A coalition of NGOs urges the IMO to reject ammonia discharge proposals, advocating for onboard retention to protect ocean health.
A coalition of environmental and technology NGOs has urged the International Maritime Organisation (IMO) to reject proposals allowing ships to discharge ammonia effluent into the ocean, reports Athens-based Safety4Sea.
The appeal followed discussions at the IMO's Pollution Prevention and Response Sub-Committee in London, where governments examined how to manage ammonia waste from ammonia-fuelled vessels. The NGOs warned that permitting discharge would swap one pollution problem for another.
Groups including Opportunity Green, Environmental Defence Fund, One Planet Port, Pacific Environment, Clean Shipping Coalition, Seas at Risk, and ZESTAs called for ships to retain ammonia effluent onboard and offload it at port reception facilities. They stated that this approach would cut greenhouse gas emissions without introducing toxic marine pollution.
Ammonia effluent is produced when leftover ammonia gas is absorbed into water during routine operations. Some Member States discussed conditional discharge if dilution standards were met, but NGOs cautioned that long-term ecosystem risks remain poorly understood.
They warned that widespread discharge could add reactive nitrogen pollution, worsening eutrophication, oxygen depletion, and ocean acidification. With up to half of ships projected to run on green ammonia in a decarbonised future, routine disposal could strain ocean health.
The NGOs urged the IMO to adopt precautionary rules prohibiting discharge at sea, requiring onboard retention and port offloading. They argued that this would support a circular economy by enabling reuse in chemical and fertiliser industries.
The coalition also called for transparent, science-based evidence to guide IMO decisions, stressing that exclusive shore disposal may not be burdensome given small effluent volumes. They asserted that real climate action must prioritise efficiency and wind propulsion, ensuring ammonia fuel adoption does not undermine ocean health.
