The North Coast Container Blog

How Steel Drums are Tested to be UN- and DOT-Approved

For companies that use steel shipping drums to transport hazardous materials, including chemicals, sourcing containers that meet United Nations (UN) and Department of Transportation (DOT) regulations is vital for business.

Even for customers who usually ship non-hazardous materials, using UN- and DOT-approved steel shipping drums adds a layer of security in case they may need to ship a small quantity of hazardous materials at some point since they will already have the correct containers.

Steel drum manufacturers like North Coast Container subject their products to rigorous testing to guarantee containers meet UN and DOT regulations, and ensure safety and integrity during transport.

UN and DOT approval of shipping drums is required for commodity items that are tested to the same standards globally. Since DOT regulations in the United States are coordinated with UN requirements, these containers can ship hazardous materials around the world with universal labels and a widespread understanding of the material’s hazard characteristics.

UN and DOT regulations require that each steel drum specification, or design type that NCC makes, must undergo certain qualifications. Essentially, four specific tests – drop test, leak proofness test, hydrostatic pressure test, and stacking test – must be performed annually and recertified every 12 months.

Upon completing these tests, as well as a vibration test, NCC provides its customers a test report demonstrating the certification, showing how each one of the containers performed. The company also provides closure/assembly instructions for each container.

UN and DOT Approval Testing for Quality Steel Drums

The UN and DOT approval testing process involves various performance and quality assessments that guarantee compliance. Below, learn more about each test, including how NCC conducts them.

Drop Tests

A drop test simulates real-life handling conditions to assess leakage and structural failures. To perform this test for every design type, NCC drops three separate containers of each specification, each of which is filled with liquid, at a particular angle as dictated by UN/DOT. The drums must not leak when dropped in that particular direction. Next, three different drums of that same design type are dropped in another direction; again, they must not leak.

The drop test measures how high and how strenuous of a level the container can be dropped from and withstand damage that could cause it to leak. The height can start anywhere from 2.7 feet up to 9 feet. The higher the drop, the more stout the container – and generally speaking, also the more expensive it is. This certification is important to help customers select the right product to meet their needs while being the most cost-effective solution.

Stacking Tests

Stacking tests subject drums to vertical static loads to assess strength and effectiveness. To perform this test, NCC simulates the stacking of material inside its steel shipping drums which would result in a stack that is four drums high. If the stack sits for 24 hours with no deformation and no drums falling, this certification is met.

Leakproofness Tests

NCC performs two leakproofness tests on every one of its steel shipping drum design types: a production test and a design qualification test.

The production test, which is performed during the manufacturing process, verifies that each product will not leak based on a DOT requirement of a minimum PSI rating, as well as a chime cut. At the chime – where the top and the bottom of the drum’s seven layers of steel are rolled together – NCC makes a cut to examine and ensure that the seams are performing appropriately.   Every drum is leakproofness tested during production and a chime cut is administered at the beginning of every construction change. This means that if NCC runs 20 different products on a given day, it performs 20 different destructive chime cuts, ensuring each design type meets the construction approval standard.   

The other leakproofness test is in the design qualification. This is a more strenuous test that requires the drum to be filled with air and submerged in water for 24 hours without a breach. To perform this test, NCC puts a drum’s closures in place, fills the drum with air to 7 PSI, and submerges it in water for the designated period.

Hydrostatic Pressure Tests 

Hydrostatic pressure tests assess a steel drum’s ability to withstand internal pressure when filled with water, essentially testing the integrity of the closure system under pressure. To perform this test, NCC fills the drum with water and then adds air pressure to check and certify how many kilopascals (kPa) can go into the container. NCC’s hydrostatic pressure certifications range from 150-300 kPa. Similar to the drop test certifications, the Hydrostatic pressure test certifications allow customers to select the ideal container that meets their needs, without having to pay more for a stronger, heavier drum they don’t need.

Vibration Tests

While this test is not required annually for every steel drum specification or design type, NCC must have documentation to prove that it does perform and pass vibration testing, which is designed to simulate transportation conditions. To perform the test, NCC fills the drum and places it on a vibration table for a certain period. To pass the test, the drum must have deflection and not have any defamation or container breaches.

NCC’s Packaging Supply Improvement Process

As the largest independent manufacturer of steel drums in North America, and with more than 100 years of experience, North Coast Container’s mission is to be the preferred container supplier to our customers by providing the best quality, value, and service – while leading in safety and sustainability. 

NCC utilizes its Packaging Supply Improvement Process (PSIP) to improve its UN and DOT performances using the same nine-step problem-solving methodology it employs to ensure continuous improvement to better meet customer needs. The process – which includes reason for action, current state, target state, gap analysis, solution approach, rapid experiments, completion plan, metrics, and insights – can result in new, more economical configurations. Improvement opportunities might include reducing the amount of steel, providing cleaner drums, changing a closure, or improving a manufacturing process, for example.

At NCC, the five pillars of our business – quality, value, service, safety, and sustainability – drive everything we do. Our commitment to quality speaks for itself, while our nationwide footprint with redundant capabilities and highly engaged leadership makes us an easy-to-work-with partner. 

We want to help you be proactive; if you’re concerned about any environmental conditions or labeling requirements related to regulatory variances in other countries, or if you have questions about shipping a hazardous substance overseas, reach out to us. Because NCC is solely focused on steel drums, our team likely has an answer or can help you connect with a packaging consultant.

To learn more about NCC products and services, visit our knowledge base of resources.

To learn more about testing requirements, and our certifications, or to find out how to order UN- and DOT-approved steel shipping drums, contact NCC today.

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