DOT 49 CFR 173.3:
(c) Salvage Drums. Packages of hazardous materials that are damaged or found leaking and hazardous materials that have been spilled or leaked may be placed in a metal removable head salvage drum that is compatible with the lading and shipped for repackaging or disposal under the following conditions. (Meet 3 psi test)

DOT 49 CFR 173.25:
Authorized Packages & Overpacks
(a) Authorized packages containing hazardous materials may be offered for transportation in an overpack as defined in 171.8 of this subchapter, if all of the conditions are met.

EPA 40 CFR 264.175:
Containment. (a) Container storage areas must have a containment system that is designed and operated in accordance with paragraph (b) of this section.
(b) A containment system must be designed and operated as follows:
(3) The containment system must have sufficient capacity to contain 10% of the volume of containers or the volume of the largest container, whichever is greater. Containers that do not contain free liquids need not be considered in this determination.

OSHA 29 CFR 1910.106 (e)(2)(iii):
Separation and protection. Areas in which flammable or combustible liquids are transferred from one tank or container to another container shall be separated from other operations in the building by adequate distance or by construction having adequate fire resistance. Drainage or other means shall be provided to control spills.

Uniform Fire Code - Division IV,
Section 80.402 (b)(2)(F):
Dispensing and Use - Spill Control, Drainage Control and Secondary Containment. "Rooms or areas where hazardous material liquids are dispensed into containers exceeding a 1-gallon capacity or used in open containers or systems exceeding a 5-gallon capacity shall be provided with a means to control spills. Secondary containment shall be provided when the capacity of an individual container exceeds 55 gallons or the aggregate capacity of multiple containers exceeds 100 gallons."