The LWF Blog

Fire Safety Engineering for Design – Foam Fire Suppression Systems – Part 269

January 12, 2026 11:36 am

LWF’s Fire Safety Engineering blog series is written for Architects, building designers and others in the construction industry to highlight and promote discussion on all topics around fire engineering. In part 268, LWF talked about how foam suppresses and extinguishes fire by looking at a particular type of foam – Synthetic Detergent. In part 269, we look at the composition and capabilities of film-forming fluoroprotein foams.

Film-forming fluoroprotein foam (FFFP)

A protein-based foam is known for having good stability and heat resistance, while film-forming foams tend to exhibit fast knockdown effects. Some manufacturers who wished to combine the two types of benefit developed film-forming fluoroprotein, sometimes abbreviated to FFFP. The resulting foam is one that has good all-round properties, without having quite the same knockdown as an AFFF or quite as much burn-back resistance as an FP foam.

The reasoning behind AFFF not being quite as impactful as either individual element is that a fast knockdown foam is usually rapidly-draining fluid foam and for burn-back resistance, a slow-draining stable foam excels. While AFFF is a very useful formula, it cannot absolutely fulfil both requirements to the same extent as the best-performing foam in that area.

Standard FFFPs are not suitable for use on water-soluble fuels. They are available in 3% and 6% grades with low-temperature capability. FFFPs are commonly used through medium-expansion foam making equipment and can achieve expansion up to approx. 50:1, although it is more usual in a 10:1 expansion ratio.

Alcohol Resistant Foam

Polar solvents, such as water, acetone and ethanol; and water miscible fuels, such as alcohols and ketones, are destructive to standard hydrocarbon type foams. This is due to the extraction of the water contained in them resulting in the foam blanket being destroyed rapidly.

In order to suppress fire involving polar solvents and water miscible fuels, a special multi-purpose concentrate is required, often referred to as Alcohol Resistant foam (AR). AR may have a synthetic AFFF base or an FFFP base. Either may be used successfully on hydrocarbon and polar solvent fires.

In part 270 of LWF’s series on fire engineering we will discuss Alcohol Resistant Foam in more detail, as well as touching on Class A foam.  In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients since 1986 to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact the LWF office on 0800 410 1130.

While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.