Heavy Liquid Paraffin Oil is the common name for the alkane hydrocarbons with the general formula CnH2n+2. The simplest heavy liquid paraffin oil molecule is that of methane, CH4, a gas at room temperature. Heavy liquid paraffin wax (or simply "paraffin oil", but see alternative name for kerosene, above) is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 47 °C and 64 °C, and having a density of around 0.9 g/cm3.

In industrial applications, it is often useful to modify the crystal properties of the Heavy Liquid Paraffin wax, typically by adding branching to the existing carbon backbone chain. The modification is usually done with additives, such as EVA copolymers, microcrystalline wax, or forms of polyethylene. The branched properties result in a modified Heavy Liquid Paraffin with a higher viscosity, smaller crystalline structure, and modified functional properties.