Firefighting foam – evaluation, use and properties

What is meant by evaluation of firefighting foam?

Firefighting foam is evaluated in a variety of ways, but what is most crucial is its ability to extinguish a fire. Extinguishing ability is a combination of the performance of the foam concentrate and the equipment used to generate the foam. To evaluate the performance of the foam concentrate, there are standards that clearly describe how a foam concentrate should be tested. The purpose of such a standard is thus to evaluate the performance of the foam concentrate, given the same conditions in other respects. Other parameters of interest can be, for example, application rate, foam expansion ratio, drainage time and foam concentrate admixture.

With our broad expertise in the field, we can act as a partner in issues concerning systems where firefighting foam is included, both in terms of testing and evaluation. Test results can be used as a basis for decisions on, for example, the choice of suitable foam concentrate or insight into limitations.

How we test and evaluate firefighting foam

Firefighting foam is an extinguishing agent that is primarily designed to extinguish liquid fires. The performance of the foam concentrate is a crucial parameter in a fire extinguishing foam system. The performance of the foam concentrate is tested by applying a certain amount of firefighting foam, generated by a standardized foam nozzle, to a well-defined burning liquid surface. In short, you can say that the requirement is that the firefighting foam must extinguish the fire within a certain time and that the fire must not reignite within a certain time. In addition to fire tests, most standards also include testing and requirements for the physical and chemical properties of the foam concentrate. 

The knowledge of firefighting foam that exists within RISE makes it possible for us to act as discussion partners when it comes to the properties of firefighting foam. In the work of developing new foam concentrates free of highly fluorinated substances such as PFAS, RISE can contribute with tests and evaluations at different scales.

RISE tests and evaluates firefighting foam

RISE offers standard services according to the methods EN 1568, ISO 7203, IMO1312, ICAO and SP method 2580, but we can also tailor tests based on wishes. Our fire test halls offer indoor testing all year round, which means that the conditions are ideal and look the same regardless of the season. Parts of the tests are accredited according to EN ISO/IEC 17025.

RISE contributes to standardisation work in firefighting foam

RISE has been active in standardization for many years, and our experts are members of CEN/TC 191/WG3 – Fire extinguishing media - Foam concentrates. Through the standardization work, we have carried out fire tests that are currently used as a reference for evaluation of extinguishing foam. This means that RISE has been involved in the development of standards and has both the necessary equipment and experience to carry out tests and evaluate the properties of extinguishing foam. 

RISE research in firefighting foam

RISE was one of the participants in the EU project FOAMSPEX, in this project a number of experiments were carried out at different scales and with the aim of studying foam propagation and extinguishing of large cistern fires. Mathematical models were developed to describe the extent as a function of influences, including in the form of heat radiation, rheology and foam properties. The knowledge acquired in this project has later been used to advise the industry on equipment, tactics and selection of extinguishing foam.

Within the framework of the Testbed PFAS research project, a variety of PFAS-free extinguishing agents were tested. Most of the products that were tested were PFAS-free firefighting foams, but also some other liquid-based extinguishing agents were included. Some PFAS-free firefighting foams showed promising results in the fire tests that were performed, but in general the performance was lower than what would be expected from a foam concentrate with PFAS. One conclusion was that the PFAS-free foam concentrates were more dependent on the creation of a "good" foam (higher foam expansion ratio and more even bubble size distribution), i.e. that different equipment was required to generate the foam. It also turned out that the tested foam concentrates were sensitive to which fuel to extinguish, some were good at one and some were good at the other, i.e. not as "all-round" as PFAS-containing foam. The results from the evaluations of PFAS-free extinguishing agents within Testbed PFAS formed the basis for the Air Force's transition to a PFAS-free extinguishing agent in their new rescue vehicles. Link: Testbed PFAS

RISE has contributed to the purification of PFAS from water affected by firefighting foam

Practice and extinguishing with foam concentrates containing PFAS has strongly contributed to extensive contamination of PFAS substances in soil and water, from where it spreads to us humans and can affect our health in a negative way. RISE has recognised expertise in the purification of soil and water from PFAS substances as well as infrastructure for the evaluation of methods for PFAS treatment. Link: Evaluation of techniques for PFAS treatment from soil and water | RISE