49 CFR 173.140 : Transportation (§ 1.1 To Parts 1581-1699) — (Parts 100-104 To § 177.870) — Other Regulations Relating To Transportation (Parts 100-104 To § 177.870) — Pipeline And Hazardous Materials Safety Administration, Department Of Transportation (Parts 100-104 To § 177.870) — Hazardous Materials Regulations (§ 171.1 To § 177.870) — Shippers - General Requirements For Shipments And Packagings (§ 173.1 To Appendix H To Part 173) — Definitions Classification, Packing Group Assignments And Exceptions For Hazardous Materials Other Than Class 1 And Class 7 (§ 173.115 To § 173.157) — Class 9 - Definitions.

For the purposes of this subchapter, miscellaneous hazardous material (Class 9) means a material which presents a hazard during transportation but which does not meet the definition of any other hazard class. This class includes:

(a) Any material which has an anesthetic, noxious or other similar property which could cause extreme annoyance or discomfort to a flight crew member so as to prevent the correct performance of assigned duties; or

(b) Any material that meets the definition in § 171.8 of this subchapter for an elevated temperature material, a hazardous substance, a hazardous waste, or a marine pollutant.