Class B Firefighting Foam

Best Practices Today for Class B Firefighting Foam

• Perfluorochemicals (PFCs) are a group of chemicals developed by 3M Corp for use in products to make them water repellent, stain-resistant, slippery and longer lasting. 
• PFCs are not natural and do not seem to break down in the environment.  Once in the environment, they may be taken up by living things, and build up (bioaccumulate) within the tissue of plants, animals and people. 
• Scientists have been surprised to find PFCs in approximately 98% of all humans, including people in remote areas who have never had contact with the modern world.  Studies in Minnesota have shown PFCs to be present in some ground and surface waters, air, soil and fish.  Studies are underway to see if PFCs create health or developmental problems in people.
• PFCs are used in Class B firefighting foams to increase their effectiveness and make them long lasting.
• The Minnesota Pollution Control Agency (MPCA) is working on a study to understand the potential of firefighting foam as a source of PFCs in the environment.  Soil and groundwater at approximately 20 firefighting training sites will be evaluated for PFCs.  Minnesota Department of Health is sampling some municipal wells near foam training sites.
• Results from this work will be able late in 2009.  MPCA, MnSCU Fire/EMS/Safety Center, and Fire Marshal’s Office have developed guidelines for the training and use of Class B fire fighting foam until more answers on foam are known.

Use of foam on fires and spills

First, Class B firefighting foam has been a lifesaver.  It is meant for flammable liquid fires and flammable liquid pools, or for combustible liquid fires.  So use it if you have a flammable liquid like gasoline on fire or a big gasoline pool in a place where it could ignite or where it would do damage if it did ignite.  Don’t automatically use it for a diesel fuel spill, unless the diesel fuel is on fire or the situation is endangering life and property.  Don’t automatically blanket non-leaking flammable liquid tanks unless the situation really calls for it.

Second, don’t use Class B foam on car fires, ordinary structure fires, wildland fires, or other inappropriate situations.  Class A foams are meant for those situations, Class A foams are not thought to contain PFCs.

Foam training

Foam training sessions should include discussion of when foam use is necessary, when it can be helpful for safety, and when its use is inappropriate.

If possible, use training foams in training.  Training foams are not thought to contain PFCs.  Class B foam training should not be done near surface waters or storm sewer inlets which would allow foam to quickly drain to water. 

PFCs can quickly pass through soil to groundwater.  If your city has municipal wells your city water superintendent will have a map of the “well head protection area” which shows where the city’s wells draw their water from.  Training in those protection areas or in areas near private wells should be avoided.  Train on soil where possible, and pick organic soils as opposed to sandy and gravelly soils if possible.  That will increase the likelihood that PFCs in the foam are retained in the soil and don’t quickly wash through to groundwater.

Foam types

There are many types of PFCs.  Apparently all the AFFF type Class B foams have some PFC content of various types.  Ethanol resistant AFFF foams apparently also contain types of PFCs.   Class A foams are not thought to contain PFCs.

Firefighters’ Health

Use foams to protect the public, your firefighters, and valuable property.  There is no current concern that PFCs can enter firefighters’ bodies by occasional skin contact or inhalation during firefighting or training.

Disposal

At this time the best disposal of Class B foams is to use it appropriately on Class B flammable liquid spills and fires.  Liquids can’t be put into the garbage.  If Class B foam is sent down the sanitary sewer it will go to the city’s wastewater treatment plant and the PFCs in the foam probably will pass straight on through to the river or lake without being broken down.  So for now, the best advice is to store it safely where the containers won’t get damaged until it gets used or until there are better disposal options available.  That likely will be quite some time.

Jim Stockinger - Emergency Response Specialist    

Steve Lee – Manager Emergency Response Unit   Emergency Response and Preparedness

Minnesota Pollution Control Agency Minnesota Pollution Control Agency

also

Fire Training Captain Linwood Fire Department

Don Beckering, State Director

Jerry Rosendahl, State Fire Marshal

Fire/EMS/Safety Center                                             

Fire Marshal Division

Minnesota State Colleges and Universities

Department of Public Safety