Large flammable or combustible liquid fires are high risk/low frequency incidents. Water alone will not extinguish these types of fires. Foam is required to extinguish the flames and blanket the vapors. Metro Fire deploys two Type I foam units, each carrying 660 gallons of class B alcohol resistant-aqueous film forming foam or “AR-AFFF”. Firefighting foam in addition to specialized equipment and training are required to control, extinguish, and mitigate flammable/combustible liquid emergencies.   
Capabilities of Metro Fire’s two foam units include special fire extinguishers, aspirating foam nozzles, and large caliber nozzles flowing up to 1,500 gallons per minute.  Flammable or combustible liquid fires such as gasoline, diesel, and ethanol can require large quantities of foam.  
Foam 31 responds from Fire Station 31 in Fair Oaks while Foam 114 is positioned in North Highlands at Fire Station 114.  Each foam unit is strategically located to protect local target hazards. If requested, these foam units can quickly respond as an automatic-aid resource to neighboring fire agencies or as a state wide mutual-aid resource through the California Office of Emergency Services.