Firefighting foam

Firefighting foam emerged in 1902 Baku from a teacher watching oil fires he couldn't forget. Aleksandr Loran, a Moldovan engineer teaching at a school in the center of the Russian oil industry, had witnessed the infernos that consumed Baku's oil fields—conflagrations that water only spread rather than extinguished. He sought a liquid that could actually smother petroleum fires.

The adjacent possible for foam firefighting had been building since the industrial-scale exploitation of oil began in the 1860s. Water-based firefighting was ancient, but oil floats on water and continues burning. Sand could smother fires but was impractical for large blazes. The chemistry of stable foams—gas bubbles suspended in liquid—was increasingly understood, but no one had applied it to fire suppression.

Loran's solution combined two powders with water in a foam generator. Sodium bicarbonate and aluminum sulfate reacted to produce carbon dioxide, while small amounts of saponin or licorice extract stabilized the bubbles into a persistent blanket. This 'chemical foam' would float on burning oil, cutting off oxygen and cooling the surface. Testing proved successful in 1902 and 1903; Loran patented his invention in 1904 and developed the first foam extinguisher the same year.

The technology underwent ecological succession over the following century. Protein foams using hydrolyzed animal proteins replaced chemical foam, offering better heat resistance. Fluoroprotein foams in the 1960s added synthetic surfactants that prevented oil contamination. The U.S. Navy developed Aqueous Film-Forming Foam (AFFF) in the mid-1960s using perfluorinated chemicals, creating a self-sealing film that dramatically accelerated knockdown of fuel fires.

But this evolution carried hidden costs. The PFAS compounds in AFFF—'forever chemicals' that don't break down in the environment—have contaminated groundwater around military bases and airports worldwide. By the 2000s, the same persistence that made AFFF effective was recognized as an environmental disaster. The current push for fluorine-free foams represents yet another succession, as regulatory pressure selects for new formulations.

Loran's original insight—that stable foam blankets can smother what water cannot—remains the foundation of modern fire suppression for flammable liquids, even as the specific chemistry continues to evolve under environmental and regulatory selection pressures.