Asphalt bitumen is non-toxic and is comprised of hydrocarbons and organic material with a high molecular density. These hydrocarbons are adhesive and form strong bonds with solid surfaces when at a low temperature. Crude oil deposits are formed when organic carbon material decays. The oil deposits on earth are formed from organic life and plant material that existed during the prehistoric and Jurassic era

 Bitumen,dense, highly viscous petroleum -based hydrocarbon that is found in deposits such as oil sqands  and pitch lakes (natural bitumen) or is obtained as a residue of the distillation of crude oil  (refined bitumen). In some areas, particularly in the iran bitumen is often called asphalt(asphalt) , though that name is almost universally used for the road-paving material made from a mixture of gravel, sand, and other fillers in a bituminous binder. Bitumen is also frequently called tar, it is an unsung hero of our modern world. A crucial component of the asphalt we use to build roads, bitumen holds our city streets together and connects cities and countries across vast distances. It provides a backbone for personal and business travel, tourism and logistics.

Bitumen is also sometimes confused with petroleum pitch which, although also derived from crude oil, is a substance produced by a different process from that used for refined bitumen. Petroleum pitches are the residues from the extreme heat treatment or “cracking” of petroleum fractions. Their properties and chemical composition are therefore quite different from those of bitumen