What was the pink flame retardant dropped in the Los Angeles wildfires? Here's what to know.

Airplane battle Fires raging in Los Angeles area is using more than water: Hundreds of thousands of gallons of pink fire extinguishing agent have been dropped in front of the fire in a desperate attempt to prevent it from spreading and destroying more communities.

this fatal The fires have displaced thousands of residents and destroyed more than 12,000 buildings since they started last Tuesday (January 7). All four major fires were caused by intense fires. Santa Ana style About 62 square miles of land have been scorched, according to Cal Fire.

Fire agencies say suppressors – most commonly used to fight forest fires – are an invaluable tool. But what's inside them, and are they safe?

Here's what you need to know:

When to use fire extinguishing agents?

Cal Fire said the fire was burning rapidly in canyons and other rugged areas that were difficult for firefighters on the ground to reach.

The agency said that while fire extinguishing agents are very effective, they do have limitations. Strong winds can make flying at the low altitudes required for landing very dangerous and can dissipate retardant before it reaches the ground.

In addition to Cal Fire, multiple agencies dropped retardant and water, including the U.S. Forest Service, Los Angeles and Ventura county fire departments, city governments and the National Guard.

What is contained in aerial fire extinguishing agents?

Daniel McCurry, a professor of civil and environmental engineering at the University of Southern California, said aerial firefighting agents are usually a mixture of water, ammonium phosphate (essentially fertilizer) and iron oxide, which is added to make the flame retardant visible.

The Forest Service has used 13 aircraft to drop suppressants on the Los Angeles fires, which the agency says help block oxygen from the fires and slow burning by cooling and covering vegetation and other surfaces.

Perimeter, a company that supplies flame retardants to the Forest Service and other agencies, said phosphates change the way cellulose breaks down in plants, making them less flammable.

Fire extinguishing agents are generally considered safe for humans, but many are concerned about their potential impact on wildlife.

Because of potential health effects on fish and other wildlife, the Forest Service prohibits the use of aerial suppressants in waterways and endangered species habitats “unless there is a threat to human life or public safety.”

USC's McCurry said he and other researchers tested several inhibitors and found heavy metals, including chromium and cadmium, in one commonly used by the U.S. Forest Service.

McCurry said the study's results suggest it's “reasonable” that firefighting agents could cause spikes in chromium and other heavy metals in waterways downstream of wildfires.

“We don't have conclusive evidence yet because proving the source of the heavy metals is difficult, but not impossible,” McCurry said. “We're working on that.”

Perimeter, the manufacturer of the Forest Service flame retardant, said McCurry's research was on a formula not used in California and no longer used by the Forest Service. The company also says it adds no metals, which are naturally found in all ammonium phosphate fertilizers, and that its aerial inhibitors “have been exhaustively tested by the USDA Forest Service and meet or exceed all health and safety standards.”

Using flame retardants to protect the grid

Several power companies in the Los Angeles area are also using flame retardants to try to help protect poles and wires, CBS Los Angeles reporting.

Crews have been working for days, stopping as many power poles as possible on the edges of wildfires — the Palisades Fire on the coast of Los Angeles and the Eaton Fire in the mountains above Pasadena and Altadena.

First, they cleared dry brush around the poles, then used trucks to spray each pole with fire retardant — the same substance firefighting aircraft spray from above. They try to spray it as far up the pole as possible and into all the cracks so the embers can't get a foothold.

“That way, if or when a fire does happen this way, we don't have to worry about embers catching it,” said Connor Norton, one of the PG&E employees working in North Hollywood on Sunday.

“The best way to save lives”

The use of flame retardants is crucial to fighting wildfires that are putting millions at risk health riskswhich includes a toxic mixture of microscopic particles that can penetrate deep into the lungs and bloodstream, causing breathing and heart problems.

Wildfire smoke accounts for half of all health-damaging particulate air pollution in the Western United States in recent years, as rising temperatures fuel more destructive fires, research shows.

Research released by the Alzheimer's Association last year found that wildfire smoke may be more detrimental to brain health than other types of air pollution, increasing the risk of dementia.

“Using wildland fire retardants is the best way to save lives, protect communities and control fires,” said Edward Goldberg, Vice Chairman of Perimeter Solutions.

McCurry, the USC researcher, said more research on fire suppressants is needed — including in Los Angeles after the fire was extinguished — but he understands their value: “If there was a fire in my house, I would still rather There’s a lot of (fire retardant) on the front without painting.”

Dillon Thomas Dean Fioresi contributed to this report.