Paraffin, or otherwise saturated hydrocarbons or alkanes, is a mixture of hydrocarbons forming part of the residue of the crude petroleum fractional distillation. The name is due to its low chemical activity. Taken from the residue of the oil distillation, which in the start is purified by repeated treatments with sodium hydroxide and sulfuric acid and washing with water. Finally is purified by overheated vapor and decolorized with charcoal. The wax is distinguished according to the melting point in soft (melting point 45-50oC), a hard (melting point 50-60oC) and liquid or liquid paraffin.