From AFFF to F3 : F3 comes to light — Part 6
Previous articles (Parts 1 to 5) have dealt with the history, chemistry, environmental and health impacts and regulations of Firefighting foams.
Introduction
From 3M’s phasing-out of fluorochemicals industry in 2000 to actual market, an ever-growing number of manufacturers have been introducing fluorine-free firefighting foams. If today, a manufacturer says that F3 are evidence and mandatory, It has not been like that in the early years after 2000.
The first years 2000-2012
In fact, during more than 12 years, only two chemists – namely Ted Schaeffer and Thierry Bluteau – were actively working to offer the first generation of F3, respectively Re-Healing Foam (Solberg) and ECOPOL(Bio-ex) These first F3 were relatively good on solvent fires but showed some weaknesses when applied on hydrocarbon fuels.
At the same time, a commercial battle was raging on between these two companies and the rest of the industry – grouped under the FFFC banner – to maintain or not the AFFF technology on the market. Despite all these efforts to undermine the F3 technology, the wind of change started to blow and several customers decided to change to an eco-friendly efficient foam.
The last years 2013-2023
This period can be considered as a transition time, when it became evidence that F3 would become in a short time the firefighting foam for the future and AFFF become a product from the past. This period brought awareness in both the customers and the manufacturers and in a few years appeared the second generation of F3. The main difference was about the fire performance on hydrocarbon fires, as it claimed the top rating under EN1568-3 and UL162. In the same time, the early chemists changed their position: Thierry Bluteau moved to work with 3FFF LTD and Ted Schaeffer retired.
Today one can find on the market at least 8-10 F3 foams, with variable performance. Most of the manufacturers are based in Europe and USA.
The level of performance has been brought to the highest level of the EN1568-3 and 4 standard and matches the expected performance for AFFF type foams.
The F3 technology
The chemist had to face a problem form the start: the removal of fluorinated compound from the original formulation meant that he would need a chemical compound/blend to offer and balance the same properties, to say the resistance to heat and fuel contamination.
We have seen in previous articles that synthetic foam formulation is a combination of surfactants, hydrophilic solvents and polymers. The choice is still wide for the chemist.
More than 7000 surfactants are listed and identified.
For the hydrophilic solvents, we can account between 800 and 1000 different molecules.
And for the polymers, it is again a wide choice, probably more than 1000 polymer types exist, without counting the numerous copolymers and the variations in polymer length and ramification degree.
We can then measure the difficulty for the chemist to select among a large choice of chemicals to combine and obtain the final product.
A suitable formulation for a firefighting foam, is the balance between the different components to achieve the desire level of extinction, while maintaining acceptable physical parameters, such as density, pH, viscosity, foam expansion, drainage time and stability over ageing.
To make a story short, the actual F3 are relying on a combination of surfactants and natural polymers to achieve an acceptable level of extinction.
Unfortunately, the use of an excessive quantity of polymers results in a dramatic increase of viscosity, making some foams almost impossible to be inducted with common dosing systems. Some dosing systems manufacturers had to modify their injection system to cope with this high viscosity; and in some case, some foams are just impossible to use on a practical point of view.
We have seen that, even if the best performing foam F3 can challenge the performance of AFFF, they are very viscous and need a specific – and expensive -dosing system to be used. That can result in a significant side cost which finally would impact on the global costs of the fire protection equipment.
Aside from the viscosity, most of these F3 contain a high quantity of solvents – mainly glycol and glycol ethers – with potential toxic effects. Most of these solvents can migrate through the skin and provoke allergy, skin sensitivity/irritation, and other health effects.
The F3 third generation
3F company dedicated itself since the start to produce F3s designed to fit perfectly to customer needs. Since this philosophy has always been in its DNA, 3F offers a full line of F3 – known as FREEGEN – to address all the potential request from the industry.
That is why 3F developed an exclusive know-how in foams and offers SMART FOAM ® : this technology allows the complete removal of solvents from the formulation. On top of that, 3F developed a special combination to control the viscosity of the product while maintaining a high level of performance on fire. As a result, 3F offers 2 SMART FOAM FREEGEN SF-LV and FREEGEN ULTRA. FREEGEN SF-LV can be inducted with any proportioning system on the market – including simple Venturi.
CONCLUSION
F3 technology has been proven efficient and easily available. With the support of EU regulation, the industry is already moving and replacing their old stock of AFFFs with F3s. F3 are continuously developed to offer to end-users more choice in concentration of use and performance. At the moment of making a choice, the fire chief must check that the foam complies with his needs and equipment, and meets the requirement he is looking for (LastFire, VDS, EN, ICAO,…)
