What is toluene?

Toluene is also known as methylbenzene, phenylmethane and toluol. It was originally extracted from the tropical Colombian tree of Myroxylon balasamum which has an aromatic extract known as tolu balsam. However, toluene is also a naturally occurring compound in crude though in very low levels. It is also a by-product in the production of gasoline and coke (fuel) from coal.

Toluene is a colorless and clear liquid with a distinct smell, characteristic of the aromatic hydrocarbon family of chemical compounds including benzene.

What are the chemical properties of toluene?

Toluene is typically stable under normal usage and storage conditions but the container may burst when heated or subjected to high temperature and mishandling.

It can be highly reactive especially in the presence of heat and flame. It is chemically incompatible with strong oxidizing agents, sulfuric and nitric acids, nitrogen tetraoxide, and chlorine. When heated and made to react with a nitro group, toluene can give rise to dintrotoluene and eventually, into the volatile and explosive trinitrotoluene. It reacts strongly with oxidizing agents and may produce heat or potentially ignite or explode when not handled properly.

Where is toluene commonly used?

Toluene is a vital chemical used in the adhesive, laboratory, paint, pesticide, pharmaceuticals, and rubber industries. It is usually used as a solvent for dilution, extraction, and electroplating. The largest use for toluene, however, is in benzene production.

Toluene is usually used a solvent due to its ability to dissolve paints, silicone sealants, lacquers, adhesives, rubber, printing ink, leather tanners, and disinfectants.

This substance is also used as an enhancer and octane booster in gasoline, as a coolant in nuclear reactor systems because of its natural heat transfer properties, as well as in biochemistry experiments where toluene is used to rupture red blood cells for hemoglobin extraction.

What are the potential hazards of toluene?

Risk to Human Health

Low to moderate levels of toluene inhalation can cause confusion, tiredness, weakness, nausea, loss of memory, loss of appetite, as well as color vision and hearing loss. When exposure to toluene is discontinued, these symptoms typically disappear. On the other hand, unconsciousness, or even death, can result to inhalation of high concentrations of toluene.

Ingestion and swallowing can cause abdominal pain and spasms and other symptoms akin to those of toluene inhalation. Direct skin contact can cause irritation and toluene can be absorbed through the skin. Toluene causes severe irritation with redness and pain when it makes contact with the eyes.

There have been reports of anemia, bone marrow disorders, and decreased blood count due to constant exposure to toluene even in small concentrations. It also has a defatting capacity which results to redness and drying of the skin as well as dermatitis. Toluene is also known to aggravate existing medical conditions such as those with skin disorders and kidney or liver disorders. Alcohol consumption is known to enhance the toxic effects of toluene. It is also very harmful to pregnant women.

Risk to the Environment

Toluene has been known to have moderate toxicity to aquatic organisms although there is no significant risk for bioaccumulation. Since this substance has strong reactivity properties, when it is released into the soil, water or air, toluene evaporates to a reasonable extent. But it is expected to filter into the water table.

Toluene is a largely unstable and toxic substance when mishandled. Therefore, the need for proper handling as well as storage practices must be stressed out. Those who are constantly exposed to toluene must be given proper protection gear since prolonged exposure to toluene vapor can be very unhealthy and, in the most extreme cases, fatal.