What Is Pink Powder Dropped At Los Angeles Wildfires

The bright pink powder seen blanketing rooftops, streets, and vehicles in Los Angeles is Phos-Chek, a widely-used fire retardant employed to combat wildfires. Over the past week, authorities have used thousands of gallons of this substance to help control the spread of devastating fires.

What is Phos-Chek?

Phos-Chek is a fire retardant manufactured by Perimeter Solutions and has been used across the United States since the 1960s. It is the most commonly used fire retardant worldwide. The bright pink color serves as a visual marker for firefighters and pilots, helping them track where the retardant has been applied. The color fades after several days due to sunlight exposure, blending into natural earth tones.

How does it work?

Rather than directly extinguishing flames, Phos-Chek is sprayed ahead of a fire, coating vegetation and other flammable surfaces. The retardant works by preventing oxygen from fueling the fire, creating a barrier that slows the spread of flames. The core components of Phos-Chek include salts like ammonium polyphosphate. The substance is durable, lasting longer than water and resisting evaporation, which makes it effective in challenging terrains where ground crews cannot easily reach.

Are there any risks?

While Phos-Chek is an effective tool in controlling wildfires, concerns have been raised regarding its environmental and health impacts. Research indicates that the chemicals in the fire retardant, including heavy metals, can be toxic to wildlife, pollute waterways, and pose risks to human health. Lawsuits have been filed over the potential violation of clean water laws due to aerial drops of fire retardants.

In response to these concerns, the U.S. Forest Service has phased out one formulation of Phos-Chek in favor of a less toxic version and imposed restrictions on its use near sensitive environmental areas, such as water bodies and habitats for endangered species. Despite the concerns, fire retardants remain a critical tool in managing wildfires, especially in the face of more frequent fires linked to climate change.