When Does IMDG 43-26 Enter Into Force? Understanding the Transitional Period
The publication of a new edition of the International Maritime Dangerous Goods Code always raises practical questions for shippers, freight forwarders, packers, shipping lines and other companies involved in transporting dangerous goods by sea. With IMDG Code Amendment 43-26, one of the most important questions is straightforward: when does IMDG 43-26 actually enter into force?
The answer requires more explanation than simply giving one date. The IMDG Code operates according to a two-year amendment cycle and includes a transitional year during which the maritime dangerous goods industry can move from the existing amendment to the new one. For Amendment 43-26, that transition takes place during 2027.
The 2026 Edition incorporating Amendment 43-26 has already been published. The new provisions may be applied voluntarily from 1 January 2027, while Amendment 42-24 can continue to be used during that year. From 1 January 2028, Amendment 43-26 becomes the applicable edition and the transition from 42-24 is complete.
Understanding this timetable is essential because companies should not wait until the final mandatory date before reviewing their procedures, documentation, dangerous goods databases and employee training.
The IMDG Code follows a two-year amendment cycle
The International Maritime Dangerous Goods Code is continuously updated to reflect developments in dangerous goods transport, technology and international regulation. IMO amendments also take account of changes to the United Nations Recommendations on the Transport of Dangerous Goods, helping maintain a degree of harmonisation between maritime, road, rail and air transport requirements.
In practice, a new IMDG amendment is produced every two years.
The current sequence illustrates this clearly. Amendment 42-24 belongs to the 2024 Edition of the IMDG Code. It could be used voluntarily during 2025 and became mandatory on 1 January 2026.
Amendment 43-26 is contained in the 2026 Edition. The transition towards this edition begins on 1 January 2027, with mandatory application following on 1 January 2028.
This system provides industry with time to prepare for regulatory changes without requiring every organisation in the global maritime supply chain to change its procedures immediately when a new edition is published.
What happens on 1 January 2027?
The first date companies should place in their compliance calendar is 1 January 2027.
From this date, Amendment 43-26 can be applied during the transitional period. At the same time, Amendment 42-24 remains valid. The official IMO amendment cycle therefore identifies 2027 as a transition year during which either amendment can be valid.
This is an important distinction. It means that 1 January 2027 should not be interpreted as the date on which every shipment of dangerous goods must suddenly comply with 43-26.
Companies may continue working under Amendment 42-24 during the transition year, while organisations that are ready to move to 43-26 can begin applying the new edition.
The transitional arrangement is particularly valuable to international logistics operations. Dangerous goods shipments frequently involve manufacturers, shippers, freight forwarders, container packing facilities, terminals, carriers and receiving organisations located in different countries. Updating every procedure, database and IT system simultaneously would be difficult.
The transition year provides time for the industry to implement the new amendment in a controlled way.
Can IMDG 42-24 still be used during 2027?
Yes. This is perhaps the most important practical point about the transitional period.
During 2027, Amendment 42-24 does not suddenly become unusable simply because Amendment 43-26 is available. According to the IMO amendment cycle, 2027 is specifically designated as the year in which either amendment is valid.
A company can therefore continue applying 42-24 during the transition period while preparing its systems for 43-26.
However, organisations should manage this carefully.
The existence of two valid amendments can create confusion if employees are not sure which edition their company is applying. A dangerous goods specialist may be consulting 43-26 while a warehouse employee is still following a procedure based on 42-24. Meanwhile, a shipping system may contain information derived from another edition.
This is why transition management is as important as knowing the regulatory dates.
Companies should clearly establish which amendment they are using and ensure that classification procedures, dangerous goods databases, documentation systems and operational instructions are aligned with that decision.
What changes on 1 January 2028?
The second critical date is 1 January 2028.
The transition period ends and Amendment 43-26 becomes the applicable IMDG amendment. From that point, companies can no longer rely on the previous amendment simply because their internal procedures have not yet been updated.
For compliance managers, dangerous goods safety professionals and logistics organisations, 1 January 2028 should therefore be treated as the final implementation deadline rather than the date on which preparation begins.
Waiting until late 2027 creates unnecessary risk.
Changes to the IMDG Code can affect the Dangerous Goods List, UN entries, special provisions, packing instructions, classification requirements, documentation, segregation and operational procedures. Amendment 43-26 also contains important developments concerning batteries and vehicles, areas that are becoming increasingly significant in maritime transport.
Organisations should determine which of these changes affect their operations well before mandatory implementation.
Why use the 2027 transitional period?
The most effective approach is to use 2027 as an implementation year rather than simply regarding it as an additional year in which 42-24 can still be used.
A company can begin by identifying the dangerous goods it regularly ships and comparing relevant requirements under Amendments 42-24 and 43-26. Particular attention should be given to new or amended UN entries, special provisions and products involving batteries, battery systems and electric vehicles.
Documentation templates should also be reviewed. Dangerous goods declarations, internal checklists, booking systems and shipping software may contain references or validation rules connected to a specific edition of the IMDG Code.
The same applies to packaging and operational instructions.
A regulatory change that appears minor when reading the Code may have consequences for employees who classify products, select packaging, apply marks and labels, prepare documentation or pack cargo transport units.
The transition period provides an opportunity to identify these consequences before the new requirements become mandatory.
Training should be part of the transition plan
The move from 42-24 to 43-26 is not only a matter for dangerous goods databases and compliance manuals. Employees need to understand the requirements that apply to the functions they perform.
The IMDG Code contains training provisions for shore-based personnel involved in the transport of dangerous goods by sea. The appropriate level of training depends on the employee’s responsibilities.
Personnel involved in classifying dangerous goods require different knowledge from employees who prepare documentation, pack dangerous goods, mark and label packages, load cargo transport units or arrange maritime transport.
When an amendment changes requirements relevant to these functions, the organisation should determine whether training material and employee knowledge also need to be updated.
This is another reason why the 2027 transitional period is valuable. Instead of attempting to update all personnel immediately before 1 January 2028, companies can review their training programme during 2027 and introduce updated information systematically.
A practical timeline for IMDG 43-26
For organisations planning the transition, the timeline can be kept relatively simple.
2026: Amendment 42-24 is the mandatory IMDG Code. The 2026 Edition incorporating Amendment 43-26 has been published, allowing companies to begin reviewing the changes.
1 January 2027: The transitional period begins. Amendment 43-26 may be applied, while Amendment 42-24 remains valid.
Throughout 2027: Companies should compare the amendments, update procedures and systems, review products and UN entries, assess packaging and documentation requirements and update employee training where necessary.
1 January 2028: Amendment 43-26 becomes the applicable edition and the transition period ends.
For larger organisations, the best approach is often to establish an internal target date before the end of 2027. This provides time to identify and correct problems before mandatory implementation.
Prepare your employees for IMDG 43-26
Regulatory compliance depends not only on having access to the latest edition of the IMDG Code, but also on employees understanding how dangerous goods requirements apply to their work.
IMDG-course.com provides online training for personnel involved in maritime dangerous goods operations. The IMDG Awareness Training provides employees with a practical introduction to the IMDG Code, dangerous goods classes, identification, marking and labelling, documentation and the responsibilities associated with transporting dangerous goods by sea.
Companies preparing for the transition to Amendment 43-26 can use the transitional period to review training records and ensure that relevant personnel have appropriate and up-to-date knowledge.
Prepare your personnel for the changing IMDG requirements and view the IMDG Awareness Training available through IMDG-course.com.
Do not wait until January 2028
The key message surrounding the entry into force of IMDG 43-26 is that there is a difference between publication, voluntary application and mandatory application.
The 2026 Edition containing Amendment 43-26 is already available. The transition period starts on 1 January 2027, when 43-26 can be applied while 42-24 remains valid. On 1 January 2028, the transition is complete and Amendment 43-26 becomes the applicable edition.
For companies transporting dangerous goods by sea, 2027 should therefore be treated as a preparation and implementation year.
Organisations that review their dangerous goods portfolio, procedures, documentation, software and employee training early will have sufficient time to deal with the changes systematically. Those that wait until the end of 2027 risk having to update multiple parts of their dangerous goods management system at the same time.
The IMDG transitional period exists to make that change manageable. Using it effectively is the best way to ensure a smooth transition from Amendment 42-24 to Amendment 43-26.
