Packing dangerous goods for sea transport requires much more than placing packages on a pallet and loading them into a shipping container. Once dangerous goods enter the maritime transport chain, packaging, marking, labelling, segregation, cargo securing and container preparation can all influence whether the shipment can be transported safely and in compliance with the International Maritime Dangerous Goods (IMDG) Code.
For UK manufacturers, exporters, warehouses, freight forwarders and container packing facilities, this makes IMDG training for packers and container loading staff particularly important. These employees perform functions that can directly determine the safety of a dangerous goods shipment before the container ever reaches a port.
The IMDG Code specifically identifies personnel who pack dangerous goods and personnel who load or unload cargo transport units among the shore-based functions requiring training. The training must correspond to the employee’s actual responsibilities.
Why do dangerous goods packers need IMDG training?
The journey of a dangerous goods package often begins inside a factory or warehouse. Before a carrier or shipping line becomes involved, somebody may already have selected the packaging, closed the package, applied markings and labels and combined several packages on a pallet.
Each of those actions matters.
Dangerous goods cannot simply be placed into any convenient box, drum, jerrican or intermediate bulk container. The IMDG Code contains packaging provisions connected to the classification and properties of the dangerous goods concerned.
Packers therefore need enough knowledge to understand the packaging requirements relevant to their work and to recognise when a proposed package is unsuitable.
They also need to understand that apparently minor deviations can have consequences. Using a different type of packaging, changing a closure or exceeding a permitted quantity can affect compliance even when the product itself has not changed.
Understanding classes, UN numbers and packing groups
Function-specific knowledge begins with an understanding of how dangerous goods are identified.
The IMDG Code divides dangerous goods into nine hazard classes. Products and substances may also have subsidiary hazards, while many dangerous goods are assigned a packing group reflecting their degree of danger.
UN numbers provide internationally recognised identification for dangerous substances and articles.
Packers do not necessarily need the same depth of classification knowledge as employees whose responsibility is to classify products. They do, however, need enough knowledge to understand the information supplied to them and how it affects packaging, marking and labelling.
Recognising a Class 3 flammable liquid, a Class 8 corrosive substance or Class 9 lithium battery consignment should not simply be a matter of recognising different coloured diamonds. Employees should understand that these classifications lead to specific transport requirements.
Package marking and labelling
Correct packaging is only one stage in preparing dangerous goods for maritime transport.
Packages may require UN numbers, Proper Shipping Names, hazard labels, orientation arrows and other markings depending on the goods and packaging involved.
These labels and markings communicate essential information to everyone who subsequently handles the consignment. Warehouse personnel, freight forwarders, terminal operators, shipping lines and emergency responders may all rely on them.
Packers and cargo handling personnel therefore need to understand the importance of keeping required labels and markings visible and in good condition.
A correctly packed dangerous goods consignment can still create a compliance problem when its required identification is missing, damaged or obscured.
Overpacks and palletised dangerous goods
Warehouses frequently combine individual packages onto pallets and wrap them in plastic film. For operational purposes this is convenient, but under the IMDG Code this can create an overpack.
Employees preparing overpacks need to understand the requirements that follow.
If required markings and labels on the packages inside the overpack are no longer visible, relevant information may need to be reproduced on the outside. The overpack itself may also require appropriate identification.
This is exactly the type of detail that demonstrates why general dangerous goods awareness alone may not be sufficient for employees performing packing functions.
Function-specific IMDG training should connect the regulatory requirements directly to activities employees carry out every day.
Loading dangerous goods into containers
Container loading staff occupy another critical position in the transport chain.
Once packages have been loaded into a freight container and the doors have been closed, problems become much harder to detect. The container may travel by road to a terminal, remain in a stack and subsequently spend weeks aboard a vessel.
Loading personnel therefore provide an important final opportunity to identify problems before the cargo disappears inside the closed cargo transport unit.
Packages should be checked for obvious damage before loading. A leaking drum, damaged fibreboard box or unstable pallet should not simply be placed inside a container because the vessel’s closing time is approaching.
Container loading personnel need enough training to recognise when normal loading should stop and when the issue must be referred to a competent person.
Segregation is particularly important at sea
One of the most important subjects for dangerous goods container packing is segregation.
Different dangerous goods can react dangerously if they leak, mix or become involved in the same incident. The IMDG Code therefore establishes segregation requirements intended to keep incompatible dangerous goods sufficiently separated.
This becomes especially important when different dangerous goods are being considered for loading into the same cargo transport unit.
Container loading staff should not make assumptions based simply on whether there appears to be enough physical space between two packages. The relevant IMDG segregation provisions need to be considered.
Function-specific training should therefore give employees an understanding of segregation principles and the procedures they need to follow when determining whether dangerous goods can be packed together.
Cargo securing inside the container
Dangerous goods must remain secure throughout the transport operation.
A container can experience acceleration, braking, vibration, rolling and other movement during its journey. Poorly secured packages can move, fall, become damaged or damage neighbouring packages.
Container packing personnel therefore need to consider how the cargo will behave during transport rather than simply making everything fit inside the available space.
Heavy packages should not be positioned in a way that can crush weaker packaging. Drums, IBCs and palletised cargo need to be appropriately secured against movement.
Good container packing is therefore a combination of dangerous goods knowledge and practical cargo securing competence.
Checking the cargo transport unit
The condition of the container itself also matters.
Before loading, personnel should consider whether the cargo transport unit is suitable for the intended goods. Obvious structural damage, contamination, holes, defective doors or other significant defects can create problems during transport.
The internationally recognised CTU Code provides additional guidance for the safe packing of cargo transport units and is specifically referenced within the IMDG training framework as relevant material for function-specific training.
For container loading staff, understanding the relationship between dangerous goods requirements and correct CTU packing practices is therefore particularly valuable.
Container placarding and identification
Dangerous goods requirements do not stop at the packages inside the container.
Cargo transport units carrying dangerous goods may require placards and other marks on their exterior depending on the cargo and applicable IMDG provisions.
Personnel involved in preparing containers for transport should understand that package labels and container placards serve different purposes.
A container that has been packed correctly internally but is incorrectly placarded externally can still cause serious problems further along the transport chain.
Correct external identification enables terminals, carriers and vessel personnel to recognise the hazards associated with the cargo transport unit and apply the appropriate handling and stowage requirements.
Safety and emergency awareness
Packers and container loading staff also need safety training appropriate to the risks associated with their work.
The IMDG training framework includes subjects such as safe package handling, appropriate methods of stowage, available emergency response information, the hazards presented by dangerous goods and immediate actions following an unintended release.
This has direct practical relevance.
If a drum starts leaking while being loaded into a container, the employee needs more than theoretical knowledge of its hazard class. They need to know that normal operations should stop, how to protect themselves and how to activate the site’s incident or emergency procedure.
Companies should therefore combine IMDG training with workplace-specific instruction covering PPE, spill procedures, emergency arrangements and escalation routes.
Training before employees work independently
The IMDG Code requires shore-based personnel to receive training before assuming dangerous goods responsibilities. Personnel who have not yet received the necessary training should perform relevant functions only under the direct supervision of a trained person.
This requirement is especially relevant to warehouses and container packing facilities where new employees may quickly become involved in operational work.
Dangerous goods training should therefore be incorporated into onboarding rather than postponed until a convenient training date months later.
Training needs should also be reassessed when responsibilities change. A warehouse employee who previously only moved sealed pallets but begins independently packing dangerous goods into containers has acquired a substantially different function.
Online IMDG Code Packer training
For personnel who pack dangerous goods or load and unload cargo transport units, YourSafetyStore.co.uk offers the E-learning IMDG Code Packer Course (English).
Unlike a general IMDG Awareness course, this programme is specifically aimed at personnel who require IMDG knowledge for packing dangerous goods and those involved in cargo handling and loading or unloading cargo transport units.
The course consists of three modules. It introduces the IMO and international regulatory framework, covers general IMDG provisions, dangerous goods classes, packing groups and safety, and includes a dedicated module addressing segregation and related provisions.
The course concludes with a multiple-choice assessment. Participants achieving a score of at least 70% receive an E-learning IMDG Code Packer Course Certificate.
The current course takes approximately three hours depending on the participant and is available online, allowing personnel to complete the training without attending a conventional classroom course.
For UK businesses employing dangerous goods packers or container loading staff, this function-oriented course provides a logical training option.
Visit the IMDG / Sea Transport section of YourSafetyStore.co.uk and select the E-learning IMDG Code Packer Course (English).
Training should follow the employee’s function
An important principle of the IMDG Code is that training should be commensurate with responsibilities.
This means that an office employee requiring general awareness may not need exactly the same training as someone physically packing dangerous goods into a container. Equally, a packer may not require the same detailed training as a person responsible for classifying complex dangerous goods.
The employer should determine which employees require training, what level of knowledge their function demands and how that competence will be maintained.
Training must also be periodically supplemented with refresher training to account for changes in regulations and practice.
The last opportunity to prevent a problem
Packing and container loading are among the most important control points in the dangerous goods sea transport chain.
Once a container has been sealed and transported to the port, correcting an incorrectly packed shipment becomes much more difficult and expensive. A packaging error, incompatible combination of dangerous goods, missing label or poorly secured drum may remain hidden until the container is already deep inside the maritime logistics system.
Proper IMDG training for packers and container loading staff helps prevent these problems at their source.
Employees who understand packaging, labels, overpacks, segregation, container preparation, cargo securing and dangerous goods safety are better equipped to recognise when a shipment is ready to proceed – and, just as importantly, when it is not.
For UK businesses shipping dangerous goods internationally, investing in function-specific IMDG competence therefore supports not only regulatory compliance but also safer containers, fewer disruptions and a more reliable maritime supply chain
