AFFF foams are the best choice for Class B flammable fires

When choosing the best foam to fight class B flammable liquid fires, the decision maker must consider several key criteria: protecting people and critical property, putting out the fire quickly and preventing burn back while minimizing the potential impact to the environment. Based on the above criteria, decision makers continue to choose aqueous film-forming foams (AFFF) because they are the most effective agents currently available to fight Class B flammable liquid fires at airports and in military, industrial, and municipal settings. This fact has been consistently proven in fire tests conducted over the past 30 years and in tests being performed today.

DuPont fluorosurfactants are key ingredients that provide the required low surface tension and positive spreading coefficient that enables the formation of an aqueous film on top of lighter fuels. It is this film formation capability that gives foams containing DuPont fluorosurfactants their effectiveness against flammable liquid fires. AFFF agents with DuPont fluorosurfactants provide rapid extinguishment, burn-back resistance, and protection against vapour release.

Reducing Environmental Impact

Firefighting operations are a balance between extinguishing fire, saving human life or property, and the impact of these operations on the environment. This balance is best served by quickly extinguishing the fire. This allows for the protection of life and critical equipment. It also prevents or minimizes the environmental impact from combustion gases or other pollutants. 

One component of environmental impact is the potential for persistence of the long-chain perfluorinated surfactants in AFFF foams. To address this, there are several global programs which are focused on reducing or eliminating long-chain perfluorinated chemicals.  

For instance, the U.S. Environmental Protection Agency (EPA) has instituted a global stewardship program in which eight fluorochemical manufacturers have voluntarily agreed to reduce global facility emissions and product content of PFOA and related chemicals by 95 percent by year-end 2010 (and work to eliminate by year-end 2015).

As a result, telomer-based fluorochemicals that are used in firefighting foams after 2015 are not expected to contain eight (C8) and longer perfluorinated carbon chains, consistent with regulatory programs. This will likely require some reformulation and approval of many current foam products between 2010 and 2015.

In alignment with this program, as the only member of the program supplying AFFF fluorosurfactants to the industry, DuPont is transitioning its current fluorotelomer products to a new line of short-chain repellents and surfactants. DuPont™ Capstone repellents and surfactants are high performing, fluorine-efficient short-chain molecules that cannot break down to PFOA in the environment. Capstone™ repellents and surfactants are low in toxicity and are not bioaccumulative by published regulatory criteria.

Additional environmental regulation adopted by the European Union (Directive 2006/122/ECOF) has banned the use of PFOS-based (perfluorooctane sulfonate) AFFF material effective June 27, 2011. Other countries have similar programs in place or are drafting similar regulations and bans on foams containing PFOS.   

DuPont has never manufactured AFFF fluorosurfactants using PFOS, and DuPont products do not contain or break down to PFOS in the environment. Customers can have confidence that choosing an AFFF foam that contains DuPont fluorosurfactants meets regulatory requirements and are the most effective agents currently available to fight flammable liquid fires (Class B) in military, industrial, and municipal settings.

Fluorine-based foams versus Non-Fluorine based foams

Fluorotelomer-based AFFF foams are the most effective agents for fighting Class B flammable fires. AFFF foams provide the best extinguishment time and burn-back performance for all ranges of fires. Fluorine-free foams only meet the minimum certification testing requirements and may not be effective on all ranges of fire.

Fluorine-free foams are often incorrectly promoted as "environmentally-friendly" alternatives to AFFF. In fact, the environmental profile for fluorine-free foams is comparable to and in some cases worse than fluorine-containing products. In a study published by the Fire Fighting Foam Coalition, commercially available fluorine-free foams were found to be an order of magnitude higher in aquatic toxicity than AFFF foams.

With over 35 years of leadership in the science of fire suppression, DuPont is committed to develop high performing, safe, reliable products - that meet regulatory guidelines and trends.

Simply stated, fluorotelomer based AFFF foams are the best choice for fighting Class B flammable liquid fires.

For more information, visit www.capstone.dupont.com.