Regional Practice Leader at Telgian, Troy Wiltbank highlights the benefits of Aqueous Film Forming Foam, while posing the risk of prohibition in the US.

Aqueous Film Forming Foam (AFFF), a firefighting foam agent that has been utilised since the 1960’s, is one of the best products for use on flammable and combustible liquids. 

In its Alcohol Resistant (AR-AFFF) version it is just as, if not more, robust and effective in these hazard applications. However, this type of foam has been under some immense pressure regarding environmental and health risks, but before we get into the future of this product, let us talk about what it does so well. 

It is truly hard to match the performance and efficiency of AFFF on hydrocarbon hazards and AR-AFFF on polar solvent-based hazards. To truly understand AFFF, you must first understand a couple of terms.

The term “concentrate” refers to the foam product in its unmixed form, as received from the supplier and the term “solution” refers to the foam after it has been mixed with water at its proportioning rate. 

With industry standard proportioning rates at 3% through numerous proportioning devices and discharge nozzles or sprinklers, AFFF products are very versatile in providing excellent protection in challenging applications.   

These products take efficiency even further with 1% options that perform equally to the 3% versions; the ability to reduce the amount of foam concentrate you need by a third and provide the same performance is truly amazing.

For every 100 gallons of water flow through a proportioning device, the usage of foam concentrate is 1 gallon (1%) and 3 gallons (3%) which equates to large reductions on foam concentrate storage.   

AR-AFFF is different in that it contains a special “gum” or membrane additive that allows the foam solution to stay on top of the fuel surface. This is important for several reasons. 

It first functions to separate the fuel from oxygen to dilute the vapor phase below what is necessary for combustion.  Secondly, it cools the surface and finally, it creates a stable foam blanket that then prohibits fuel vapors from migrating through the blanket for reignition.   

The other advantage that these fluorinated surfactants offer with the film forming characteristics is that they do not require a lot of expansion to be effective, as opposed to non-fluorinated products.

This is reflected in the vast number of discharge devices that are listed with the AFFF family. They perform very well out of nozzles and sprinklers that are non-aspirated.   

PFOA Stewardship Program 

Unfortunately, the presence of PFAS (perfluoroalkyl and polyfluoroalkyl) in the fluorinated chemicals is the target of many states that are, or are soon to be, banning its use.

In 2006 the PFOA product stewardship program was put into motion as a result of findings in a 3M product that resulted in their AFFF being pulled from the market. The EPA worked with eight of the leading producers of per- and polyfluoroalkyl (PFAS) substances in the market. 

Another targeted chemical within this program is perfluoro octane sulfonic acid (PFOS). This chemical has not been known to be manufactured in the US since 2002 and this includes importing per Chemical Data Reporting (CDR) efforts in 2006 and 2012.  These are bio persistent chemicals in the environment, and in the human body, that do not break down. In fact, they accumulate over time.  

The short version of this program was to reduce the carbon chain molecule of all AFFF formulations of 8 or more down to what is known as a short chain of 6 or less.

At the time, this was the solution to eliminate or significantly reduce PFOS/PFOA in the formulations and thus brought forth the latest advancement in AFFF chemistry, the designation of C6 AFFF formulations.   

This new short chain formulation requirement was required of all foam manufacturers by January 1st of 2016. The products were released to market with C6 nomenclature by manufacturers.

This was a massive effort to develop and list equipment and devices, in order to meet the needs of the market with equal performance to the longer chain formulations.

The shorter chain chemistry proved challenging in trying to equal the performance of the previous long chain formulations.  All in all, this was completed quite successfully and was thought to be a huge step forward in taking AFFF into the future with the environment in mind. 

Challenges for manufacturers  

The solution to the AFFF fluorine, Fluorine Free Foam (F3) is a huge decision and it will take a massive effort to achieve. Manufacturers of F3 products will be challenged to provide products that can come close to the type of protection AFFF could provide.

Some notable performance requirements of Mil-Spec AFFF were to achieve military extinguishment standards at half the proportioning rate and twice its proportioning rate.

There are some big challenges for foam manufacturers to overcome in developing a solution such as we are seeing with F3 products. The products that are currently available have minimal listings and limitations to applications.

Some of this is due to the fact that the products are very new to the market, as compared to the AFFF family. There have also been challenges in performance and inability to meet similar application rates.   

A fundamental solution  

PFAS bans are in place and they will continue so, finding a solution is a top priority. There are many options that are close and are achieving success in very minimal applications.  In many cases though, as the flammables and combustibles get more exotic and in-depth, the performance of F3’s drops significantly. 

These regulations have put many in a very tough situation where the new technology is not equivalent yet to replace the current technology.  A proper study must be conducted in order to make the right choice for a new or existing facility or hazard.

There are many fire protection professionals, manufacturers and fire protection engineers who specialise in this type of hazard, and it is important to reach out to them when making critical decisions with fire protection products for a Class B hazard.