Product Choices

Fire Supervision must be cognizant of the choosing the right Fire Suppression Product for the job.

Going back to the Basics:

The Fire Tetrahedron; Fuel, Oxygen, Heat, Chemical Chain Reaction

Foams

AFFF is a Foam, that means it creates a skin, and it create bubbles. Its suppression property comes from its ability to separate the Fuel from the Oxygen via a layer of fluoridated chemicals and bubble layer created by a surfactant, the water drops the temperature lowering the heats of combustion. 

Wetting or "Encapsulating" Agents

This is a product which operates by a combination with the water to separate the fuel from the Chemical Chain Reaction through a dilution and cooling process. This type of suppression agent will be required in copious amounts depending upon the chemical formulation of the product and the application rates. Rates of 6% or higher may be necessary to see satisfactory results, again depending upon the product of choice. It is important to remember some products work better that others that is why it is very important to look at the NFPA test data, and even more important to test the products yourself. A wetting agent offers no burn back protection, something that all personnel must be cognizant of.

Fluorine Free Products come as Wetting Agents or Foams. F3 foams have a hard fight because they must imitate the performance of fluorinated products without the fluorine. The non-fluorinated products have had a hard time because the fluorine organic molecules are so very resistant to heat.  The switch to F3 products was necessary to avoid the incredible biological hazard posed by fluorine's organic chemicals. F3 foams have been playing catch up for the last ten years now and a product today is light years better from products of a decade ago. You will have to switch to an F3 foam at some point, AFFF and C6 products are going away that is a fact you have to live with. It is incumbent upon every department head to actually test the product that is being marketed to you. An F3 product requires a slightly different application method which is highly dependent upon generating a copious amounts of foam, very similar to the original protein based foams. F3 foams are not as tolerant to direct impingement as fluorinated types so it is imperative that personnel practice the application techniques to gain an understanding of the performance characteristics of there chosen product.

Words of warning, Recently Arizona Department of Environmental Quality had an AFFF buyback program in which they replaced all the states AFFF with a wetting agent. At the FFFA we are left scratching our heads as to who the rocket scientist was that made this decision as a Wetting/Encapsulator Agent is not the same Class of product as AFFF.  We must caution all departments who received this product that it is not a foam, it will behave very differently than AFFF or any of the F3 Foams designed to replace AFFF, in addition the product consumption will be much much higher than the former AFFF. This I guess is really the ultimate goal, just follow the money, I am sure the seller of this wetting agent is smiling all the way to the bank, but we must caution all users of this product that performance may be severely lacking and injuries may result if not used properly. If a wetting agent is best for your application use it, if a foam is best use it, but know the difference!