Toluene Definition

Toluene , also known as toluol , is an aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a CH3 group attached to a phenyl group.

Toluene was first isolated in 1837 through a distillation of pine oil by a Polish chemist named Filip Walter, who named it rétinnaphte. In 1841, French chemist Henri Étienne Sainte-Claire Deville isolated a hydrocarbon from balsam of Tolu (an aromatic extract from the tropical Colombian tree Myroxylon balsamum), which Deville recognized as similar to Walter’s rétinnaphte and to benzene; hence he called the new hydrocarbon benzoène. In 1843, Jöns Jacob Berzelius recommended the name toluin. In 1850, French chemist Auguste Cahours isolated from a distillate of wood a hydrocarbon which he recognized as similar to Deville’s benzoène and which Cahours named toluène.


Toluene Applications

  1. Used as an industrial feedstock.
  2. Used as a solvent for carbon nanomaterials Used as a precursor to benzene via hydrodealkylation.
  3. Used in the manufacture of polyurethane foam.
  4. Used as an octane booster in gasoline fuels for internal combustion engines.
  5. Used as an intoxicative inhalant in a manner unintended by manufacturers.
  6. Used as a fullerene indicator.


  1. CBI.
  2. Liquid.
  3. OtherSolid.
  4. Withheld.
  6. Sweet, pungent, benzene-like odor.
Molecular Weight 92.13
Boiling Point 110.7 oC
Melting Point -95 oC
Flash Point 40 oF (closed cup)
Vapor Density 3.2 (air = 1)
Vapor Pressure 36.7 mm Hg at 30 oC
Density/Specific Gravity 0.866 at 20/4 oC (water = 1)
Log Octanol/Water Partition Coefficient 2.69
Conversion Factor 1 ppm = 3.77 mg/m3