Foam concentrate testing, and what the PFOS prohibition actually requires in 2026
Foam concentrate is tested three years after it is supplied to the ship and every year after that. Since 1 January 2026 there is also a SOLAS prohibition on PFOS in extinguishing media. This note separates what is in force and enforceable at survey today from what is an EU market restriction with a later date.
The testing interval, and the exact wording
MSC.1/Circ.1312, dated 10 June 2009, covers low expansion foam concentrates. Section 5 of its annex reads: except for tests in accordance with paragraph 4.7, the first periodical control of foam concentrates should be performed not more than 3 years after being supplied to the ship, and after that, every year. The tests required by paragraph 4.7 should be performed prior to delivery to the ship and annually thereafter.
So: three years, then annually. The exception is the chemical stability test for protein-based alcohol-resistant concentrates, which runs before delivery and then annually. MSC.1/Circ.1432 repeats the three year point in its own note, and the Marshall Islands restates it in MN 2-011-14 with the addition that the tests are conducted by laboratories or authorised service suppliers acceptable to the recognised organisation.
There is a Corr.1 to MSC.1/Circ.1312. There is no Rev.1. High expansion foam goes to MSC/Circ.670 and medium expansion to MSC/Circ.798, which are separate circulars with their own requirements.
What is in the periodical control
| Paragraph | Test |
|---|---|
| 4.1 | Sedimentation |
| 4.2 | pH value |
| 4.3 | Expansion ratio |
| 4.4 | Drainage time |
| 4.5 | Volumic mass, that is density |
| 4.6 | Small scale fire test, for protein-based alcohol-resistant concentrates |
| 4.7 | Chemical stability test, for protein-based alcohol-resistant concentrates |
The tests at 4.1, 4.3 and 4.4 are carried out on samples maintained at 60 degrees Celsius for 24 hours and then cooled to the test temperature. The circular also names what causes abnormal ageing: excessive ambient storage temperature, contamination of the concentrate, and incomplete filling of the tank.
What a fail means, honestly
MSC.1/Circ.1312 sets no numeric pass or fail criteria. Section 4 says only that deviations from the values obtained during the type approval tests should be within ranges acceptable to the Administration. There is no IMO-defined pass threshold, no IMO-defined top-up allowance and no IMO-defined retest rule.
In practice the laboratory reports the measured values against the type approval values, and the decision is taken with the flag or class. Anyone showing you a neat pass and fail table with percentages is showing you a maker's or a laboratory's internal criteria, not an IMO requirement. Our report states the measured value, the type approval value and the deviation, and says plainly whether the concentrate meets the criteria of the governing requirement, so the decision is yours to take with your surveyor rather than ours to take for you.
The one place the circulars do say replace is MSC.1/Circ.1432 paragraph 7.11.4: protein-based foam concentrate in portable containers and tanks more than five years old is subjected to the MSC.1/Circ.1312 tests, or renewed. The same paragraph accepts factory-sealed non-protein containers less than 10 years old without the periodical tests, and requires the tests for any non-sealed container or where production data is not documented.
PFOS: what is in force now
Resolution MSC.532(107) amended SOLAS chapter II-2 with a new regulation II-2/10.11, and resolutions MSC.536(107) and MSC.537(107) made the matching amendment to the 1994 and 2000 HSC Codes. The prohibition entered into force on 1 January 2026.
| Point | Requirement |
|---|---|
| What is prohibited | The use or storage of fire-extinguishing media containing PFOS, in both fixed systems and portable firefighting equipment |
| Threshold | Containing PFOS means present in a concentration above 10 mg/kg, that is 0.001 per cent by weight |
| New ships | Ships constructed on or after 1 January 2026 comply at delivery |
| Existing ships | Comply not later than the first survey on or after 1 January 2026, that is the first annual, periodical or renewal survey falling due, for the Cargo Ship Safety Equipment, Cargo Ship Safety, Passenger Ship Safety or High-Speed Craft Safety Certificate |
| Evidence | The maker's declaration or laboratory test reports. The declaration should state the foam type, production period, batch number and the type approval or MED certificate reference |
| Where no declaration exists | For media installed before 1 January 2026 with no declaration and no laboratory report, sampling and testing on board to a recognised standard is required |
| Disposal | PFOS removed from a ship goes to appropriate shore-based reception facilities, and the removal and delivery are recorded in the official log book |
MSC.1/Circ.1694, approved at MSC 110 in June 2025 with effect from 1 January 2026, carries the unified interpretations. IACS UI SC309 and UI HSC11 cover the same ground.
What is not prohibited, and where the confusion comes from
The SOLAS prohibition covers PFOS. It does not cover all PFAS. IMO received proposals to replace PFOS with PFAS in these amendments and decided that a ban on fluorinated substances in foam concentrates is not necessary at this time, to be revisited if needed.
The broad PFAS restriction is European market law, not SOLAS. Commission Regulation (EU) 2025/1988, in force 23 October 2025, creates REACH Annex XVII entry 82. Its core prohibition on placing on the market and use of firefighting foams containing PFAS at or above 1 mg per litre, summed across all PFAS, applies from 23 October 2030, with earlier dates for portable fire extinguishers, for alcohol-resistant foams in portable extinguishers, and for training and testing foams. Separately, PFOA and PFHxS are already listed in Annex I of the EU POPs Regulation, and the narrow derogation for existing firefighting foam stock containing PFOA expired on 4 July 2025.
If you are planning a changeover on a European-trading fleet, ask us for the current position on the marine derogations in entry 82 before you fix a budget year. Some of the dates being quoted in the market come from press summaries rather than the operative text, and we would rather check the text with you than repeat a date we have not read ourselves.
What a compliant changeover has to include
- Draining and removal of the existing concentrate, with IBC tanks supplied and collected by us.
- Certified disposal through a licensed facility, with the disposal certificate.
- Tank and line cleaning and flushing. Residual concentration matters: the EU restriction sets a separate limit of 50 mg per litre for fluorine-free foams originating from equipment cleaned to best available techniques.
- Supply and filling of the new concentrate at the same mixing ratio, 1, 3 or 6 per cent, and a similar viscosity. A different viscosity can mean new foam pumps and a re-adjusted, re-verified mixing unit.
- Equivalent approvals: regular, alcohol-resistant or multi-purpose as applicable, with type approval under MSC/Circ.670 for high expansion or MSC.1/Circ.1312 for low expansion, and a certificate that states the absence of PFOS.
- System function test and a documentation pack for class and port state control.
Inside-air foam systems under MSC.1/Circ.1271 are a special case: only the exact foam brand, type and mixing rate listed on that system's type approval or MED certificate may be used. Substituting a nominally equivalent product invalidates the approval.
One number worth keeping
At the five-yearly service of a foam system, MSC.1/Circ.1432 requires the proportioner or mixing device to be tested to confirm the mixing ratio is within plus 30 and minus 10 per cent of the nominal ratio defined by the system approval.
Sources
Every figure above was taken from the primary document. These are the documents themselves, not summaries of them.
