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Open Head vs Closed Head Drums: Which UN Drum Do You Need for Dangerous Goods?
Selecting the correct UN approved drum is one of the most important decisions when shipping dangerous goods. Whether you’re transporting chemicals, paints, adhesives, agrochemicals, pharmaceuticals or hazardous waste, choosing the wrong drum can lead to compliance issues, damaged goods and unnecessary costs.
A common questions we receive is:
“Should I use an open head drum or a closed head drum?”
The answer depends on the type of hazardous material you’re shipping, how it will be filled and emptied, and the applicable dangerous goods regulations.
This guide explains the differences between open head (removable head) and closed head (non-removable head or tight head) drums, when each should be used, and how to choose the correct UN approved packaging for your dangerous goods.
Understanding the Official Terminology
Although many people refer to them as open head and closed head drums, the official UN dangerous goods regulations use slightly different terminology.
Common Industry Term Official UN Terminology
Open Head Drum Removable Head Drum
Closed Head Drum Non-Removable Head Drum
This distinction appears throughout the UN Model Regulations and is reflected in UN packaging codes.
Both designs can be UN approved, but have pros and cons for different applications.
What is an Open Head (Removable Head) Drum?
An open head drum has a completely removable lid that is secured using a fastenings such as bolt ring, lever locking ring or snap on.
Once the fastening is released, the entire top of the drum lifts away, providing unrestricted access to the contents. This design makes filling, emptying and cleaning significantly easier than a closed head drum.
Typical Uses
Open head drums are commonly used for:
• Powders
• Granules
• Solids
• Sludges
• Hazardous waste
• Viscous liquids
• Products requiring manual filling
• Materials that may need inspection after filling
Many businesses handling dangerous goods choose open head drums because they provide flexibility during manufacturing and waste disposal operations.
Advantages of Open Head Drums
Open head drums offer several practical benefits:
• Easy access for filling / emptying
• Simple manual or automated emptying
• Allows for scooping and pouring of contents
• Suitable for solids, pastes and viscous liquids
• Easier internal cleaning and reuse where permitted
• Ideal for hazardous waste collection
• Available in plastic, steel, fibreboard and composite constructions
What is a Closed Head (Non-Removable or Tight Head) Drum?
A closed head drum, also known as a tight head drum, has a permanently fixed top.
Instead of removing the lid, contents are filled and emptied through threaded openings (bungs) located in the top of the drum.
These are commonly supplied with either two openings:
• Large bung
• Small vent or pouring bung
The permanently sealed top provides excellent protection against leakage and contamination.
Typical Uses for Closed Head Drums
Closed head drums are typically used for:
• Chemicals
• Solvents
• Flammable liquids
• Corrosive liquids
• Industrial liquids
• Pharmaceutical ingredients
• Cleaning products
• Oils and lubricants
Because liquids present a higher leakage risk during transport, closed head drums are often the preferred solution.
Advantages of Closed Head Drums
Closed head drums provide several important advantages:
• Reduced leakage risk
• Excellent protection during transport
• Strong structural integrity
• Ideal for pump dispensing
• Better suited to automated filling lines
• Helps protect contents from contamination
Open Head vs Closed Head Drums
Which Drum is Best for Dangerous Goods?
There isn’t a single “best” option.
The correct drum depends on:
• Physical state of the dangerous goods (solid or liquid)
• UN Packing Group (I, II or III)
• Specific UN Number
• Mode of transport
• Filling process
• End-user handling requirements
• Regulatory packing instruction
For example:
Consider an open head drum if you are shipping:
• Powders
• Granules
• Contaminated absorbents
• Hazardous waste solids
• Viscous products
Consider a closed head drum if you are shipping:
• Solvents
• Chemical liquids
• Acids
• Cleaning chemicals
• Hazardous waste liquids
• Industrial liquids
Understanding UN Drum Codes
Every UN approved drum carries a packaging code identifying the material of construction and the drum design.
Examples include:
UN Code Drum packaging type, material and category
1A1 Drum, Steel, Non-Removable Head
1A2 Drum, Steel, Removable Head
1H1 Drum, Plastic, Non-Removable Head
1H2 Drum, Plastic, Removable Head
1G Drum, Fibreboard
6HA1 Composite Plastic Inner with Steel Outer, Drum.
One simple way to remember the difference is:
• 1 = Non-removable head (Closed Head)
• 2 = Removable head (Open Head)
Understanding these codes helps ensure you select the correct packaging for your dangerous goods shipment. You can read more about UN specification marks and how to read them here.
Choosing the Right UN Approved Drum
When selecting packaging for dangerous goods, consider:
• Is the product a solid, liquid or viscous substance?
• What is the UN Number of the hazardous material?
• Which Packing Group applies?
• Is the product chemically compatible with the drum material?
• Will the drum be manually or automatically filled?
• Does the product need to be pumped or poured?
• Can single packaging be used for the application and mode of transport?
• What are the provisions stipulated on the Packing Instructions
Choosing the correct packaging isn’t just about compliance—it’s about protecting people, the environment and your products throughout transport.
UN Approved Drums Available from Air Sea Containers
Air Sea Containers supplies a comprehensive range of UN approved drums suitable for the transport of dangerous goods by road, sea and air.
Our range includes:
• UN Plastic Drums – Lightweight, corrosion-resistant packaging suitable for many hazardous liquids and solids.
• UN Steel Drums – Durable packaging for chemicals, industrial products and hazardous substances.
• UN Composite Drums – Combining a plastic inner receptacle with a steel outer for enhanced protection.
• UN Fibreboard Drums – Lightweight fibre drums for selected dangerous goods and industrial applications.
• UN Tinplate Drums – Compact metal drums suitable for smaller quantities of hazardous materials.
Whether you require an open head drum for hazardous solids or a tight head drum for transporting flammable liquids, our team can help you identify the most suitable UN approved packaging.
Explore our drum ranges:
• UN Fibreboard Drums:
• UN Plastic Drums:
• UN Steel Drums:
• UN Tinplate Drums:
• UN Composite Drums:
Frequently Asked Questions
Is an open head drum suitable for liquids?
Yes, provided the drum has been UN tested and approved for the intended liquid, is correctly closed, and meets the requirements of the applicable dangerous goods regulations. However, many liquid products are more commonly transported in closed head drums because they provide enhanced leak resistance.
What is a tight head drum?
A tight head drum is another name for a closed head or non-removable head drum. The top is permanently fixed, and the contents are accessed through threaded bung openings.
Are open head and closed head drums both UN approved?
Yes. Both drum types are available with UN certification. If the drum has a UN mark then it is UN approved as a single packaging, so no outer packaging is required.
What do 1A1 and 1A2 mean?
These are UN packaging codes for steel drums.
• 1A1 = Steel drum with a non-removable (closed) head.
• 1A2 = Steel drum with a removable (open) head.
The same principle applies to plastic drums:
• 1H1 = Non-removable head.
• 1H2 = Removable head.
What testing has a UN Drum undergone?
There are various performance tests the drum must pass before a drum is given UN certification and a UN Mark.
Tests can differ for material types and substance types. Air Sea Containers has a UKAS approved independent packaging test lab on site, where we can test numerous products, here you can read more about the testing requirements for steel drums and also for fibre drums.
Need Help Choosing the Right Dangerous Goods Drum?
Selecting the correct UN approved drum involves more than simply choosing between an open or closed head design. Factors such as the substance being transported, the UN packing instruction, chemical compatibility and transport mode all play an important role. If you want to know more about the common types of UN approved Drums used for dangerous goods transport you can read more in this article
If you’re unsure which drum is suitable for your application, the dangerous goods specialists at Air Sea Containers can help you identify compliant packaging for your products and transport requirements you can contact us here.
