As fire crews and air tankers work to block the wildfires' explosive growth, images of red clouds of fire retardant falling onto trees are common. What is it — and what's in it?

Aerial fire suppressants are generally a mixture of water, ammonium phosphate — essentially fertilizer — and iron oxide, which is added to make the retardant visible, said Daniel McCurry, a ...

Aerial fire suppressants are generally a mixture of water, ammonium phosphate — essentially fertilizer — and iron oxide, which is added to make the retardant visible, said Daniel McCurry, a ...

Daniel McCurry is the owner of Father Nature in Birmingham, Alabama. Jennifer Hatalski of North Richland Hills, Texas, is Vice President of Marketing at Calloway’s Nursery.

So, what's in it? "It's basically a mixture of water, fertilizer, and then the red color that you see is just rust," McCurry ...

Daniel McCurry, author of the Perspective accompanying the study, says, “Unfortunately, we have no idea yet how toxic [the] chloronitramide ion is, ...

Aerial fire suppressants are generally a mixture of water, ammonium phosphate — essentially fertilizer — and iron oxide, which is added to make the retardant visible, said Daniel McCurry, a ...

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

Aerial fire suppressants are generally a mixture of water, ammonium phosphate — essentially fertilizer — and iron oxide, which is added to make the retardant visible, said Daniel McCurry, a ...

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