CHEMICAL SPILLSAccidents Not Waiting to Happen
Fires are classified by the material ignited, and only Class A fires —involving wood, cloth, rubber and some plastics —respond well to water. Class A foam is typically used on structural fires because it penetrates into materials to quell flames quickly. But a recent firefighting foam spill points to a much larger problem Maine has ignored.
During 21 years working as a municipal firefighter, “I had hyper-exposure” to foam, recalled Jim Graves, director of training at the Maine Fire Service Institute. Graves entered the fire service at age 17 and was later sent to “foam firefighting school,” a weeklong training in the selection and use of these chemical fire-suppression agents.
Fires are classified by the material ignited, and only Class A fires — involving wood, cloth, rubber and some plastics — respond well to water. Class A foam is typically used on structural fires because it penetrates into materials to quell flames quickly. Class B or aqueous film-forming foam (AFFF, called “A triple-F”) targets flammable and combustible fuel fires, which water can spread.
A cascading arc of AFFF, formed by mixing a small percentage of concentrate with a high volume of water, can slide quickly across the surface of a fuel spill, creating a thin barrier that effectively deprives flames of oxygen and suppresses fuel vapors. The efficiency of AFFF relies on per- and polyfluoroalkyl substances (PFAS), a vast class of thousands of synthetic chemicals characterized by nearly unbreakable carbon-fluorine bonds.
First used in World War II, PFAS were subsequently added to hundreds of types of consumer and industrial products due to the chemicals’ ability to repel water and oil, resist heat, and reduce surface tension. Corporate documents reveal that chemical manufacturers like 3M and DuPont knew a half-century ago that fluorinated chemicals posed serious health risks. PFAS persist indefinitely in the environment and accumulate in bodies — potentially disrupting hormonal, immune and reproductive systems, and increasing the risk of various cancers.
