Why do some firefighting planes smoke red?

You may have seen this type of aircraft in newspapers and on television shows. Firefighting planes are often fired to stop the spreading fire in plantations and forests using specially prepared material. For those who don't know what it is, it just looks like red smoke, but there's a lot of chemistry behind it.

Chief among these is water, which makes up most of the material. In addition there is also a guar gum and a kind of clay to add the thickness needed for better control of the material when spreading it over fires. What adds the red color to the product is an iron oxide.

And why is this coloring?

The big reason for this is that the environments struck by red smoke can be more easily identified by firefighters on the ground - logically, this only happens when the larger flames are already controlled. In many cases, fertilizers are still added to the product. This happens to facilitate the recomposition of the affected vegetation.