NGOs urge IMO: “Dilution is not a solution” – choose onboard retention & port offload for ammonia ship waste in International Shipping News 14/02/2026 Opportunity Green, Environmental Defense Fund, One Planet Port, Pacific Environment, Clean Shipping Coalition, Seas at Risk, and ZESTAs call for a precautionary approach to managing toxic ammonia effluent from ammonia-fueled ships 13 February 2026 (London, UK) – A group of environmental and technology NGOs is urging the International Maritime Organization (IMO) to reject emerging proposals that would allow ships to routinely discharge ammonia at sea. Instead, the group is calling for a simpler safeguard: retain ammonia effluent onboard and offload it at port reception facilities–so shipping can cut pollution without adding a new source of toxic marine pollution. The statement follows a week of discussions at the IMO’s Pollution Prevention and Response (PPR) Sub-Committee in London (9–13 February), where governments, for the first time, considered approaches to managing ammonia effluent generated from ammonia-fueled ships. “Shipping needs to decarbonize fast, and green ammonia could play an important role,” said Dr James Kershaw, Scientific Officer at Opportunity Green. “But we must not reduce climate pollution while normalizing ocean discharge of toxic waste. The IMO must ensure green fuels are adopted with safeguards that protect marine ecosystems, coastal communities, and seafarers.” What is ammonia effluent — and why it matters Ammonia gas is extremely toxic and harmful to human health. On ammonia-fueled ships, leftover ammonia gas (for example, when crews purge fuel lines during routine operations) must be captured and contained, often by absorbing it into water. This produces a high-strength liquid waste known as ammonia effluent. At PPR this week, some Member States discussed a framework that would allow conditional discharge of ammonia effluent into the ocean if certain operational and dilution conditions are met. NGOs warn: focusing only on short-term toxicity misses bigger risks Supporters of discharge argue that sufficient dilution can avoid immediate harmful effects on marine life. But the group cautions that’s only one part of the environmental risk: Chronic, long-term impacts from repeated low-level exposure are an evidence gap that short-duration studies cannot resolve, and more research is urgently needed. Discharging ammonia introduces reactive nitrogen pollution to marine environments, contributing to eutrophication, oxygen depletion, and ocean acidification—pressures already straining ocean health. In a fully decarbonized maritime future, 35–50% of ships are projected to run on green ammonia. If tens of thousands of vessels are periodically discharging ammonia waste, “conditional discharge” could quickly become routine, with consequences that are still unknown for long-term ocean health. “The nitrogen cycle is already beyond safe planetary boundaries—we cannot afford to normalize another source of reactive nitrogen pollution as shipping decarbonizes. The industry has an opportunity to get ammonia fuel right from the start by retaining waste onboard and landing it ashore, rather than defaulting to ocean discharge. This isn’t just about toxicity—it’s about preventing further disruption to a critical planetary system that’s already under stress,” said Dr Lucy Gilliam, Co-executive Director of One Planet Port. The alternative: retain onboard, offload in port, and enable reus