27 CFR §19.473

1. (a)General. A proprietor may only use containers that are authorized under this part for containing, storing, transferring, conveying, removing, or withdrawing spirits or denatured spirits.
2. (b)Approval of other containers. The appropriate TTB officer may approve the use of another type of container for a particular purpose in place of a type of container specifically authorized in this part for that purpose if the use of that container:
   1. (1)Will provide protection to the revenue equal to or greater than that provided by the authorized container; and
   2. (2)Will not hinder the effective administration of this part.
3. (c)Approval of other container materials. The appropriate TTB officer may approve the use of a container made of a material other than one prescribed in this subpart if the prescribed material is unsuitable for the intended purpose. If the appropriate TTB officer approves another material for a container, the approval may also specify how the container must be constructed, protected, marked, and used.