It is important to know that once a certified UN steel drum is manufactured, it can be invalidated, but it never expires! What is critical is that the certification test report is valid when the drums are manufactured. Though certification on the steel drum does not expire, it can be deemed noncompliant if the components used in the drum are not as those specified in the Closure Instructions from the original steel drum manufacturer, or the most recent re-manufacturer.
To fully understand this distinction, drums that are regulated by the DOT, have to be manufactured within 12 months of the Performance Test Report date. If a specific drum is tested on Jan 1, 2018, a manufacturer can continue to manufacture that drum until Dec 31, 2018 under the conditions granted by the Performance Test Report. In order to continue the flow of production, a new replacement test, and Test Report, would have to be in force before Dec 31st 2018, and this would give certification to drum manufactured from the Test date as noted in the Report, for 1 year from that test date. Drums will then have a UN durable mark and permanent mark that indicate the year of manufacture. This is an example of a Performance Test Report.
Once a drum enters use and is in the field, there is no expiration date. However, the drum will always be subject to the closure instruction for that drum. Usually, closure instructions will include an inspection of the gasket or other critical components of the drum. It is the shippers responsibility to be sure that all components are in a like condition as when the drum was new. If DOT were to inspect a 10 year old drum and test it, they would expect it to perform to the original Test Report.
At Skolnik, we keep a list of all our testing expiration dates. This allows our customers to know that the drums they are using regularly have ongoing testing. www.skolnik.com/uncertifications