Cylinders containing Oxygen, compressed, UN 1072; Compressed gas, oxidizing, n.o.s., UN 3156; Liquefied gas, oxidizing, n.o.s., UN 3157; Nitrogen trifluoride, UN 2451; or Nitrous oxide, UN 1070 must be packaged as required by 49 CFR 173.302(f) and 173.304(f) and be placed in a rigid outer packaging that meets specified flame penetration and thermal resistance requirements as prescribed in Appendices D and E of 49 CFR Part 178. This requirement does not apply to cylinders containing medical-use compressed oxygen transported in accordance with US Variation 15.

An oxygen generator, chemical (as defined in 49 CFR 171.8) may only be transported on cargo aircraft as provided for in 49 CFR 173.168. An oxygen generator, chemical, UN 3356, is not permitted for transport on passenger aircraft unless approved by the appropriate authority of the United States (see US 1). An oxygen generator, chemical, UN 3356, that is transported with a means of initiation attached must be classed and approved by the appropriate authority of the United States (see US 1) in accordance with the procedures specified in 49 CFR 173.56. This includes oxygen generators installed in personal breathing equipment transported in accordance with Special Provision A144 of these Instructions.