Aviation Jet Fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colourless to straw coloured in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A1, which are produced to a standardised international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance. Jet fuel is a mixture of a variety of hydrocarbons. Because the exact composition of jet fuel varies widely based on petroleum source, it is impossible to define jet fuel as a ratio of specific hydrocarbons. Jet fuel is therefore defined as a performance specification rather than a chemical compound. Aviation Jet Fuel is commonly referred to as JP54. However, this is the wrong terminology as there is no such grade of Jet Fuel. Jet A and Jet A1 are what refineries offer. Aviation Jet fuel Gas is what powers turbine aircraft engines. Worldwide, Jet Fuel is the most used low Sulphur content Kerosene. For instance, Colonial JP54 is similar to Jet A except the energy is 18.4 mj/Kg compared to the 42.8 MJ/kg of Jet A. Most importantly there is also a slight difference in additives. Aviation Jet Fuel B is used for its extremely cold weather performance. However, aviation Jet fuel Bs lighter composition makes it more dangerous to handle. For this reason, it is rarely used except in very cold climates. A blend of approximately 30% Kerosene and 70% Gasoline. Because of its very low freezing point (60 C (76 F), it is known as a wide cut fuel and has a low flash point as well. Aviation Jet Fuel B is primarily used in some military aircraft. In Canada, it is also used because of its freezing point. Aviation Kerosene standards are published as GOST10227-86. The standard consists of different properties. It separates paraffin and gasoline in the refinery. Military organisations around the world use a different classification system of JP (for Jet Propellant) numbers. Some are almost identical to their civilian counterparts and differ only by the amounts of a few additives. For instance, Jet A1 is similar to JP 8, Jet B is similar to JP 4. Military fuels are highly specialised products and are developed for very specific applications. Jet fuels are sometimes classified as kerosene or naphtha type. Kerosene type fuels include Jet A, Jet A1, JP 5 and JP 8. Naphthatype jet fuels, sometimes referred to as wide cut Jet Fuel, including Jet B and JP 4.