Pyrolysis can be stated as the use of heat to cause the chemical decomposition of organic (carbon-based) materials. It takes place in the absence or near absence of oxygen, whereas combustion (burning) can only take place if enough oxygen is present. Pyrolysis speeds up as the temperature rises. Temperatures of 430 °C (about 800 °F) or higher are commonly used in industrial applications, whereas temperatures in smaller-scale operations may be much lower. Pyrolysis produces a type of charcoal called biochar, which is made by heating wood, and coke, which is made by heating coal and is used as an industrial fuel and a heat shield. Pyrolysis also produces non-condensable gasses and condensable liquids (or tar).