PFAS-Free Foam: What Thai Operators Must Test Before Specifying

With the IMO PFOS prohibition under Resolution MSC.532(107) entering into force on 1 January 2026, every Thai operator running a foam-based fire-protection system on or near the water faces the same procurement question: which PFAS-free concentrate do we standardise on, and how do we prove it works with the proportioner we already own?

This post is not a brand recommendation. It is a working testing checklist for Thai EHS managers, EPC reviewers and corporate fire-protection leads scoping a retrofit alongside a FireDos GEN III proportioner upgrade. The two AR-grade PFAS-free product families most often evaluated in Thai marine and tank-farm scoping are the VERSAGARD family from Perimeter Solutions in the United States and Williams THUNDERSTORM from Johnson Controls — both 3×3, alcohol-resistant, fluorine-free, and listed across the relevant approval stacks. The decision between them is shaped by the binding listing language, the existing proportioner, and the underwriter network — not by SATU.

SATU’s role: we scope and run the compatibility test. We do not recommend a brand. Whichever concentrate you choose, it must be proven against the proportioner before sign-off, and the listing stack must match what your underwriter and class society want to see.

The five things that must be tested before specifying

1. Proportioning-rate accuracy with the actual proportioner

NFPA 11 requires the proportioning rate to stay within the design band — typically 3% +0.3 / -0 percentage points for a 3% concentrate. AR-grade fluorine-free concentrates are usually more viscous than legacy AR-AFFF and are sometimes pseudoplastic, which means they behave differently at low flow. Until the rate is measured at full and partial flow against the installed proportioner with the candidate concentrate, the system is not commissioning-ready.

FireDos GEN III water-driven proportioners (FD2000, FD6000, FD10000, FD20000) are foam-agnostic by design and are FM Approved across a 1:15 turndown, but the seal package must be matched to the chosen concentrate, and the resulting rate must still be witnessed and logged.

2. Listing stack alignment

The binding listings vary by site. Marine and FSRU work usually requires IMO MSC.1/Circ.1312 + MED Wheelmark; tank-farm and refinery work usually requires UL 162, FM 5130, and EN 1568 Parts 3 and 4 at the 1A/1A class; aviation and helideck work requires ICAO Level B or Level C. The candidate concentrate must satisfy every listing the underwriter and class society name in the spec — not just one or two of them.

3. Design density at the discharge device

The application rate at the discharge device must meet the NFPA 11 (2024 edition) minimums for the protected hazard. For Class IB and IC hydrocarbons in fixed-roof tanks the minimum is 4.1 L/min/m² at the foam-water solution; for external floating-roof rim seals the minimum is 12.2 L/min/m² over the rim seal area. For polar-solvent service the rate is raised per the manufacturer’s listing-specific guidance. The candidate concentrate must be tested at the design density the discharge device actually delivers, not at a marketing-data-sheet number.

4. Seal-material compatibility

Older bladder-tank and balanced-pressure proportioners were sealed for AR-AFFF. AR-grade fluorine-free concentrates may degrade the existing seal package. The compatibility test must therefore include a soak-and-recheck on the actual O-rings, gaskets and diaphragms in the proportioner, with photographs and durometer readings before and after. If the existing seals fail, plan the seal-package change as part of the retrofit, not as a warranty surprise.

5. Foam-expansion and drainage behaviour at the working nozzle

Each concentrate’s foam expansion and 25% drainage time differs at the working nozzle — semi-aspirating, aspirating and system nozzles all behave differently. The crew that responds to the fire must train on the actual expansion behaviour of the concentrate that has been installed, not the one that was there last year. Capture expansion ratio and drainage time during commissioning and put both on the ITM record.

The two AR-grade families most often evaluated in Thailand

The lead grade in each family below is a 3×3 alcohol-resistant synthetic fluorine-free foam (AR-SFFF), so the proportioning hardware is common; VERSAGARD is also offered as a 1×3 volume grade, which changes the proportioner setting. The certificate packages differ.

Williams THUNDERSTORM WNF33A by Johnson Controls

Williams Fire & Hazard Control is a Johnson Controls foam brand. The AR-grade variant most often evaluated for Thai hydrocarbon and polar-solvent service is:

  • THUNDERSTORM WNF33A 3×3 — alcohol-resistant fluorine-free foam at 3% on hydrocarbons and 3% on polar solvents: UL 162 Listed; EN 1568 acetone performance IA/IA on an MPA Dresden certificate; and a UL-witnessed LASTFIRE result of GOOD across all six tests, in both fresh and salt water.

Thai operators commonly place two further Johnson Controls AR-SFFF concentrates on the same selection sheet: ANSUL NFF-331 and Chemguard NFF-331, both 3×3. Their listing packages must be read from the current Johnson Controls datasheet for the grade offered; they must not be inferred from the THUNDERSTORM certificates.

VERSAGARD family by Perimeter Solutions

The VERSAGARD line is Perimeter Solutions’ next-generation AR fluorine-free flagship, built on a long F3 history. The variants most commonly evaluated for Thai marine and tank-farm service are:

  • VERSAGARD AS-100 3×3 — alcohol-resistant fluorine-free foam, 3% on hydrocarbons / 3% on polar solvents / 1% on Class A: UL 162 Listed, IMO MSC.1/Circ.1312, EN 1568 Part 3 IA/IA and Part 4 IA/IA on fresh and sea water (Bureau Veritas certificate), ICAO Level B, LASTFIRE pass rated ACCEPTABLE/GOOD/GOOD on sea water, GreenScreen Certified.
  • VERSAGARD 1×3 — the matched volume grade to AS-100: UL 162 Listed, EN 1568 Part 3 IA on fresh water and IB on sea water.

The concentrate’s defining characteristic is no significant viscosity change in the presence of water, which protects long-term proportioner accuracy.

NFPA 11 application rates — both families

For AR-grade fluorine-free concentrates, NFPA 11 sets the design densities as follows:

  • Fixed monitor and foam-chamber service on hydrocarbon storage tanks: typically 4.1 L/min/m², with discharge time set per the tank type and hazard.
  • Polar-solvent service: design density per the NFPA 11 table for water-miscible fuels (raised over hydrocarbon rate) and listing-specific guidance from the manufacturer.
  • Sub-surface and semi-subsurface injection: rate and discharge time per the relevant NFPA 11 chapters, with supplier confirmation of compatibility.

Proportioning rate is 3% for both AR-grade products. The application rate against the specific concentrate listing letter must be confirmed on every retrofit before sizing the FireDos proportioner.

Storage and stability

VERSAGARD AS-100 is supplied in 20 L and 25 L PE prismatic containers, 200 L PE cylindrical drums and 1,000 L IBCs, with a recommended storage temperature range of 0°C to +50°C.

Container sizes, storage temperature range and shelf life for the Johnson Controls concentrates must be taken from the current datasheet for the grade quoted; no figure for them is carried here. In a Thai bund the ambient soak temperature is the figure to check first: it governs both stability and the viscosity the proportioner sees. Annual sample testing per NFPA 11 and EN 13565-2 is required for every family listed above.

Compatibility with FireDos GEN III

FireDos GEN III FD2000, FD6000, FD10000 and FD20000 proportioners are foam-agnostic by design, with the seal package selected for the specific concentrate. In Thai retrofits SATU routinely commissions FireDos with VERSAGARD AS-100 3×3 for tank farms, mixed hydrocarbon-and-polar-solvent service, jetty manifolds and FSRU duty. Where a Johnson Controls concentrate is specified instead, its seal package and measured proportioning rate must still be established before sign-off.

Mobile responses use the FireDos M-series monitors — M2 (500 to 2,500 L/min), M4 (2,000 to 8,000 L/min) and M9 (scalable across 10,000 to 40,000 L/min where the supply allows; design throw at 30° elevation; 5 m mounting height; available as fixed monitor or trailer-mounted) — with portable proportioners selected to match the chosen concentrate.

IMO 2026 marine certifications at a glance

The IMO 1 January 2026 PFOS transition under MSC.532(107) turns on the marine-side listing. What the certificates state:

  • VERSAGARD AS-100 3×3 — UL 162 Listed, IMO MSC.1/Circ.1312, EN 1568 Part 3 IA/IA and Part 4 IA/IA on fresh and sea water (Bureau Veritas), ICAO Level B, LASTFIRE ACCEPTABLE/GOOD/GOOD on sea water, GreenScreen Certified. AR-grade for hydrocarbons and polar solvents at 3%; 1% on Class A. No FM 5130 approval.
  • THUNDERSTORM WNF33A 3×3 — UL 162 Listed, EN 1568 acetone IA/IA (MPA Dresden), UL-witnessed LASTFIRE GOOD across all six tests in fresh and salt water. No FM 5130 approval. An IMO MSC.1/Circ.1312 listing is not among the certificates cited here; obtain it in writing from Johnson Controls before this concentrate goes into a marine or FSRU specification.
  • ANSUL NFF-331 and Chemguard NFF-331 — request the current certificate set, including any marine listing, from Johnson Controls for the grade offered.

For a deeper dive into the IMO 2026 transition and the supporting NFPA 11 design view, see our companion posts: IMO 2026 PFOS foam ban for Thai operators and NFPA 11 compliance for Thai refineries and tank farms. For the proportioner side of any retrofit, see the FireDos partner page and the broader SATU services portfolio.

Talk to SATU before specifying

SATU Innovative is a FireDos Authorized Distributor in Thailand and supplies SOLBERG fluorine-free foam concentrate in Thailand, including the VERSAGARD family. The Johnson Controls concentrates named above are included because Thai operators commonly evaluate them; SATU does not supply them. We provide the audit, the engineered retrofit, and the post-commissioning ITM documentation in one scope — including the proportioner-and-concentrate compatibility test that any PFAS-free retrofit must be signed off against. Request a Quote and we will return a scoped proposal within five working days.

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SATU Innovative is an authorised Thailand service partner for the brands behind this guidance.


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