POPFREE focus area: Firefighting foams
One important use for PFAS is related to firefighting foams and involves different users, e.g. the municipal Fire and Rescue Services (FRS), the petroleum and chemical industry, Airports, the military, and by the maritime and offshore sector. The most efficient foams used today are based on the use of various fluorochemicals, and are normally designated AFFF (Aqueous Film Forming Foam) or FFFP (Film Forming Fluoro Protein foams). As a result of the environmental concern related to these foams, the foam industry have developed foam concentrates without fluorochemicals (PFAS) which are normally referred to as 3F (Fluorine Free Foam). However, there is currently a great concern about the efficiency compared to existing AFFF and FFFP and there are also practical problems for the users due to very high viscosities of the foam concentrates.
- Performance level of fluorine free alternatives, for instance stability, surface tension and oleophobicity
- Practical issue in use phase, i.e. high viscosity of some fluorine free alternatives.
- Establishment of a list of requirements as a complement to existing standards identifying critical properties that is of importance for PFAS free foams.
In the project, focus will on trying to develop a PFAS-free foam that provides similar firefighting efficiency as existing AFFF and FFFP foam, but with significantly reduced viscosity of the concentrate compared to 3F formulations. New strategies described as solutions to reduce surface tension and obtain oleophobic characteristics (lower fuel pick-up in the foam/lower risk of re-ignition of the foam after extinguishing the fire/longer burn-back times of the foam) will be evaluated. Most relevant for the firefighting foams will be the natural surfactant that have been identified, the particle-stabilized foams approach and formulating foams with a deliberate, built-in, low stability towards formation of fuel-in-water emulsions (using the SAD concept and/or any commercially available surfactants with “fuelophobic”, but still hydrophobic, headgroups).
Evaluation of the new foam characteristics will be made using both non-fire-based in-house methods (present at Dafo Fomtec), small scale standardized test methods. First of all small scale standardized test methods, and (for the most promising candidates) large scale standardized fire tests will be performed.
Manufacturers of potential alternatives to PFAS and producers of firefighting foam.