Enclosed space entry: hidden danger looms below  

Safety is paramount when entering cargo spaces, fuel tanks, ballast tanks, cofferdams, pump rooms and other similar spaces aboard ship. Without proper safety precautions and ventilation, seafarers and shoreside personnel conducting maintenance and inspection can risk serious injury and death from asphyxiation from low levels of oxygen, invisible toxic fumes, or flammable gases. Conditions in these confined spaces are hampered by poor visibility, limited access, wet ladders, and slippery surfaces, increasing the risk of falling injuries.

Despite existing regulations outlining safety procedures, enclosed space entry incidents continue to be a leading cause of seafarer fatalities. In January 2025, InterManager estimated that some 350 seafarers and third-party workers died from asphyxiation in enclosed spaces since 1996. Of these, 43 incidents had occurred since 2022, accounting for 70 deaths —20% of the total. Even more troubling, 14 of those enclosed space entry incidents occurred in 2023 alone, accounting for 34 fatalities.

Bulk carriers (nearly 35%) and tankers (over 25%) accounted for roughly 60% of enclosed space entry accidents from 1999 to 1 July 2026.

Data reported by the International Bulk Terminals Association (IBTA) was even more sobering. It reported that at least 1,100 crew and shore-side personnel died in enclosed space incidents from 2000 to 2024. Crew accounted for 700 of the fatalities (69%), with shore workers accounting for the remaining 310 deaths (31%).

The IMO, supported by InterManager and other shipping industry groups, tackled the issue with revised rules on enclosed space entry, which took effect in 2025. IMO’s tightened rules, Resolution MSC.581(110), entered into force on 3 December 2025, following their adoption by the Maritime Safety Committee at its 110th Session (MSC 110) on 27 June 2025. The new rules revoke Resolution A. 1050(27), adopted 14 years earlier by the IMO on 30 November 2011.

Class society Lloyd’s Register points out that the new IMO rules clarify the responsibilities for crew safety and training, reinforce the use of portable gas detection equipment, update enclosed-space rescue procedures, and require a ship-specific enclosed-spaces register to be maintained on board.

Editor’s note: A high-powered panel will take a deep dive into the intent and requirements of Resolution MSC.581(110) during a free, hour-long webinar, Before the Hatch Opens: What IMO MSC.581(110) Now Demands of Your Fleet and How MSA Delivers It, on 27 August 2026. To find out more about the webinar and register, please visit this link.