Aqueous film-forming foam (AFFF) is water-based, combining several chemicals to produce a foaming effect that suppresses highly flammable fires.
Aqueous film forming foam may be manufactured with fluorosurfactants, which may contain perfluorooctanoic acid (PFOA).
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) make up the group of per- and polyfluoroalkyl substances (PFAS) chemicals, also known as “forever chemicals”.
Despite some variations, AFFF firefighting foam’s chemical makeup includes the components listed below.
Water
Water forms the base of AFFF firefighting foam.
It’s the primary extinguishing agent for its ability to absorb heat from fires and cool the fuel surfaces.
Synthetic Surfactants
Some AFFF products contain synthetic surfactants, which are responsible for the foam-forming properties of the solution.
These surfactants lower the surface tension of water.
By decreasing water’s surface tension, surfactants allow water to spread as a thin film across the fuel surface.
As a result, the firefighting foam extinguishes fires on any scale.
Fluorosurfactants
AFFF Firefighting Foam may also incorporate fluorosurfactants, which are surfactant compounds that contain fluorine atoms.
These atoms enable the firefighting foam to spread wider, facilitating large-scale firefighting efforts.
Firefighting Foam Stabilizers
Foam stabilizers help maintain the condition of the firefighting foam for long periods.
These stabilizers act as preservatives to keep the foam from breaking down or drying up too quickly.
Thickening Agents
Many brands of AFFF firefighting foam contain thickening agents to improve the longevity of the firefighting foam.
They increase the viscosity of the firefighting foam solution, enabling the firefighting foam to stick to vertical surfaces that are ablaze.
How Does AFFF Work?
AFFF firefighting foam works by creating a thin layer on top of flammable liquids, like gasoline or oil, which stops the release of dangerous vapors and cuts off the oxygen that fuels the fire.
This helps put out the fire. The foam also cools down the hot surfaces, making it harder for the fire to start again.
In short, AFFF firefighting foam helps control and extinguish liquid fires by forming a barrier, reducing oxygen, and cooling down the heat.
