SAE AS452B

The purpose of this standard is to establish optimum standards for crew demand and pressure-breathing oxygen mask assemblies for use by crew members in civil aircraft. This standard covers both general type and quick-donning type mask assemblies in the following classes: a. Class A, oronasal, demand b. Class B, oronasal, pressure-demand c. Class C, full face, demand d. Class D, full face, pressure-demand