The aviation industry in Canada, like many others around the world, is undergoing a major shift in its firefighting practices as it shifts toward fluorine-free firefighting foams (FFF).
In this article, we explore the state of Canada’s transition and the opportunities in adopting FFF.
When it comes to airport firefighting, there are three separate and distinct hazards: crash rescue, hangars, and bulk fuel storage.
Each of these hazards requires different firefighting foam technology that complies with specific certifications and standards to effectively combat the fires.
Crash Rescue is one of the most dramatic events that could happen at an airport.
It is also the most time sensitive hazard and requires quick response time in order to save lives.
For crash rescue-related fires, airport fire brigades use aircraft and rescue fire fighting (ARFF) foam that follows International Civil Aviation Organization (ICAO) and MIL-SPEC 32725 specifications.
Canadian Aviation Regulations (CARs) do include an exemption (NCR-010-2024) that allows airports and heliport operators to transition to FFF.
The following is a comparison of the ICAO and MIL-Spec 32725 fire tests.
The ICAO single fire test involves three ratings, each defined by a specific flow rate: Rating “A” requires 4.10 liters per minute per square meter (Lpm/m²) or 0.10 gallons per minute per square foot (gpm/ft²), Rating “B” uses 2.50 Lpm/m² or 0.06 gpm/ft², and Rating “C” has a flow rate of 1.56 Lpm/m² or 0.04 gpm/ft².
The fire test involves a sixty-second pre-burn followed by a two-minute foam solution application, with a total of six gallons of foam solution applied.
Extinguishment must occur within sixty seconds or achieve virtual extinguishment, leaving less than 25% of the test pan with small flames and fully extinguishing the fire within the two-minute application window.
Mil-Spec 32725 defines nine different fire tests, each involving varied fire sizes and flow rates.
For a fire covering 50 square feet, the required flow rate is 3 gallons per minute (gpm), which equates to 0.06 gpm/ft² or 2.90 Lpm/m².
A fire of 28 square feet requires 2 gpm, translating to 0.07 gpm/ft² or 2.50 Lpm/m².
In the 28 square feet test, there is a ten-second pre-burn on gasoline and Jet A, followed by a ninety-second application where three gallons of foam solution are used.
The extinguishment time is set at 30 seconds for Jet A and 60 seconds for gasoline, with the foam solution applied in half strength (1.5%), full strength (3%), and double strength (6%) concentrations.
In the 50 square feet test, a sixty-second pre-burn is conducted on Jet A, followed by a ninety-second application using 4.5 gallons of foam solution.
Extinguishment must be achieved within 60 seconds at full strength.
When aircraft are being repaired and kept out of the elements, they are kept in hangars that likely contain flammable materials or liquids, which present a different type of fire hazard.
Canadian airports follow Underwriter Laboratories UL-162 and Factory Mutual (FM) 5130 for these fire hazards.
The two main differences between these fire test standards are the sprinkler spacing and sprinkler height at which the fire tests are conducted.
The UL-162 and FM-5130 standards differ in their approach to sprinkler spacing and application densities during fire tests.
Under UL-162, the sprinkler spacing is set at 12.25 feet by 12.25 feet, covering an application area of 150 square feet, while FM-5130 uses a spacing of 10 feet by 10 feet, covering an area of 100 square feet.
The methodology for determining design density also varies.
For UL-162, the test density is combined with a safety factor to calculate the design density.
In contrast, FM-5130 equates the test density directly with the design density.
The design densities for heptane, a standard hydrocarbon fuel used in fire testing, show significant variation between the UL-162 and FM-5130 standards.
For a 5.6k sprinkler on heptane, UL-162 specifies a test density of 0.10 gpm/ft² (4.1 L/min/m²) and a design density of 0.16 gpm/ft², while FM-5130 sets both the test and design densities at 0.20 gpm/ft².
For an 8.0k sprinkler on heptane, UL-162 requires a test density of 0.14 gpm/ft² and a design density of 0.22 gpm/ft², whereas FM-5130 mandates 0.30 gpm/ft² for both.
The same pattern continues for an 11.2k sprinkler, with UL-162 assigning a test density of 0.20 gpm/ft² and a design density of 0.32 gpm/ft², while FM-5130 holds both values at 0.30 gpm/ft².
The UL-162 fire test standard is conducted at a nominal height of 15 feet.
However, FM-5130 tests are performed at both low and high heights.
The high height is often constrained by the available test building height, while the low height is determined by the discharge patterns of the sprinkler system.
Firefighting at Canadian airports are governed by a combination of UL of Canada (ULC) standards, including ULC-S563 and ULC-S564, depending on the potential hazard.
Aircraft hangar protection is covered under ULC-S564, Standard for Categories 1 and 2 Foam Liquid Concentrates.
Canadian airports that transition to UL-162-listed foam benefit from a streamlined process for ULC certification, as no additional testing is required, making it a straightforward paper-based exercise.
Fuel storage tanks are arguably one of the largest fire hazards facing airport fire safety personnel.
A fire in a bulk fuel storage tank could potentially disrupt airport operations and global air travel significantly.
Such an incident could lead to airport shutdowns, causing grounded flights, diverted incoming flights, and widespread delays, resulting in millions of dollars in losses for the industry.
The specs followed to manage bulk fuel storage fires are UL-162 and FM-5130.
These specs have been used for years and have proven to be scalable and successful for large scale incidents.
In addition to these standards, some organizations opt to conduct internal testing.
This type of testing isn’t recommended because there is no real-world correlation between that testing and successfully handling a suppression event.
It is critical to have a “listed” or “approved” system with all the components being tested together and verified by an independent third party.
Other standards do exist, but the UL and FM standards are the best two to follow.
For both the UL-162 and FM-5130 fire tests, the fire size is set at 50 square feet, with an application rate of 3 gpm.
The design application density differs depending on the classification.
For Type II and Type III fires, the required densities are 0.10 gpm/ft² and 0.16 gpm/ft², respectively.
Burn-back performance, measured after five minutes, must result in less than 20% of the fire area reigniting.
New guidance for Canadian airports, expected by the end of this year, will provide updated specifications for transitioning to FFF options, aligning with ICAO standards.
With ongoing advancements in FFF technologies, Canada’s aviation industry is poised to move toward solutions that meet both safety and sustainability goals.
In 2018, Billy Bishop became the first airport in Canada to implement FFF for ARFF use.
Before they could make the transition, they had to prove the new foam was demonstrably better from an environmental standpoint.
Transport Canada approved the use of Perimeter Solutions’ SOLBERG® RE-HEALING™ RF-3, an FFF concentrate that effectively extinguishes Class B fuels while eliminating concerns about persistence in the environment, bioaccumulation, and toxic breakdown.
Multiple airports across Canada have delayed the switch and are awaiting definitive laws or mandates.
Until stricter laws are enforced, which could potentially come with the new guidance expected in the coming months, some organizations may opt to wait before investing in new firefighting foam and the new foam systems needed to deploy the solution.
Disposal of legacy foams is another cost concern.
There are dozens of organizations that offer disposal services using deep well injection, incineration, solidification to a hazardous waste landfill, and super critical water oxidation (SCWO).
Collaboration between government agencies, foam manufacturers, and environmental groups is essential to ensure the success of the transition.
Notably, partnerships with organizations like UL and GreenScreen Certified®, as well as training groups, such as the Dallas Fort Worth (DFW) Fire Training Facility, which provides invaluable support.
There are limited facilities available in Canada for burning liquid fuel, an essential part of fire training, so Canadian airport personnel often travel to DFW for training.
Airports have a unique set of hazards that follow multiple fire test standards to ensure the best-performing products are being used for these specific risks.
There is no one-size-fits-all solution for airport fire safety, and the most effective way to transition to FFF is to work with your manufacturer to make sure the correct product is being used for the correct application.
With continued collaboration among stakeholders and clearer regulations on the horizon, Canada is well-positioned to make a complete shift to fluorine-free firefighting foams in the near future.
