Firefighting foam
（重定向自Class A foam）
![Firefighters sprayed foam on structures in the Mammoth Hot Springs complex on September 10, 1988 during the Yellowstone Fires.](/Images/godic/202501/04/Firefighters_spray_foam4105.jpg")
![A fire truck demonstrating Class A foam in a CAFS system](/Images/godic/202501/04/Water_Tender_CAFS_demo4105.jpg")
Firefighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, resulting in suppression of the combustion. Fire-fighting foam was invented by the Russian engineer and chemist Aleksandr Loran in 1902.