Methylbenzene

Methylbenzene, commonly known as toluene, is an aromatic hydrocarbon with the chemical formula C7H8. It consists of a benzene ring bearing a single methyl substituent. Toluene is a colorless, volatile liquid with a characteristic sweet, pungent odor.

Physically, toluene has a boiling point of 110.6°C and a melting point of −95.0°C. Its density is about 0.867 g/cm3 at 15°C, and it is largely insoluble in water while readily miscible with most organic solvents. It is highly flammable and presents a significant vapor hazard at room temperature.

Occurrence and production are tied to petroleum refining and coal tar processing. Toluene occurs in small amounts in crude oil and is produced commercially in large volumes from refinery streams. Industrially, it is obtained as part of toluene-rich cuts from catalytic reforming and other processing steps, making it one of the key aromatic components in petrochemical feedstocks.

Uses of toluene are broad, reflecting its properties as a versatile solvent and chemical building block. It is widely employed as a solvent in paints, coatings, inks, adhesives, and rubber processing. It also serves as a feedstock for the synthesis of various aromatic chemicals, including benzoic acid and benzaldehyde, and as a precursor for polyurethane and other specialty chemicals.

Safety and environmental considerations are important due to its flammability and health effects. Exposure can affect the nervous system, and prolonged or high-level exposure may impact liver and kidney function. It should be handled with adequate ventilation, away from sources of ignition, and stored in tightly closed containers. Spills should be contained to minimize environmental dispersion, and waste should be disposed of in accordance with applicable regulations.