49 CFR §174.106

1. (a)A carrier may not accept for transportation Division 1.1 or 1.2 (explosive) materials, detonators, or detonating primers in any quantity when consigned to “order-notify” or “C.O.D.”, except on a through bill of lading to a place outside the United States.
2. (b)A carrier may not accept for transportation Division 1.1 or 1.2 (explosive) materials, detonators, or detonating primers which the shipper consigns to himself unless the shipper has a resident representative to receive them at the delivery point.
3. (c)A carrier may not accept Division 1.1 or 1.2 (explosive) materials for transportation subject to “stop-off privileges en route for partial loading or unloading.”