Usually seen on the evening news as red cloud being sprayed out of an airplane, fire retardants have been widely used since the late 1950s and are extremely helpful in suppressing wildfire.
There are three classes of fire retardants. Long-term retardants are usually applied with a rotary or fixed-winged aircraft. They are 85 percent water, with 10 percent fertilizer and 5 percent coloring, usually iron oxide. The retardant is dyed for higher visibility over the drop zone. Long-term retardants can …