is the specific temperature that can be defined in two ways, depending on the ASTM test used. In ASTM-D-1015, which measures the freezing point of high-purity petroleum products (such as nitration-grade toluene), freezing point is the temperature at which a liquid solidifies. In ASTM-D-2386, which measures the freezing point of aviation fuel, freezing point is that temperature at which hydrocarbon crystals formed on cooling disappear when the temperature of the fuel is allowed to rise.