Paraffin wax (or petroleum wax) is a soft colorless solid, derived from petroleum, coal or shale oil, that consists of a mixture of hydrocarbon molecules containing between twenty and forty carbon atoms. 

Paraffin wax is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 46 and 68 °C (115 and 154 °F), and a density of around 900 kg/m3.It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents but burns readily. Its heat of combustion is 42 MJ/kg.

Paraffin wax is an excellent electrical insulator, with a resistivity of between 1013 and 1017 ohm metre.This is better than nearly all other materials except some plastics (notably Teflon). 

Paraffin wax is an excellent material for storing heat, with a specific heat capacity of 2.14–2.9 J g−1 K−1 (joules per gram kelvin) and a heat of fusion of 200–220 J g−1.Paraffin wax phase-change cooling coupled with retractable radiators was used to cool the electronics of the Lunar Roving Vehicleduring the manned missions to the Moon in the early 1970s. Wax expands considerably when it melts and this allows its use in wax elementthermostats for industrial, domestic and, particularly, automobile purposes.