CFR > Title 49 - Transportation > SUBTITLE B—Other Regulations Relating to Transportation > CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (Parts 105–199) > SUBCHAPTER C—HAZARDOUS MATERIALS REGULATIONS (Parts 171–181) > PART 175—CARRIAGE BY AIRCRAFT > SUBPART A—General Information and Regulations (§175.1 to §175.33) > 175.3—Unacceptable hazardous materials shipments.