What is a Wetting Agent?

Water is the most obvious and abundant substance used to fight fires.  It is universally available and has great absorption capacity. However, there are some instances when water alone won’t cut it. Enter: the wetting agent.

In the simplest terms, a wetting agent is a solution added to water to reduce its surface tension, thereby increasing its penetration and absorption capabilities.  By weakening the cohesive properties of water and increasing its adhesive properties, wetting agents, in essence, make water wetter. Used for Class A fires (those involving ordinary combustibles) and non-water-soluble Class B fires (those involving flammable or combustible liquids), water that’s treated with wetting agents enhances its permeability and allows for better surface area coverage. Wetting agents allow water to better penetrate and saturate combustible materials, cooling the surface more rapidly, expediting extinguishment and reducing the risk for reignition.   Class B foams, on the other hand, work to repel the carbons by forming a film over the liquid to suppress the burning vapors.  This can pose a risk as if this film is disrupted re-ignition can occur.

According to a 1999 National Institute of Science and Technology’s Building and Fire Research Laboratory report, wetting agents were found to improve water’s ability to provide exposure protection on vertical wood surfaces and more quickly extinguish Class A and piled tire fires.1 In one study that examined wetting agents’ ability to penetrate surface fuels, the absorption of water droplets was shown to be 40 times slower than wetting agent solutions.2 What’s more, according to the National Institute of Standards and Technology, Class A foams made with wetting agents are three to five times more efficient at fighting fire than plain water alone.3

At Firefreeze, we offer Cold Fire®, an environmentally friendly fire extinguishing agent that puts out fires faster, safer, with less water, less damage to property, and less risk to firefighters. A UL-classified wetting agent, Cold Fire has been shown to cool 21 times faster than water and works to remove heat and the fuel sources from the fire tetrahedron, preventing re-ignition.

To learn more about wetting agents or our Cold Fire line of products, contact us here.


1 https://www.firefighternation.com/firerescue/the-as-some-bs-of-foam-firefighting/#gref

2 https://link.springer.com/article/10.1007/s10694-016-0640-0

3 https://link.springer.com/article/10.1007/s10694-016-0640-0

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