Bitumens (from Latin “bitumen” – fossil resin, crude oil) are heavy or retinoid products combining hydrocarbons and their nitrogen, oxygen, sulphur and metallic derivatives. Bitumens are water-insoluble, fully or partially soluble in benzene, chloroform, carbon sulphur and other organic solvents; its density is 0.95—1.50 g/cm³. Penetration grade bitumen is classified according to Penetration (ASTM D5) and Softening Point (ASTM D36).