Owner of Jones Mineral Cabinet, Geology and Paleontology Supervisor, interested in Earth and Planetary sciences. #1. Clastic or Detrital Sedimentary Rocks The class(t)ic route begins with the weathering and erosion of sedimentary, igneous, or metamorphic rocks.
A flame retardant is a chemical substance that is added to materials during their manufacturing process in order to both reduce the likelihood of the finished product catching fire and slow down combustion. Source: GreenFacts.
Class A foam is used as a fire retardant in 2.5 gallon [APW] and [CAFS] extinguishers to contain incipient brush fires and grass fires by creating a fire break. Other chemical retardants are capable of rendering class A material and Class B fuels non-flammable and extinguishing class A, class B, and some class D fires.