Revised IMO recommendations for entering enclosed spaces aboard ships
Enclosed space entry remains a safety challenge in ship operations and for seafarers’ working conditions. On 27 June 2025, the IMO adopted revised recommendations for entering enclosed spaces aboard ships, to be handled in accordance with the SMS systematics. This statutory news summarizes this topic.
Information for: Suppliers, manufacturers, owners/managers, and flag states.
Why updated recommendations
The industry continues to experience loss of life resulting from personnel entering shipboard spaces in which the atmosphere is unable to support life, owing to oxygen depletion, oxygen enrichment, toxicity or flammability. Consequently, the IMO has adopted revised recommendations for entering enclosed spaces aboard ships, IMO Resolution 581(110).
Investigations into enclosed space accidents consistently show that many incidents stem from a failure to systematically identify the hazards, assess associated risks and apply appropriate entry procedures. In addition, the complex structure of certain shipboard spaces can hinder effective ventilation, lighting and safe movement. Organizational leadership, both on board and ashore, is essential to ensure this guidance is properly implemented, as well as empowering shipboard personnel to make sound, safety-focused decisions.
The findings by the IMO are supported by InterManager, which, in 2025, estimated that around 350 seafarers and third-party workers had died from asphyxiation in enclosed spaces on board ships since 1996, with 43 accidents since 2022 accounting for 70 of these deaths.
Key recommendations
Due to ongoing challenges, the IMO has revised its recommendations for entering enclosed spaces aboard ships. The key takeaways:
- A safety strategy should be adopted to prevent accidents on entry into enclosed spaces in a comprehensive manner by the company, in consultation with the ship’s crew.
- This should include an Enclosed Space Register, to be produced on a ship-by-ship basis identifying enclosed spaces, the hazards of those spaces, an assessment of risks under the differing conditions likely to arise in the space, and the risk mitigation measures required to be put into place prior to entry.
- The company should elaborate a procedural implementation scheme which provides comprehensive training in the maintenance, calibration and use of atmospheric testing equipment in such spaces.
- To focus on the people, knowing that commitment, competence, attitudes and motivation of individuals at all levels determine the effectiveness of safety management measures and the safety management systems.
New guidance for gas levels and gas meters has been set, but it should be noted that the minimum required gases for the portable gas meters are stated within SOLAS Regulation XI1/7, and any additional measures including gas meters should be based on risk assessments. Such an assessment should also include the cargo that the vessel carries and the conventions that governs them: the Safety Data Sheets (SDS), the IMDG Code, IMSBC Code, International Bulk Chemical Code (IBC Code) and IGC Code to name a few.
Recommendations
DNV recommends that its customers use the new IMO circular as basis for the further development of their safety management systems and for providing vessels with the necessary information, equipment and training as prescribed by MSC.581(110). Customers should review the circular, update the SMS and focus on the implementation of safeguards, particularly with regards to:
- Handle enclosed space entry as a key shipboard operation essential to personnel safety
- Provide adequate training in the safety management of enclosed spaces
- Provide adequate time for planning enclosed space entry to ensure needed measures are followed
- Ensure the necessary safety equipment is available
- Have management of enclosed space entry on the agenda of internal audits and master’s and management reviews
