(under the class definition) Product or process in which the starting material is plant materia or a material which would ordinarily be thrown away if it were not salvaged for its fuel value.
(1) Note. "Refuse" Includes the ordinarily waste products of combustion or of fuel processing, e.g., cinders, fly-ash, soot, coal fines, etc., as well as municipal waste, industrial waste, sewage products, etc.
