NOT FOAMS!!! Chemicals predominantly designed for Class B hydrocarbon fuels. However, since they have some wetting capability, they have often been marketed as a Class A agent.
Encapsulators work on Class B hydrocarbon fuels by encapsulating the molecules or drops, preventing it from further vapor emissions. Since it is a wetting agent, it will wet Class A combustibles, however, since it is not a foam, it has no additional heat absorption capabilities beyond water. Additionally, using encapsulators on Class A fires may leave chemical residues on furnishings and structural surfaces. Encapsulators are not carbon loving and will not stick to ordinary combustibles.
Emulsifiers are products that contain enzymes that alter the hydrocarbon fuel into inert substances, so they no longer emit flammable vapors. Emulsifiers may also work as a wetting agent to reduce surface tension. But again, emulsifiers are not Foams.
NOTE: Encapsulators will instantly destroy an existing foam blanket – insure your second due resources are trained up and properly equipped to assist and not interfere with your intentions.
CLASS A FOAM does this:
- Reduces surface tension
- Attaches to carbon (clings to Class A fuels)
- Creates bubbles to increase the water’s surface area for faster heat absorption.
CLASS B PRODUCTS (Emulsifiers & Encapsulators) do this:
- Reduce the water’s surface tension
Some encapsulators have been known to be corrosive to brass. Proportioners often incorporate brass components. Check with your proportioner manufacturer prior to using encapsulators in your system.
Recently, some departments have experienced this corrosion problem. It generally starts <1 year after loading the encapsulator into the Foam Proportioning System. The first sympton is leaks caused by the destruction of the plumbing join compounds. The second sympton is noticing a bluish color caused my the product pulling the copper out of the brass. the 3rd sympton is the failure or seizing up of the concentrate pump system caused my the corrosion of the parts. Total destruction (it starts immediately) might take 1+ years to occur on a pump designed to outlast a firefighter’s career.
Is your product a CLASS A FOAM or an Encapsulator? Read the SDS and know the product before working with it. Ask other local departments that have or had the same type product.
Remember, you are responsible for what you put on the ground.
The below paragraph pertains to all firefighting surfactant products (including encapsulators and emulsifiers).
NOTE: While the Class B foam market sorts out the issues, specs and acceptable Class B products, CompressedAirFoam.com recommends continuing with the use of Class A Foam concentrates for the best effect on Class A Fire and then purchasing and DIY – Performance Evaluating small amounts of the available Class B capable foams. Keep in mind that Performance Evaluation means getting out and working with the product to see what it will and will not do. Research is showing that A/B foams do not work the same as the banned flourine B-foams. Firefighters can be both caught off guard and possibly put into a dangerous situation if they are not aware of the differences and try to test a foam product for the 1st time on a real emergency. DO NOT ever take a sales person’s word on any product. Get out and work with it. DO NOT put the product on the engine and assume it will do what you want on the first emergency.
