A refined petroleum fraction used as a fuel for heating and cooking, jet engines, lamps, and weed burning, and as a base for insecticides. Kerosine, known also as lamp oil, is recovered from crude oil by distillation. It boils in the approximate range of 350–550°F (180–290°C). Most marketed grades, however, have narrower boiling ranges. The specific gravity is about 0.8. Determined by the Abel tester, the flash point is not below 73°F (23°C), but usually a higher flash point is specified. Down to a temperature of −25°F (−32°C), kerosine remains in the liquid phase. Components are mainly paraffinic and naphthenic hydrocarbons which are in the C₁₀–C₁₄ range. A low content of aromatics is desirable except when kerosine is used as tractor fuel.