The pink fire retardant that are saving Los Angeles homes

Fighting deadly infernos from the air

Crews battling the deadly Los Angeles wildfires have been dropping a bright pink fire retardant across the city ahead of the advancing flames – leaving some wondering what the substance is, and how safe it is for the public and environment.

The eye-catching substance — seen coating homes, cars and yards in photographs from the evacuation zones — is called Phos-Chek, and has been used to fight fires for more than 50 years. Made by the company Perimeter Solutions, Phos-Chek is dropped on still standing plants and structures to make them flame-proof, and so prevent fires from spreading to new locations. Firefighters say the chemical is a vital tool for battling wildfires, and officials say it is safe – but others have said it could be damaging to wildlife. What is the fire suppressant, and what is it made from? Phos-Chek is made from ammonium phosphate – a salty compound similar to many common fertilizers – which is mixed with iron oxide to create its bright pink color. Manufactured as a powder, the Phos-Chek is mixed with water prior to use to give it more substance, and is generally dumped across landscapes from planes or helicopters.

January 16, 2025 | 5:45 am