Transitioning to Environmentally Responsible Firefighting Foams at Airports in the MENA Region
Outside the POG Industry in the MENA region, one of the largest users of firefighting foam is the aviation sector. At airports, we typically see firefighting foams deployed in a number of applications such as:
- Fire & Rescue Services (ARFF)
- Hangars
- Fuel Storage
With each of the above applications, we see different design (usage) standards applied, and each application presents its own challenges when transitioning from PFAS-containing foam agents. In this article, we will look closer at the Fire & Rescue Services and the issues facing them as they transition to a Fluorine Free Foam for the ARFF mission.
Fire & Rescue Services (ARFF)
Arguably (outside of the USA), this is one application where SFFF’s have replaced AFFF’s and FFFP’s without a deadline imposed by legislation on the use of the PFAS-containing foam agents. Air Services in Australia, Heathrow, Copenhagen, and Dubai transitioned to using SFFF during periods when they still could have used C6-based foam concentrates and, in some cases, even C8-based foam concentrates. However, each chose to move to SFFF for the ARFF mission.
DOC 9137 – AN/898 of the Airport Services Manual Part 1 – Rescue and Fire Fighting – Fourth Edition (2015) covers all aspects of the ARFF mission for those airports outside the USA, including classification of the airport based on the largest aircraft expected to use the airport. Under ICAO, aerodrome classification runs from 1 to 10, where regional airports such as Dubai International, Al Maktoum International, Abu Dhabi, Doha, Kuwait, and Jeddah are all classified as Category 10 as they all handle the Airbus A380-800.
Firefighting foams used in the ARFF mission are classified as having Performance Level A, B, or C, achieved through a test protocol that fixes the nozzle (Uni 86) and flow rate but varies the size of the pan so that the application density for testing decreases from Level A (4.1 lpm/m²) through Level B (2.5 lpm/m²) to Level C (1.75 lpm/m²). The classification of the aerodrome and the performance level of the firefighting foam dictate the minimum usable amounts of extinguishing agents required by the Airport F&RS.
The ICAO Performance Level testing makes no differentiation between PFAS-containing and fluorine-free foams, so the transition to fluorine-free foam for the ARFF vehicles in fire performance terms should create no concerns. There are two main considerations relating to performance that need to be considered:
Aspirated vs. Non-Aspirated Discharge Devices
Although the current DOC 9137 makes no specific reference to SFFF’s in Chapter 8, we can draw a comparison with the statement in 8.1.7.6 that film-forming foams should aim for expansion ratios of 6–10 with 25% drain times in excess of 3 minutes, whereas protein-based foams should have expansion ratios of 8–12 with 25% drain times in excess of 5 minutes.
As SFFF’s are (with the exception of one claimed product) non-film-forming, the foam qualities as expressed for protein-based foams are desirable for achieving the best performance with an SFFF. The question that regional fire chiefs will need to ask is whether their discharge devices (Roof Monitors, HRET, Bumper Turrets, and handlines) can all achieve those foam qualities.
Viscosity
AFFF and FFFP remain the two types of foam concentrate that we find in use in the regional Airport F&RS, and both are low viscosity (Newtonian). The vast majority of the pumping/proportioning systems on the ARFF vehicles are designed to operate with these Newtonian fluids. With some ARFF vehicles, adjustment is possible to allow the use of higher viscosity foam concentrates such as the Enviro USB, but for many, the pumping/proportioning just cannot handle the viscosity of an SFFF like Enviro USB.
Where adjustment is possible, or when new ARFF vehicles are being specified for MENA region airports, our recommendation is that proportioning capable of handling higher viscosity foam concentrates be included, as the drain time with Enviro USB far exceeds the requirements of ICAO Level B and the new US Mil Spec for Fluorine Free Foam (MIL-PRF-32725). This improved drain time is directly related to foam blanket security, which is of critical importance in the ARFF mission.
To meet the market requirements for transition in ARFF vehicles that cannot operate with the Enviro USB, Fomtec has developed a low viscosity ICAO product marketed under the name Enviro AIR. In approval testing by MPA Dresden to ICAO Level B, Enviro AIR achieved full extinguishment of the fire pan in 75 seconds (120 seconds allowed), and the burnback time was 22 minutes 10 seconds (minimum required: 5 minutes).
For the US market, Fomtec has developed another low viscosity product to meet and exceed the MIL-PRF-32725 specification. Enviro MIL is currently undergoing QPL approval testing. As with all Fomtec products, Enviro MIL has been developed with what we term in-built safety, meaning achieving the critical performance pass numbers of extinguishing and burnback with as much of a safety margin as possible. For Enviro MIL, fire tests with gasoline and jet A1 have pass times for extinguishment of 60 seconds and 30 seconds on the 28 ft² fires with fresh product. Enviro MIL has achieved 40 seconds and 22 seconds for those fires (approximately 30% safety margin on the pass times).
What Are the Other Issues with Transitioning to SFFF in the ARFF Mission?
Tactics & Technique Differences
Foam performance is improved if applied gently to limit the disturbance of the fuel. Without the oleophobic (oil-repelling) characteristic of the fluorinated surfactant in AFFF’s and FFFP’s, direct plunging of the foam stream into the fuel should be avoided. Foam application techniques such as Roll-On, Bank-Down, and Rain-Down have been proven effective with SFFF. A mixture of techniques will likely be the best solution for effective fire attack and foam blanket management. Testing and practice in the field will be necessary.
- Foam Blanket Management
- Factors affecting foam blanket integrity include:
- Poor proportioning
- Incorrect application rate
- Presence of hot objects
- Walking/driving through the blanket
- Weather conditions (temperature, wind, rain)
- Water streams diluting the foam blanket
- Dry chemical agents reducing drain time
- Holes in the foam blanket requiring reapplication
- Training
- Challenges in training operators for SFFF include:
- Existing PFAS-contaminated training facilities
- Transition from propane-based simulations
- Need for new training facilities
- Budget approvals for training
- Ongoing training costs
- Performance evaluation
Cleaning Existing Equipment & Disposal of PFAS-Containing Foam
There is currently no legislation in the region governing PFAS disposal. Discussions between airports and local authorities are needed to determine acceptable cleaning procedures. Cleaning methods range from water rinses to water/solvent mixtures. PFAS chemicals can leach into new SFFF over time. Incineration at 1,100°C or greater remains the only disposal option in the region.
Final Thoughts
Dubai International, Al Maktoum International, and Sharjah International have already transitioned to Fluorine Free Foam. Even without legislation similar to that in Europe and the USA, other airports in the region are expected to follow suit. Fomtec offers high-performance, high-viscosity (Enviro USB) and low-viscosity (Enviro AIR) products for the ARFF mission. Both products offer in-built safety, and we welcome the opportunity to discuss the data behind the PASS certificates available on our website, as well as understanding the challenges you face in making the transition.
For more information, visit www.fomtec.com.
