Rubber Process oil is produced by Crude oil distillation process obtained from the composition and chemical interactions and isolation material extracted called Raffinate. The primary characteristics is the presence of the double bonded mix ring carbon structure. Aromatic extracts procured from refineries are suitably blended to meet stringent specifications with different Viscosity. Heavy RPO is also an aromatic process oil with higher viscosity and is specifically developed for use as an extender oil in the manufacture of polystyrene butadiene rubber. This aromatic type of rubber process oil is dark in colour and has good solvency. It is compatible with most rubber polymers and suitable for use in the manufacture of automobile rubber tyres, belting, battery case etc. where colour is not an important parameter. Heavy RPO was specially developed for use in SBS rubber.