What is it?

Class A Foam Concentrate is similar to high-grade dish soap. Some concentrates are high quality, and some are not!



Foam Concentrate – the soap purchased from a vendor or manufacturer.

Foam Solution – The concentrate mixed with water

Foam – A finished product of foam solution mixed with air and agitated to make the desirable bubbles.


What does foam concentrate do?

When mixed with water, it will reduce the surface tension of the water allowing the water to flow more easily and to soak into combustibles more easily.

It allows water and air to mix into bubbles, which is essential to the formation of aspirated and compressed air foams.

It causes the foam solution to become carbon loving – this results in the water clinging to carbon based fuels, resulting in less total use of and less water damage in extinguishing common (carbon based) combustibles.

It cleans things – REAL GOOD!


What is high quality concentrate and what is low quality concentrate?

Good foam concentrate will do the job you want it to do. Concentrate is used in CAF to produce a wet finished foam to extinguish fires and also used to produce a fluid finished foam (similar to shaving cream) to apply a protective blanket to a structure or other fuel. Some of the concentrates will produce a good wet foam but will not produce a good fluid foam. Some concentrates will reduce the surface tension of water, but will not produce a good bubble structure. Some concentrates will do it all. Some are produced in different regions of the country and are easier to get regionally. Some concentrates are sold by your favorite salesperson and therefore are easier to get.


How to tell what is good before purchasing?

Here are several tips to consider:


Other Considerations:

Will my concentrate brand mix with any other brand?

1st – Remember – NEVER MIX CLASS A and CLASS B concentrates. They will instantly gel and mess up your machine big time. It will result in a maintenance nightmare. A & B concentrates are totally different chemistries.  Come Class A concentrates can be mixed with no effect. Some will cause issues over time. Since each manufacturer has different formulas, it is not recommended mixing them. An easy test, however, is to pour a mix of brands in a jar and set it aside. See what it will do. If nothing happens, it would be safe to pour a new brand into your concentrate tank as the first brand empties out. Again, it is not recommended mixing brands and letting them sit in the concentrate tank.  Your salesperson may also be able to advise you if his/her brand is compatible with other brands.


Tested Concentrates

It is recommended to purchase brands that have had third party testing. The testing process is not cheap for the manufacturer, so the fly-by-night concentrates will most likely not be tested.

The USDA/US Forest Service tests submitted concentrates for Corrosivity, toxicity to forest critters, etc.  See USFS Foam Site!!

It costs about $20k and takes several months for the testing. The USFS does not test for bubble production and not every listed concentrate will produce a good finished foam in a Compressed air foam system.


UL Listing (Info coming soon!)


There is no production standard for finished foam. There is no simple way to say what is best. The best thing to do is ask around and play with it – if it does what you want – stay with it and be happy.


CLASS B Foam Concentrates

Class B foam is designed to suppress flammable vapors produced by Class B fuels. Class B foam concentrate will run in some Compressed Air Foam Systems (check with your manufacturer for flow limitations and approved concentrate brands), however it is not designed to be used on Class A Ordinary Combustible materials.  Class B Concentrate is not designed to be sprayed into someone’s home. They are two different chemicals for two different functions. Never substitute the two, and NEVER MIX THE TWO.

A few tips if both concentrates are in the station or used on the same truck (some trucks are manufactured with simultaneous A & B tanks). Note – These tips come from REAL, reported events.

Keep the stored concentrates in separate areas. A tired firefighter returning to the station at 0230 will only see the 3% on the bucket as he grabs a bucket to refill the foam tank (CAF is used at .3%). Once the 3% is mixed with the Class A in the tank, a chemical reaction instantly begins, gelling the concentrates.

AFFF stands for Aqueous Film Forming Foam – A Class B concentrate. The A does not stand for Class A concentrate.



Where to obtain (purchase) concentrate, get prices and order MSDS’s? Click here!!! - a Division of LongBear, LLC (