Limited Quantities in the IMDG Code
Not every shipment of dangerous goods presents the same level of transport risk. A few small bottles of a flammable liquid packed securely inside a strong outer box create a different transport situation from a 200-litre drum containing the same substance. Dangerous goods regulations recognise this difference through the concept of Limited Quantities, commonly abbreviated as LQ.
Within the International Maritime Dangerous Goods (IMDG) Code, Limited Quantities can provide significant relief from the normal requirements applying to dangerous goods transported by sea. However, the term is sometimes misunderstood. Limited Quantity does not mean that the goods are no longer dangerous, nor does it mean that the IMDG Code can simply be ignored.
Chapter 3.4 establishes a specific regulatory regime. To use it correctly, the shipper must first establish whether the substance is eligible, check the permitted quantity, use appropriate packaging and apply the required marks and transport procedures.
The starting point is column 7a
Whether dangerous goods can be transported as Limited Quantities cannot be determined simply from their class or packing group. The starting point is the individual entry in the Dangerous Goods List in Chapter 3.2 of the IMDG Code.
Column 7a specifies the maximum quantity permitted per inner packaging or article for transport under the Limited Quantity provisions.
The limits differ considerably. Depending on the substance, column 7a may specify quantities such as 100 ml, 500 ml, 1 litre or 5 litres for liquids, or corresponding mass limits for solids. The applicable figure must therefore always be checked against the correct UN number and Proper Shipping Name.
There is also a particularly important value in column 7a: 0.
When “0” is shown, the dangerous goods concerned may not be transported under the Limited Quantity provisions of Chapter 3.4. Reducing the contents to an extremely small package does not change that. The LQ exemption is only available where the Dangerous Goods List expressly provides a quantity greater than zero.
Correct classification therefore comes before any decision to use Limited Quantities.
Limited Quantities is a partial exemption
One of the biggest misconceptions about LQ shipments is that the IMDG Code no longer applies once the goods meet the quantity limit.
That is incorrect.
Chapter 3.4 provides relief from many of the normal IMDG requirements, but it also specifies which provisions remain applicable. These include relevant requirements concerning training, classification, parts of the packing provisions, consignment procedures and certain transport operations.
This distinction is important because Limited Quantity is a method of transporting dangerous goods under simplified provisions. It is not a declaration that the products are ordinary non-dangerous cargo.
The hazard still exists inside the package. The regulatory system simply recognises that appropriately packaged small quantities can present a reduced transport risk.
Inner and outer packaging matter
Most Limited Quantity shipments use combination packaging. This means that the dangerous goods are placed in inner packagings, such as bottles, cans or small receptacles, which are then packed into an appropriate outer packaging.
The quantity specified in column 7a applies to the inner packaging, not to the entire box.
Suppose, for example, that the Dangerous Goods List allows a maximum of 1 litre per inner packaging. A shipper cannot place 5 litres into one bottle merely because that bottle is subsequently packed into a box. Each inner packaging must remain within the specified LQ limit.
Several compliant inner packagings can normally be placed together in one outer packaging, subject to the other applicable conditions.
This makes understanding the distinction between inner packaging, outer packaging and the completed package essential.
The packaging must also be strong enough for the intended transport. Limited Quantity does not justify the use of weak or unsuitable packaging. Packages will still be handled through warehouses, terminals and ports and may spend weeks inside a freight container exposed to vibration, movement and changing climatic conditions.
The 30 kg and 20 kg limits
The completed Limited Quantity package is also subject to gross mass restrictions.
As a general rule, the total gross mass of a package containing dangerous goods in Limited Quantities must not exceed 30 kg. For shrink-wrapped or stretch-wrapped trays, the limit is 20 kg gross mass.
These limits concern the complete package or tray, including the dangerous goods and the packaging materials.
They should not be confused with the quantity limit in column 7a. The two requirements operate at different levels. Column 7a determines the maximum permitted quantity in each inner packaging or article, while Chapter 3.4 separately limits the gross mass of the completed package or tray.
A shipment must comply with both.
This is a good example of why Limited Quantity compliance requires more than looking up a single number in the Dangerous Goods List.
The Limited Quantity mark
Packages prepared in accordance with Chapter 3.4 must generally display the prescribed Limited Quantity mark.
The familiar mark consists of a square set at an angle of 45 degrees, producing a diamond shape, with black upper and lower portions and a contrasting central area. It allows personnel throughout the transport chain to recognise that the package contains dangerous goods being transported under the Limited Quantity provisions.
The mark must meet the dimensional and visibility requirements specified by the Code. Chapter 3.4 also provides for a reduced size where package dimensions require it, subject to the prescribed conditions.
This marking system is deliberately different from the normal class hazard labels used on fully regulated dangerous goods packages.
The distinction matters. Applying a normal Class 3 label to an LQ package simply because it contains a flammable liquid can create incorrect hazard communication if the shipment is being consigned specifically under the Limited Quantity provisions and no other requirement calls for that label.
The package should display the marks required for the regulatory regime actually being used.
What happens when LQ packages enter a container?
Maritime transport adds another important dimension. Individual LQ packages are frequently consolidated into freight containers or other Cargo Transport Units.
Once enough Limited Quantity dangerous goods are loaded into a CTU, additional marking provisions can apply to that unit. Chapter 3.4 contains specific requirements for cargo transport units carrying dangerous goods packed in Limited Quantities.
For freight containers, the required LQ marks may need to be displayed on all four sides. For other cargo transport units, the applicable positioning requirements must be followed.
There is an important mass threshold in this context. The IMDG Code provides relief where the total gross mass of packages containing dangerous goods packed in Limited Quantities does not exceed 8 tonnes per cargo transport unit.
This is a maritime detail that can easily be overlooked by organisations familiar primarily with road transport. A correctly marked individual package does not automatically mean that no additional action is required when hundreds of those packages are consolidated into a sea freight container.
The complete maritime transport operation must be considered.
Documentation still matters
Another frequent assumption is that Limited Quantity shipments never require dangerous goods transport documentation.
For sea transport, that assumption is dangerous.
Chapter 3.4 retains relevant requirements from Chapter 5.4, which means documentation remains part of the IMDG Limited Quantity regime. The transport chain must be provided with the information required to recognise that dangerous goods are being offered under the LQ provisions.
This is particularly important in multimodal transport. A shipment may begin by truck, move through a freight forwarder and terminal and subsequently be loaded aboard a vessel. Different modal regulations may provide different exemptions or documentation arrangements.
The person preparing the shipment should therefore establish which rules apply to every relevant part of the journey rather than assuming that an exemption familiar from road transport applies identically at sea.
Segregation relief is one of the major advantages
One of the practical benefits of Chapter 3.4 concerns segregation.
Dangerous goods packed in Limited Quantities are generally not subject to the normal segregation provisions of Chapter 7.2, including segregation requirements in the Dangerous Goods List, subject to the specific exceptions established by the Code.
This can make a considerable operational difference when consolidating cargo.
However, regulatory relief from IMDG segregation requirements should never be interpreted as permission to pack substances together where they could react dangerously if they leaked.
The general principles of safe packaging and chemical compatibility remain relevant. Two substances that can react violently should not be placed together merely because both qualify for LQ relief.
Regulatory simplification does not replace chemical knowledge.
Training is still required
Limited Quantities are also directly relevant to IMDG training.
Chapter 3.4 does not remove the Chapter 1.3 training requirements. Personnel involved in preparing, packing, documenting, accepting or handling LQ dangerous goods must therefore have training appropriate to their responsibilities.
This is particularly important because LQ shipments are often handled by employees who do not regard themselves as dangerous goods specialists. A warehouse or e-commerce operation may dispatch thousands of small containers of paints, adhesives, aerosols, cleaning chemicals or other regulated products without handling drums or tanks.
The smaller packages can create a false sense that dangerous goods expertise is unnecessary.
In reality, somebody must still determine the correct UN number, verify the LQ allowance in column 7a, ensure that inner packaging quantities comply, select suitable packaging, apply the correct LQ marks and prepare the shipment according to the maritime requirements.
For employees responsible for arranging and documenting dangerous goods shipments by sea, the E-learning IMDG Code Consignor Course (English) available through IMDG-course.com includes documentation and Limited Quantities as part of its function-specific training. Personnel who physically prepare the packages may instead require the dedicated IMDG Packer Course.
Limited Quantity is simple only when the rules are understood
The Limited Quantity provisions are intended to make the transport of small quantities of dangerous goods more proportionate to the risk. When correctly applied, they can reduce marking, labelling, segregation and other regulatory burdens while maintaining an appropriate level of transport safety.
But the simplified regime has clear boundaries.
The substance must first be correctly classified. Column 7a must permit Limited Quantity transport. Each inner packaging must remain within the prescribed quantity limit. The completed package must meet the applicable gross mass limit. Packaging must remain suitable and secure, the correct LQ mark must be applied and maritime-specific requirements for CTUs and documentation must be considered.
The most important lesson is therefore contained in the name itself: Limited Quantity means a limited quantity of dangerous goods. It does not mean limited responsibility.
For shippers, packers and freight forwarders, understanding that distinction is essential to using Chapter 3.4 safely and correctly.
