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Monday
Feb012016

Foam Properties 103.2

Some of the unique properties of the various types of firefighting vapor suppression and fire extinguishment foams have gotten sacrificed in the name of improvement. As Foam technology and improvement has been made, it has been through the advancement of compromise as to properties. While advancement has been made in one element of property enhancement, another has been sacrificed to achieve these goals.

This often happens in properties chemistry, but one department needs may be reduced while others increase. When defining which Foam is best for your department, the concept of “Balance” must be kept in mind. Depending on the nature of your type of response for your particular area, along with the availability of a Foam concentrate, you may have to sacrifice beneficial properties in the name of over-all progress. Therefore, your choice should approach a “yin/yang” type of consideration when choosing a Foam concentrate for your operations.

Let us take a closer look at some of the differences you have to pick from. As we stated the properties in Foam 103, let us look at the individual elements that should surround your decisions when choosing a Foam concentrate for your Department.

  1. Foam Protein Concentrate –

While this product was inexpensively available “pre-WWII” it functions very well with lower volume flammable liquid fires. Its main benefit was its stable molecular structure making it VERY resistant to bubble breakdown due to the relative corrosiveness (about 5.5 on the pH scale) of internal combustion fuels. Seeing as how these were booming at this time, it was not long before the massive volume of stored fuels beckoned the cry for increased knockdown over excellent heat resistance and vapor suppression. As flammable liquid production skyrocketed to supply the growing need of the citizenry, so did storage capacity. The decision was made to begin the search for a “faster-acting” Foam concentrate. This would minimize overall damage in the advent of tank farm incidents.

  1.  Fluoro – Protein Foam Concentrate

Early in WWII the need was seen in the USN. Notable increase aboard ship from enemy attack was seeing this “need” for a faster attack as fires aboard ship were severely affecting the Navy’s functionality. The induction of Fluorine into the protein molecule was the answer. This Foam concentrate reduced the need for detailed mechanical agitation while increasing the “rate/speed” of fire knockdown and even increasing fuel tolerance to the equation. This is of critical importance when fighting ship-board fires. These fires are extremely fast and hot. With no evacuation possible aboard ship, this issue bounds to the forefront. The gentle application needed for protein Foam concentrate was no longer necessary. This facilitated its use at sea. Additionally, the industry back home could advance in the form of subsurface techniques for storage facilities. This feature became very attractive to fuel producers at home increasing their volume for the war effort and supply.

  1. AFFF – Concentrate

Aqueous Film Forming Foam Concentrate added “syn-dets” or synthetic detergents to AFFF producing a product that increased knockdown speed or “rate” even more. This detail was a plus and a minus for the fuel industry. While low volume fires that plagued military locations were easily extinguished, fuel resistance began to decrease. At the time, volumes were still low but life loss was high so this decision was eagerly adopted. The volume of Foam concentrate needed due to this “film” beneath the bubble surface was also a benefit. Life seemed good, faster knockdown, less volume storage of both Foam concentrate and fuel itself, with an increased life-safety factor. A Glenn Miller” type of world to live in.

  1. FFFP Foam Concentrate –

As the war ended and fuel volume increased in the US, the thought turned to rebuilding and engine motor supply as opposed to war time activities. This prompted an increase in stored fuels and an increase in destruction from tank fire farm incidents. As AFFF was a wartime great and Protein Foam concentrate a “best” for safety the answer was to combine these talents into a FFFP (Film Forming Fluoro-Protein Foam Concentrate). Adding these two elements together would be the “cats-meow” as they once said for a perfect solution. Unfortunately, while heat tolerance and fuel resistance increased, the knockdown speed decreased as well as all other elements of this Foam concentrate. The final result was a Foam concentrate that performed much as and AFFF without any “syn-dets” and average in all other properties. This ended up being a reversion to the original Protein Foam properties with a much more sophisticated chemical package inserted into the molecule, in other words, more work than it was worth.

  1. AR –AFFF Concentrate

Finally, due to environmental standards the addition of alcohol into fuels for automobiles is a marked challenge for the Foam concentrate industry. Now, fuels exhibit a high “solvent” content necessitating the need for AR – “Alcohol Resistance” into the formula. These are the first of the current “Green Foams” that we see in use today. (See Green Foam article) While these Foam concentrates are superior for our current lifestyle, if you are using some of the older versions from your resource stockpile, be aware of the limitations and the increased properties of these Foam concentrates. These factors of knowledge will make your next hazardous materials spill safer.

                  Haz Mat Mike

 

 

 

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