The pink fire retardant that are saving Los Angeles homes

Fighting deadly infernos from the air

Does pink fire retardant harm the environment? There are some environmental concerns surrounding the use of fire retardants. A 2024 study published in the journal Environmental Science and Technology Letters found that long-term fire retardants contained toxic metals, including lead, arsenic and thallium.

The researchers, from the University of Southern California, estimated that fire retardants added more than 400 tons (380,000 kilograms) of toxic metals to the environment between 2009 and 2021. The study included Phos-Chek LC95W, which is an older Phos-Chek product recently phased out by the Forest Service. A representative of the Forest Service told NPR that for 2025, it phased out the LC95 product nationwide in favor of the newer MVP-Fx — having already switched to MVP-Fx in California — and said that data shows MVP-Fx is less toxic to aquatic life. The primary purpose of the pink dye is simply to help firefighters and pilots be accurate in creating and identifying lines of retardant. “Essentially, it lets pilots see where lines are dropped,” Horn said. “If it was clear, they wouldn’t know where the retardant lines are.”

January 16, 2025 | 5:45 am