The IMO 2026 Deadline Is Coming – Are Ships Ready?
In January 2026, the International Maritime Organization (IMO) will prohibit the use of firefighting foams containing Perfluorooctanesulfonic acid (PFOS) aboard ships.
It sounds simple, another environmental measure, one more line in the compliance checklist. Those who ever had to use the foam system in a real emergency know that it isn’t just a regulatory topic, it’s a matter of survival.
The coming ban forces the maritime industry to reconcile two imperatives – protecting the environment and protecting the ship. Whether the balance is right, and whether the alternatives truly measure up, are questions worth asking before the calendar turns to 2026.
What PFOS Actually Is and Why It Was So Effective
PFOS belongs to a family of synthetic fluorinated compounds known as per- and polyfluoroalkyl substances (PFAS). These chemicals were engineered for one primary reason, they repel oil, water, and heat like few others.
In firefighting foam, PFOS was a key component of Aqueous Film Forming Foams (AFFF) and Film-Forming Fluoroprotein Foams (FFFP) both widely used at sea. When mixed with water and air under pressure, these foams form a thin aqueous film that spreads rapidly over hydrocarbon fuel surfaces, cutting off the oxygen supply and cooling the fire simultaneously.
Here’s why it mattered on board-
- Rapid spread: The PFOS-based film moves across the fuel faster than non-fluorinated foams.
- Fuel resistance: The fluorinated layer prevents fuel re-ignition essential in Class B fires involving oil, fuel, or lubricants.
- Saltwater tolerance: PFOS foams remained stable in saline conditions, an absolute requirement for marine systems.
It’s this trifecta, the speed, sealing and stability that made PFOS the backbone of marine fire suppression systems for decades.
Why It’s Being Banned
Unfortunately, PFOS’s chemical strength is also its greatest problem. It is non-biodegradable, bioaccumulative, and persistent in soil, water, and living tissue. Once released into the marine environment through testing, maintenance, or discharge PFOS can remain for decades.
Under the Stockholm Convention on Persistent Organic Pollutants (2009), PFOS was listed among chemicals to be phased out globally. The IMO’s decision aligns maritime fire safety with that international framework.
From a regulatory standpoint, the logic is sound, the chemical’s environmental cost outweighs its benefits. But from a shipboard standpoint, it’s not that straightforward. The science is clear, but the sea doesn’t read circulars. What survives on paper often struggles in practice.
How Firefighting Foam Systems Work on Ships
Most seagoing vessels use one of the following for flammable liquid fires (Class B).
- Low-expansion foam (deck & some machinery applications): Used primarily on open deck (cargo deck/manifolds/helidecks) via monitors/applicators. IMO cap: ≤ 12:1 expansion. Design and supply remain sized at 12:1 even if the produced foam is just above that.
- High-expansion foam (machinery spaces total flooding): Generator systems that fill the space quickly (≥ 1 m depth/min), with expansion of 1,000:1 and total foam volume ≥ 5× the largest protected space.
- Medium-expansion on deck (optional case): If chosen for deck systems, 21:1–200:1 applies, and the Administration must agree to rates/capacity.
They rely on fixed tanks connected to a foam proportioner and mixing unit, with distribution through fixed nozzles or manually directed hoses. The foam’s effectiveness depends heavily on its chemistry ie. viscosity, film stability, expansion rate, and fuel repellency all of which PFOS enhanced.
IMO requires foam to be assessed with both freshwater and seawater. Real ships use seawater mostly, and some concentrates show reduced performance grades in seawater compared to potable water.
Portable and Semi-Portable Foam Units
Apart from the fixed foam systems, ships also carry portable and semi-portable foam extinguishers, typically 9 L or 20 L portable units and 45 L wheeled sets. These are required in machinery spaces, pump rooms, and near fuel manifolds under SOLAS II-2/10.
Many of these units also use AFFF or FFFP foam concentrates, and therefore may contain PFOS or related PFAS compounds. The same 2026 ban applies, after the cut-off date, even small extinguishers must use PFOS-free foam or be replaced with certified alternatives.
The change might seem minor, but it carries two practical concerns:
- Storage life: foam concentrates in small extinguishers degrade faster under engine-room heat, so testing or replacement will be needed sooner than for bulk tanks.
- Compatibility: not all new F3 foams perform identically in handheld or portable nozzles, the expansion and flow rates differ. Before refilling or replacing these units, ensure the manufacturer certifies the charge for that specific extinguisher type.
In short, the smaller extinguishers are subject to the same regulation and may actually be the first items replaced during inspection or drydock.
The Problem with Alternatives- Are Fluorine-Free Foams Ready?
The replacements being promoted today are Fluorine-Free Foams (F3) or Synthetic Alcohol-Resistant Foams (AR-AFFF without PFAS). They are often marketed as environmentally safe and compliant with IMO and SOLAS requirements.
But are they equally effective at sea? Not always.
Operational realities:
No fluorinated film: Flourine Free Foam aka F3 foams don’t form the slick, fuel-sealing film that gave AFFF and FFFP their edge. They work by building a thicker physical blanket, one that must stay intact under vibration, heat, and movement. At sea, that’s not always easy.
Burnback sensitivity: Early F3 formulations drained faster and lost their protection sooner. The latest types have improved, and when mixed and applied correctly ,right nozzle, right rate they can meet EN 1568 standards. But margin for error is smaller than before.
System compatibility: Rheology ie. the flow characteristics will be different. Not every proportioner or inductor handles F3 the same way. The thicker concentrates can upset flow balance and create weak foam. If you’re switching over, run a proper proportioning or acceptance test after changeover, don’t assume it will behave like the old batch.
Wind and throw loss: Laboratory tests are done behind screens at less than 3 m/s wind, that’s nothing more than a light puff at sea. Out on deck, real wind eats distance and tears up the foam blanket, you may need higher application rates or adjusted nozzle elevation to achieve full, even coverage.
Marine validation: Many F3s now carry IMO approval, but results still vary with seawater. Some lose expansion or drain faster than they do with freshwater.
On calm seas, all foams look equal. It’s only in chaos that the difference becomes obvious.
Testing and Certification- What the Regulation Really Requires
From 1 January 2026, every vessel must prove its firefighting foam is PFOS-free. This can be done through:
- A manufacturer’s declaration stating the product contains no PFOS; or
- Laboratory analysis of foam samples confirming PFOS content below detection limits.
In practice, the second option may be necessary if documentation is unclear or the foam’s age predates current labeling requirements.
Testing is specialized. Laboratories use analytical methods well beyond what most of us at sea ever need to understand, but precise enough to detect even trace levels of PFOS. The process can take several weeks and costs vary by region, typically USD 300–500 per sample.
What This Means on Board
For masters and chief engineers, the responsibility is straightforward. During inspections after 2026, surveyors and Port State Control officers will request PFOS-free documentation. Failure to produce it could lead to:
- Deficiency reports under SOLAS II-2,
- Possible detention, or
- Requirement to replace foam before next voyage.
Operationally, replacing foam is not trivial. Tanks must be drained, flushed, cleaned, and refilled, often involving enclosed-space work, disposal coordination, and system testing.
Planning is essential- schedule replacement alongside drydock or class renewal surveys, not after the deadline.
Looking Ahead: Environmental Progress vs. Operational Reliability
No mariner disputes the need to protect the oceans. The current IMO test window also does not model wind above 3 m/s, so shipboard acceptance tests should simulate realistic deck conditions as closely as possible.
PFOS is indeed harmful, and eliminating it aligns with broader environmental goals. But we must also acknowledge a hard truth, bluntly put environmental compliance cannot come at the cost of fire safety.
A firefighting system is not a paper exercise. It must perform, under heat, smoke, and pressure. While the new foams show promise, the maritime industry must ensure that-
- Replacement products are tested specifically for marine applications.
- Foam proportioning and distribution systems are recalibrated accordingly.
- Crew are retrained in handling and application techniques for the new formulations.
Until then, caution should guide the transition.
Necessary, Yes – But Not Simple
The IMO 2026 PFOS ban is in principle the right move for the environment. But on ships, it represents another layer of complexity in an already demanding safety regime.
PFOS earned its place through performance, and replacing it will take more than regulation, it will require practical timelines and verified testing before ships can transition with confidence.
I believe compliance should be more about confidence than paper work and certification. When the alarm sounds, the system must respond immediately and reliably every time.
This article draws on independent research and fact-checking carried out after the IMO circular on PFOS. Every effort has been made to ensure accuracy and practical relevance for shipboard application.
References and Sources
- IMO MEPC.380(81) – Amendments to the International Convention on the Control of Harmful Anti-Fouling Systems on Ships, 2001 (Adoption of controls on PFOS and PFOS-related substances), adopted 22 March 2023, entry into force 1 January 2026.
- IMO MSC.1/Circ.1312 – Revised Guidelines for the Approval of Foam Concentrates for Fixed Fire-Extinguishing Systems (Low-Expansion).
- IMO MSC/Circ.670 – Guidelines for the Approval of High-Expansion Foam Concentrates for Fixed Fire-Extinguishing Systems.
- IMO FSS Code, Chapters 6 and 14 – Fire Safety Systems Requirements for Foam Systems.
- Stockholm Convention on Persistent Organic Pollutants (2009) – Annex B (PFOS Listing).
- EN 1568: Parts 3 & 4 – European Standards for Foam Performance on Hydrocarbon and Polar-Solvent Fires.
- NFPA 11 (2021 Edition) – Standard for Low-, Medium-, and High-Expansion Foam.
- LASTFIRE Project Reports (JOIFF, 2018–2022) – Large-Scale Foam Performance Research.
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