...
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.
[Amdt. 173–224, 57 FR 45463, Oct. 1, 1992, as amended by Amdt. 173–231, 57 FR 52939, Nov. 5, 1992; Amdt. 173–233, 58 FR 33305, June 16, 1993]