In terms of mechanical foam, human beings began to use synthetic foam fire extinguishing agents at the beginning of last century. However, the effect of synthetic foam in treating oil fires is not ideal, so people have developed protein foam, water film-forming foam, fluoroprotein foam and film-forming fluoroprotein foam. In order to deal with alcohol fire, people developed anti-alcohol foam.

(1) protein foam extinguishing agent

The water decomposition product of 1 protein and the sub-aqueous solution of sulfuric acid were placed as two kinds of aqueous solutions respectively. When in use, they are mixed with air and stirred until foaming. Later, they added ferrous sulfate as a thickener to the protein hydrolysate, and developed the current protein foam. Their 5% concentration is mixed with fresh water and seawater to form a mixed solution, which produces 8 times of foam and can stay on the surface of oil stably.

(2) Fluoroprotein foam extinguishing agent

Fluoroprotein foam. Fluoroprotein foam has good fluidity and is not easy to defoam when it is polluted by oil. It can be used in the form of underwater spray. Then the National Foam Company, Angus Company and ICI Company also made the liquid of fluoroprotein foam and sold it in the market as FP-70. In Europe and America, it quickly replaced protein foam as the mainstream fire extinguishing agent to protect large oil tanks.