Toluene, also known as methylbenzene, is a clear, colorless liquid with a distinctive sweet smell that
is widely used in industrial settings as a solvent. Toluene is also an ingredient in some consumer
products such as paints, glues, and nail polish removers.
Toluene occurs naturally in crude oil and in the tolu tree. It is also produced during the manufacturing
of gasoline and other fuels from crude oil, as well as in making coke, a type of fuel derived from coal
used in steel production.
Toluene is typically used in the production of paints, rubber, lacquers, glues, and adhesives because it can help dry, dissolve, and thin other substances. It is used in the production process to make other chemicals, including benzene, nylon, plastics, polyurethane, and in the synthesis of trinitrotoluene (TNT), benzoic acid, benzoyl chloride, and toluene diisocyanate.
Toluene has been used as an ingredient in nail polish removers due to its ability to help dissolve other substances, such as resins and plasticizers. It has also been used in the formulation of nail products to enable nail polishes, hardeners, and lacquers to be applied smoothly.
Toluene is produced in the manufacturing of gasoline, and it is also a gasoline additive that can be used to improve octane ratings for fuel used in race cars and other automobiles.
The higher the octane number or rating, the greater the fuel’s resistance to knocking or pinging during combustion. Toluene is used in these applications because it is dense and contains significant energy per unit of volume, which enhances power generation for vehicles.
Toluene is added to gasoline, used to produce benzene, and used as a solvent. Exposure to toluene may occur from breathing ambient or indoor air affected by such sources. The central nervous system (CNS) is the primary target organ for toluene toxicity in both humans and animals for acute (short-term) and chronic (long-term) exposures. CNS dysfunction and narcosis have been frequently observed in humans acutely exposed to elevated airborne levels of toluene; symptoms include fatigue, sleepiness, headaches, and nausea. CNS depression has been reported to occur in chronic abusers exposed to high levels of toluene. Chronic inhalation exposure of humans to toluene also causes irritation of the upper respiratory tract and eyes, sore throat, dizziness, and headache. Human studies have reported developmental effects, such as CNS dysfunction, attention deficits, and minor craniofacial and limb anomalies, in the children of pregnant women exposed to high levels of toluene or mixed solvents by inhalation. EPA has concluded that there is inadequate information to assess the carcinogenic potential of toluene.
| TEST | METHOD | SPECIFICATION |
|---|---|---|
| Colour | 5 of IS : 82 -1973 | Not darker than freshly prepared solution of 0.8 ml. of 0.1N Potassium Dichromate and 12 ml. of 0.1N of Cobalt Sulphate made up to 1000 ml with water. |
| At 15/15°C | --- | 0.8700 to 0.8740 |
| At 27/27°C | --- | 0.8590 to 0.8630 |
| Distillation range | IS : 5298(1969) | The difference between temperature (running pts) at which 1 & 96% of the volume taken have been collected shall not exceed 0.6°C when a treated sample is tested by standard method. This range shall include the temperature of 110.6°C. |
| Residue on evaporation, mg/100 ml. | 9 of IS:82-1973 | |
| Total Sulphur %wt. | Appendix C of IS:537-1967 | Max.0.1 |
| Hydrogen Sulphide | Appendix D of IS:537-1967 | To pass test |
| Mercaptan | P:19 of IS:1448 | Shall give no positive reaction. |
| Conforms to specifications of IS:537-1967 Nitration grade of Toluene | ||
| In addition BPCL follows the following spec for better customer satisfaction | ||
| Acid Wash Colour | D - 848 | Not darker than No. 2 Colour Standard. |
| Distillation | IS:5298-1969 | Difference between IBP & DP shall be not more than 1°C |