingerer who wanted to get out of the front line and was willing to take any action, however cowardly, to achieve that end, deliberately removed the facepiece and thus suffered gassing of the eyes. The effect of mustard gas soon became so well known that the malingerer knew gassing of the eyes never resulted in death or permanent loss of sight. With the new type of American mask, the protection of eyes and lungs depends solely upon the fit around the face and no such playing with the mask can be done.
Without going into further details in regard to masks it is sufficient to state that at the end the Americans had produced a mask thoroughly comfortable, giving complete protection against gases and smoke clouds, and one that was easy to manufacture on the huge scale (fifty to seventy-five thousand per day) which was necessary to provide masks for an army of three to four million men in the field.