The gas masks issued to Australian troops were the same for all Commonwealth soldiers, and many American soldiers. The problem for gas attacks was a real and regular threat. Both sides made use of dangerous gases. The initial threats of gas were from a variety of tear gases, which were easily dealt with, with simple
eye shields.The later, more dangerous gases required a
gas hood which totally covered the head. These would have been very difficult to use in fighting conditions.

This later development had a face mask, held in place by elastic straps across the rear of the head, and a separate filter. The filter was connected to the mask by a long rubber hose, and it was kept in the carry bag, usually strapped to the chest. The face mask was made of a rubber coated material, which, with the passing of time degrades and becomes particularly brittle. The number 3 on the front of the mask indicates the size. This 3 appears to be on a circular section of the mask, this section is where the internal 'nose clip' is fixed. On the inside of the mask there is a spring clip with two rubber pads, the spring is circular, and by gripping the outside of the mask and pressing the sides of the circular spring together forces the rubber pads apart. These are the placed over the nostrils and released, thus holding the noses closed, to prevent the soldier attempting to breathe through his nose. To breath through his mouth the soldier took a rubber mouth piece into his mouth, this was attached to the hose, which went to the filter. On the metal 'L' shaped piece at the front of the mask, there is an outlet valve. This valve was a simply rubber 'duck's bill' which allowed air to pass through it to the outside but not the other way. These masks did leak, therefore it was important that the soldier only breathed through his mouth.

This mask was particularly effective against most gases, but when the gases which had a skin blistering agent were used, the earlier PH helmet was reissued to be carried as well.