We have received the information regarding measures to address the Revised Recommendations for Entering Enclosed Spaces Aboard Ships from ClassNK.

At the 110th session of the Maritime Safety Committee (MSC 110) held in June 2025, the Revised Recommendations for Entering Enclosed Spaces Aboard Ships were adopted as IMO Resolution MSC.581(110). This resolution invites the Assembly to revoke resolution A.1050(27) and aims to prevent fatalities and serious accidents related to enclosed space entry by clarifying requirements for definitions, risk assessment, atmosphere testing, carbon dioxide (CO2) management, and emergency preparedness.

For details of the amendments, please refer to the ClassNK Technical Information.

In light of these revised recommendations, we would like to reiterate the importance of safety measures during enclosed space entry. Most accidents are caused not by equipment failure, but by human factors such as procedural shortcuts or complacency. Based on lessons learned from past incidents, Members are advised to pay particular attention to the following points:

1. Combating "Normalisation of Deviation"

• Casualty investigations frequently reveal that unsafe practices were not isolated incidents but had become habitual. When shortcuts—such as skipping safety checks or entering without proper PPE due to time constraints—are repeated without immediate negative consequences, they gradually become accepted as standard practice (“normalisation of deviation”).
• To break this chain of invisible risk, it is essential to foster a Safety Culture where strict adherence to basic procedures is the norm and where crew members feel empowered to correct each other's unsafe behaviors.

2. Strict Implementation of Risk Assessment and Master's Verification

• Risk assessments must be conducted by the Responsible Officer or Safety Officer, and the process of verification and approval by the Master must be strictly enforced.
• The Master must make a comprehensive and holistic judgment considering weather conditions, ship motion, interference with other operations, and crew fatigue. The process of granting final permission must never be allowed to become a mere formality.

3. Permit to Work and Stop Work Authority

• The Permit to Work is not a mere checklist exercise. It represents the Master’s final verification and permission as the ultimate safety authority.
• On the other hand, Stop Work Authority is a right and duty held by every crew member, regardless of rank. Anyone who perceives an unsafe condition must halt the operation immediately. The Master must guarantee that crew members who stop work for safety reasons are supported and subject to no disadvantageous treatment. Cultivating a culture where crew members can immediately stop work when they feel unsafe is the last line of defence against accidents.

4. Rigorous Atmosphere Testing and Ventilation

• The reliability of gas detectors is a lifeline. Ensure they are calibrated according to the manufacturer’s instructions and function-tested (bump tested) immediately before every use.
• Hazardous gases can stratify at different heights depending on specific gravity. Testing only at the entrance is insufficient; samples must be drawn from the top, middle, and bottom levels of the space using extension tubes.
• Continuous ventilation should be maintained throughout the entire operation to ensure a steady supply of fresh air.

5. Preventing Secondary Casualties during Rescue Attempts

• A significant number of enclosed space fatalities involve would-be rescuers who instinctively rush in to assist a collapsed shipmate without proper breathing apparatus, only to become victims themselves.
• Crew members must be trained to resist this emotional impulse. Adhering strictly to emergency procedures and waiting for a team equipped with SCBA is the only effective way to save lives.