Aircraft occupant chemical oxygen system with short and long duration

A chemical oxygen generator comprising:

• a chemical oxygen core including at least one layer of an oxygen-generating composition, the at least one layer comprising:
• a metal powder fuel;
• and
• an oxygen source;
• a perforated metal covering surrounding the chemical oxygen core along a length of the chemical oxygen core, wherein the perforated metal covering comprises an opening ratio of approximately 1 percent to 99 percent;
• a housing having an ignition end, an outlet end, and a housing cavity, wherein the chemical oxygen core and perforated metal covering are positioned within the housing cavity, wherein the chemical oxygen core and perforated metal covering are positioned within the housing, wherein the ignition end comprises an ignition system configured to ignite the chemical oxygen core, and wherein the outlet end is configured to direct oxygen out of the chemical oxygen generator;
• and
• a liner surrounding the perforated metal covering along the length of the chemical oxygen core,
• wherein the liner is a conical metal liner, and
• wherein the chemical oxygen core is configured to produce breathable oxygen gas upon thermal decomposition of the chemical oxygen core.