M51+
Fluorine-free wetting and foaming agent for Class A and B fires – one concentrate for structural, vehicle, forest and hydrocarbon fires.
M51+ from Eau&Feu, part of the AISG group, is a superior-quality fluorine-free (F3) Class A and B foam concentrate for extinguishing and securing fires involving solid materials and flammable hydrocarbon liquids. Non-fluorinated surfactants combine with a foaming base to produce a vapour-sealing foam blanket for fast control and extinguishment. Used at low concentrations as a wetting agent or as a foam, it is widely used by municipal fire services. Hexfire supplies M51+ across Central & Eastern Europe.
At a glance
Why M51+
Most incidents municipal fire brigades attend involve Class A materials – buildings, vehicles, vegetation, straw or tyres – often together with spilled fuel. M51+ covers both: as a wetting agent it helps water soak into burning material and cool it faster, and as a foam it seals hydrocarbon fuels such as petrol, diesel, crude oil and aviation kerosene.
Because it works at very low concentrations, one tank on the vehicle lasts for many interventions, which reduces stocks and logistics. M51+ contains no fluorinated surfactants and no PFAS, and it is readily biodegradable.
For alcohols and other polar solvents, choose an alcohol-resistant concentrate such as Respondol® ATF 3x3%.
How M51+ is used
| Application | Concentration | Typical equipment |
|---|---|---|
| Wetting agent – Class A fires: vegetation, forest, wood, straw, tyres, dwellings | from 0.1% (typically 0.1–0.6%) | Hose reels, water branchpipes, CAFS, vehicle proportioning systems |
| Low-expansion foam – hydrocarbon spills and fires, vehicle fires | 1% (up to 3%) | Foam branchpipes – e.g. HI-COMBAT™ LEX |
| Medium-expansion foam – spill fires, vapour suppression | 1% (up to 3%) | Medium-expansion branchpipes – e.g. HI-COMBAT™ MEX |
| High-expansion foam – flooding of cellars and enclosed spaces | 1% (up to 3%) | High-expansion generators – e.g. HI-COMBAT™ Mini Turbex |
Typical foam expansion at 3%: low expansion ≥ 10:1, medium expansion ≥ 80:1, high expansion ≥ 1080:1. For portable use, M51+ can be proportioned with HI-COMBAT™ Portable Foam Uniductors set to 1% or 3%.
Where M51+ is used
Municipal fire brigades – structural fires, car accidents and everyday Class A incidents.
Forest and vegetation fires – wetting agent for faster penetration and cooling.
Hydrocarbon risks – sites where crude oil, petrol, diesel or aviation kerosene are stored, processed or transported.
Agriculture and industry – straw, wood, textiles, tyres and mixed Class A materials.
Approvals
| Standard | Result |
|---|---|
| EN 1568-1 (medium expansion) | Approved – tested by CEREN |
| EN 1568-2 (high expansion) | Approved – tested by CEREN |
| EN 1568-3 (low expansion, heptane) | Class 3B at 1% |
| Test laboratory | CEREN, accredited to EN ISO/IEC 17025 |
Key technical data
| Property | Value |
|---|---|
| Type | Fluorine-free wetting and foaming agent for Class A and B fires (FFF / F3) |
| Use as wetting agent | from 0.1% |
| Use as foaming agent | 1% (up to 3%) |
| Appearance | Yellow liquid |
| Specific gravity | 1.02–1.04 kg/l |
| pH (20 °C) | 6–8 |
| Viscosity (20 °C) | 6–10 mm²/s |
| Surface tension (0.6%) | 24–26 mN/m |
| Freezing point | −15 °C (MPA Dresden, EN 1568:2008) |
| Storage | Max. 60 °C (intermittent); protect from sunlight and frost |
| Biodegradability | Readily biodegradable – 100% in 28 days (OECD 301 A) |
| Packaging | 20 l and 25 l cans, 200 l drums, 1,000 l IBC |
Like all foam concentrates, M51+ must be handled with eye and skin protection. See the safety data sheet, which we provide with every quotation.
Ordering
Related products
Respondol® ATF 3x3% – alcohol-resistant fluorine-free foam for hydrocarbons and polar solvents.
JetFoam ICAO-B – fluorine-free foam for airports, ICAO Level B.
HI-COMBAT™ Portable Foam Uniductors – portable inductors with 1% and 3% settings.
HI-COMBAT™ Mini Turbex – compact high-expansion foam generator.
Frequently asked questions
Is M51+ for Class A or Class B fires?
Both. As a wetting agent it is used on Class A materials, and as a foam it extinguishes and secures hydrocarbon fires. It is approved to EN 1568 parts 1, 2 and 3.
Can it be used on alcohols and polar solvents?
No – M51+ is not alcohol-resistant. For polar solvents use Respondol® ATF 3x3%.
What concentration should we use?
From 0.1% (typically up to 0.6%) as a wetting agent and 1% as a foaming agent; up to 3% where a richer foam is needed.
Can it be stored outdoors in winter?
Its freezing point is −15 °C, and a liquid core remains in the packaging even at −20 °C. Protect it from frost and direct sunlight.
Backed by expertise across the region
As the AISG group's partner for Central and Eastern Europe, Hexfire helps you choose the right fluorine-free concentrate and equipment for your risks – from the first enquiry to delivery and training.