Here is the most important thing to remember: a salvage drum is an overpack drum, but an overpack drum can not be a salvage drum. Still confused? Let me explain better.
According to the polyethylene drums of Transportation, 49 CFR 171.8 and overpack is “an enclosure that is used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages. Overpack does not include a transport vehicle, freight container, or aircraft unit load device.”
They are used to contain smaller, non-leaking packages. The package within the overpack must not be compromised and be fully sealed. Examples of these are one or more packages placed or stacked on a pallet and then secured by strapping, shrink wrapping or stretch wrapping. Another is when one or multiple packages are placed in a protective outer package such as a box or crate.
Earlier I stated that a salvage drum is an overpack drum. An example of this is when one or more packages are placed in a salvage drum; this then would constitute this shipment as an overpack.
As for salvages drums, they are designed to hold items or packages that are damaged, defective or leaking. These drums are regulated by the DOT (Department of Transportation) 49 CFR 173.3 which further explains what contents are able to be shipped in a salvage drum. Examples of these shipments would include used sorbents or rags, used to clean or absorb a spill and then transported for proper disposal. It is important to keep in mind that when transporting, the drum must be larger than the item(s) inside the drum itself, thus allowing for safe transporting of the drum and its contents.