USE or storage of fire-extinguishing media containing the ‘forever chemical’ perfluorooctane sulfonic acid is to be banned on ships from the start of next year.

The new restrictions form part of updates to the Safety of Life at Sea and High-Speed Craft codes agreed by the International Maritime Organization, according to loss-prevention advice from P&I club Gard.

PFOS, as it is known, is resistant to heat and is able to repel both oil and water. Historically, it was considered ideal for a wide range of industrial applications.

These included firefighting foams, particularly those used to tackle so-called Class B fires involving flammable liquids.

However, PFOS does not break down easily in the environment and can contaminate soil, surface waters, groundwater, drinking water and the food chain.

It also accumulates in living organisms over time and has been associated with serious health risks, including cancer, liver damage, cardiovascular disease and infertility.

As a result, it was classified as a persistent organic pollutant under the 2009 Stockholm Convention, and land-based fire brigades in many countries stopped using it long ago.

However, it is still permitted in certain jurisdictions and on many vessels. Furthermore, many PFOS-based firefighting foams have a long shelf life and may have been supplied to ships prior to regulatory updates.

The IMO has now acted by adopting amendments to Solas Chapter II-2 and the 1994 and 2000 High-Speed Craft codes.

These changes regulate the on board use and storage of fire-extinguishing media containing PFOS in both fixed and portable firefighting systems and equipment.

The maximum allowable concentration limit has been set at 10 mg per kg, which equates to 0.001% by weight.

New vessels constructed on or after January 1, 2026 must comply upon delivery. Existing vessels must comply no later than the first survey conducted on or after January 1, 2026.

Gard recommends that owners ensure compliance by adopting a structured compliance plan.

This should include a review of system inventories and safety certificates, in order to identify all firefighting systems and equipment that contain PFOS-based extinguishing media.

Where documentation is unavailable, this will entail sampling and testing the equipment in accordance with a recognised standard.

Non-compliant extinguishing media should be removed or replaced and delivered to appropriate shore-based reception facilities. Tanks and systems should then be thoroughly cleaned to remove any residues.

All replacement kit should be type-approved and certified in accordance with applicable IMO guidelines. Documentation to prove this point — such as the manufacturer’s declaration and laboratory test reports — should be kept.

However, a simple statement from the manufacturer proclaiming the foam PFOS-free may not be sufficient. A proper declaration should include details such as type, production period, batch number, and reference to the type approval certificate.

Compliance must then be verified by the flag state or a recognised organisation.

The presence of PFOS may be recorded in a ship’s Inventory of Hazardous Materials for Hong Kong Convention purposes. Owners should update their IHM if necessary, in line with both EU and IMO requirements.

Classification societies can advise in the case of any difficulties, Gard added.