When Water Isn’t Enough: Why Today’s Fires Demand Class A Foam
By Jerry Hughes
A Firefighting Legacy
Growing up the son of a third-generation firefighter, my early memories revolved around family dinners filled with firehouse stories. My father, uncles, and grandfather were all Chicago firefighters and often relived the most intense fires of the ’60s and ’70s. Class A Foam for fighting fires was hardly on our radar.
I remember one particular debate between Uncle Joe and Uncle Harry: Joe defended placing ladders at window ledges to save trapped occupants, while Harry argued for positioning hose lines to control the heat threatening them. These “edge of your seat” discussions were passionate, informed, and at times, heated.
To break the tension, my grandfather would chuckle and say something like, “Big fire, big water. Little fire, little water,” or “There are two things you can never come up short on at a fire: ladders and fire hose.”
I didn’t realize it at the time, but Grandpa was really discussing fire growth and water application strategy. It would be another decade or two before Class A Foam was developed.
Understanding the Strategy
In fires that have burned beyond ordinary proportions, protecting exposures becomes paramount. The old Chicago Fire Department Rule Book said:
“A fast-spreading fire requires two 2½-inch hoselines directed at the exposure buildings flanking the main fire building. Let the main body of fire burn while you protect the exposures.”
That message stuck with me when I received my own probationary firefighter binder over 37 years ago. Though today we operate under general orders and SOPs, the strategy remains unchanged: fire behavior determines flow rate and tactical decisions.
Water Alone Isn’t Enough
In 1959, the U.S. Fire Service adopted the Iowa Rate-of-Flow Formula, developed at Iowa State University, to help determine water flow requirements for structure fires. But there’s one fundamental challenge:
Water is an inefficient extinguishing agent.
While water cools and converts heat to steam, it often results in:
- Dangerous expansion of toxic fire gases
- Poor surface penetration
- Excessive water runoff and property damage
Studies by Underwriters Laboratories show that only 5-10% of water applied to a fire contributes to extinguishment. The remaining 90-95% becomes runoff.
The Modern Fireground Is More Dangerous
Fifty years ago, homes were made with wood, glass, cotton, and natural fibers. Today’s homes are packed with synthetic, petroleum-based materials that burn hotter, faster, and with more toxic chemicals.
In legacy homes, occupants had up to 29 minutes to escape before flashover. In modern homes? Sometimes just 3 minutes.
Even worse, these synthetic fuels are hydrophobic, meaning they repel water, making extinguishment harder and increasing smoke production.
How Class A Foam Changes Everything
Fortunately, there’s a simple way to make water more effective: add a Class A foam like SparkBarrier.
Class A foam for firefighting improves water’s ability to:
- Penetrate burning materials
- Reduce heat and smoke
- Stick to surfaces (not run off)
Foam contains surfactants (just like soap) that reduce surface tension. Think of how soap helps water bond with oils; Class A foam helps water bond with carbon-based fuels.
“Anything that’s wet can’t burn.”
— Mark Cummins, CAFS inventor
Adding just 1% Class A Foam concentrate per gallon of water can make a life-saving difference in today’s fire conditions.
Editor’s Note from SparkBarrier
At SparkBarrier, we’ve built on these firefighting fundamentals to create a next-generation Class A foam that gives you a tactical advantage in every scenario.
- Highly concentrated formula for stronger performance
- PFAS-free and environmentally safe
- Backed by real science and field experience
- Approved by the U.S. Forest Service
Whether you’re battling structure fires or wildland blazes, SparkBarrier is your shield in the heat of battle.
Ready to See the Difference?
Learn more about how SparkBarrier enhances your firefighting effectiveness, or request a sample today.
Jerry Hughes
Chief Consultant
Fire Consulting Services LLC
https://fireconsultingservicesllc.com/
Jerry Hughes, retired Chicago Fire Department Battalion Chief, served the Chicago Fire Department 35+ years in the rank of Firefighter, Engineer, Company Officer, and Battalion Chief and is dedicated to spreading the word about evidence-based advancements in Firefighting. He has authored training on firefighting foam through Fire Rescue 1 Academy, which is currently used in 26 States. Chief Hughes has also been published in Fire Engineering Magazine and Fire Chief Magazine on topics related to fire prevention and fire operations. He is a Certified EMT-B, Hazardous Materials Tech and has received Certification in Compressed Air Foam Systems through the Illinois Fire Service Institute.