Salvage drums have long been used as overpacks for the efficient and effective transport of damaged, defective or leaking containers. However, according to the DOT, salvage drums are NOT to be used as a secondary container, or overpack, for a primary shipment.
Rather, an overpack salvage drum should only be used for damaged, defective, leaking or non-compliant packagings that are discovered after having been placed in transportation.
In 1998, the ‘T’ Salvage drum became the United Nations’ recommended salvage packaging for international use. It is most commonly an 85 US gallon capacity. To bear the UN certification, overpack salvage drums are rigorously tested. They must be able to be dropped 1.2 meters (4 feet) on its most critical orientation without leaking and pass a 30 kPa overall Leakproofness Test. However, while they are certified to hold non-compliant packages in transport, the DOT recommends that, once overpacked in a salvage drum, a non-compliant container should be routed to a facility for disposal or re-containment. You can never be too careful.
And remember, traditional overpack drums are designed to protect non-leaking containers or to be used in a combination pack, they are not certified to hold damaged/non-compliant containers.