Bright Pink Fire Retardant Used to Combat Los Angeles Wildfires Raises Safety Questions

The widespread use of Phos-Chek, a vivid fire retardant, in residential areas is drawing scrutiny over its environmental and health impacts.

Phos-Chek, a bright pink fire retardant, has been deployed on an unprecedented scale to slow the spread of wildfires in Los Angeles neighborhoods.
The substance, primarily made of ammonium phosphate with added iron oxide for visibility, is designed to reduce fire intensity and prevent flames from spreading.
While effective in many cases, experts note that high winds and intense fires may limit its usefulness in certain conditions.
The U.S. Forest Service phased out an older, more toxic formulation of Phos-Chek at the end of 2024, replacing it with a less harmful version called MVP-Fx.
Though deemed 'practically non-toxic' by the EPA, concerns remain about potential environmental damage and unclear health risks from its large-scale use in populated areas.