For transportation by motor vehicle, substances meeting the conditions for high viscosity flammable liquids as prescribed in § 173.121(b)(1)(i), (b)(1)(ii), and (b)(1)(iv) of this subchapter, may be reassigned to Packing Group III under the following conditions:
a. Packaging must be UN standard metal drums attached with heavy duty steel strapping to a pallet; and
b. The capacity of each drum must not exceed 220 L (58 gallons).