When every second counts

By Andrew Moody

Critical criteria that are used to select an AFFF are foams that: extinguish the fire quickly and provide the best burn-back performance; have a minimal environmental impact; have a low toxicity and biopersistence profile; are approved by global regulatory agencies.

DuPont fluorosurfactants are high performing ingredients in AFFF 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 provides rapid extinguishment, burn-back resistance, and protection against vapor release.

With over 35 years of leadership in the science of fire suppression, DuPont is uniquely positioned and committed to provide high performing, safe, reliable fluorosurfactant additives for AFFF that meet regulatory guidelines and global direction.

In alignment with the U.S. Environmental Protection Agency (EPA) 2010/15 PFOA Stewardship Program, DuPont is transitioning current fluorotelomer products to Capstone™ short-chain products. 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.

The critical function of foam is to quickly extinguish the fire. This allows for the protection of life and important equipment. Preventing or minimizing the environmental impact from combustion gases or other pollutants that are present in fires is also important.

Specific to AFFF there are several global programs which are focused at reducing or eliminating long-chain perfluorinated chemicals. The European Union (Directive 2006/122/ECOF) has banned the use of PFOS-based AFFF material effective June 27, 2011. Canada and Japan have similar programs in place or are drafting similar regulations and bans on foams containing PFOS.

AFFF foams that use DuPont fluorosurfactants do not contain or breakdown to PFOS. Customers can have confidence that choosing an AFFF that uses DuPont fluorosurfactant additives meet regulatory requirements and are the most effective agents currently available to fight flammable liquid fires (Class B) in military, industrial, and municipal settings.

In summary, 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.

Additionally, fluorine-free foams are often promoted as “environmentally-friendly” alternatives to AFFF. Although such foams may not contain fluorine, their environmental profile is comparable to - and in some cases worse - than fluorine-containing products. A paper published by the Fire Fighting Foam Coalition regarding commercially available fire fighting foam agents indicates that fluorine-free foams are at least an order of magnitude higher in aquatic toxicity than AFFF agents.

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

Andrew Moody is the EMEA Business Leader for DuPont Surface Protection Solutions (SPS). Based in Paris, Andrew has held a number of assignments within SPS during the last twelve years. Prior to joining DuPont, Andrew worked in the Fine Chemical industry and has a Ph.D. in Organic Chemistry.