Fuel Oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, Oil is any liquid petroleum product, which is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash point of approximately 40 oC (104 o F). Oil is made of long hydrocarbon chains, particularly alkanes, cycloalkanes and aromatics. The term Fuel Oil is also used in a stricter sense to refer only to the heaviest commercial fuel that can be obtained from crude oil, heavier than gasoline and naphtha.