Substance fact sheet
The background information page contains information and concepts that will be useful in understanding some of the issues surrounding the NPI. It is strongly recommended that you read this before reading the information presented below.
For an explanation of some of the terms used in this page, see the Glossary
| Substance name | Toluene (methylbenzene) |
| CASR number | 108-88-3 |
| Molecular formula | C7H8 |
| Synonyms | Toluol; phenyl methane; methylbenzol; methyl-benzene; monomethylbenzene |
Physical and chemical properties Physical properties: Toluene is a clear, colourless liquid with a sweet smell. Melting Point (°C): -95 Boiling Point (°C): 110.6 Vapour Density: 3.13 Specific Gravity: 0.867 (at 20°C) Chemical properties: |
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Common uses The majority of toluene is used as a component of petrol. It is also used in paints, lacquers, inks, adhesives, rubber, and cleaning agents. It is used to manufacture benzene, urethane raw materials, and other organic chemicals. It is used in the production of pharmaceuticals, dyes, and cosmetic nail products. It is used against roundworms and hookworms. |
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Sources of emissions Point sources The primary sources of toluene are the industries that manufacture it or use it in production. Some of the industries that manufacture it or use it in production are oil refiners, chemical industry, rubber manufacturers, pharmaceutical industry, metal degreasing, printing, manufacturers of paints, varnishes and lacquers. These emissions mainly are to the air, but are also to the soil and water. Diffuse sources, and point sources included in aggregated emissions data Other possible emitters of toluene are vapours and spilling of petrol, commercial and household painting and paint, varnish and lacquer removal, tobacco smoke, and consumer products containing toluene. These emissions are to the air unless there is a spill. Natural sources Natural sources of toluene include volcanoes, forest and bush fires and crude oil. Mobile sources Some toluene is found in vehicle exhaust. Consumer products which may contain Toluene (methylbenzene) Adhesives, Auto polish and cleaners, floor polish, hard surface cleaners, paints, inks, paint cleaners, paint and varnish removers and thinners, coatings, particleboard, leather dressings, lubricating oils, fingernail enamels and removers, shoe polish and cleaners, solvent thinned products (exterior stains, primers, interior stains, clear finish), colouring pens and markers, wood office furniture, vinyl flooring |
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Health effects How might I be exposed to Toluene (methylbenzene)? Consumers are most likely to be exposed to toluene by smoking or using consumer products containing toluene (paints, varnish, nail polish, paint cleaners, stain removers, etc.) especially if there is not good ventilation. Because toluene is used in many consumer products, and found in tobacco smoke, short-term indoor concentrations may be elevated above the levels considered safe for workers. Workers in the industries that use or produce toluene are at risk of exposure. Consumers can also be exposed to toluene by exposure to air from production and processing facilities using toluene, and automotive exhaust. Sniffing glue or paint can also lead to high exposures. By what pathways might Toluene (methylbenzene) enter my body? Toluene will enter the body if we breathe in contaminated air, breathe in tobacco smoke, or consume food or water that contains toluene. It can also be absorbed through the skin, if liquid toluene is in contact with the skin. Human exposure occurs mainly by breathing air containing toluene. Toluene usually leaves the body with in twelve hours. Relative health hazard On a health hazard spectrum of 0 - 3 Toluene (methylbenzene) registers 1.3. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the evaluation of its tendency to cause, or not cause cancer and/or birth defects. It does not take into account exposure to the substance. Human exposure is reflected in the NPI rank given to this substance (see comparative data below). A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0.  Health guidelines Worksafe Australia:The eight hour time weighted average (TWA) exposure limit is 100 parts per million and the short term exposure limit (STEL) is 150 parts per million. Australian Drinking Water Guidelines (NHMRC and ARMCANZ, 1996): Health Maximum of 0.8 mg/L (i.e. 0.0008 g/L) Aesthetic Maximum of 0.025 mg/L (i.e. 0.000025 g/L) See the Additional Information page for current health information. The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information. Note that the emissions data in the NPI database is not directly comparable with these guidelines. What effect might Toluene (methylbenzene) have on my health? Short-term exposure to high levels of toluene results first in light-headedness and euphoria, followed by dizziness, sleepiness, unconsciousness, and in some cases death. When exposure is stopped prior to death the symptoms disappear. Long-term exposures at low levels have caused effects to the kidneys. Long-term exposures to high amounts of toluene by intentional abuse have been linked to permanent brain damage. Also reported are problems with speech, vision, and hearing, loss of muscle control, loss of memory and balance and reduced scores of psychological tests. |
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Environmental effects Environmental Fate Toluene quickly evaporates to a gas if released as a liquid. It evaporates from both water and soil when exposed to air. It will break down in the air in a few days into other chemicals (benzaldehyde and cresol, which are harmful to humans). In the soil and water bacteria will break it down. Environmental Transport Industrial emissions of toluene can produce elevated, concentrations in the atmosphere around the source. Because of its short life expectancy in the atmosphere toluene is expected to be confined to the local area within which it is emitted. Toluene that makes its way into the ground, and does not evaporate, may move through the ground and enter groundwater (bore water), it is degraded in the water with in days. Relative hazard to the environment On an environmental spectrum of 0 - 3 Toluene (methylbenzene) registers 1.3. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into exposure to the substance. Environmental exposure is reflected in the NPI rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8.  Environmental guidelines Australian Water Quality Guidelines for Fresh and Marine Waters: (ANZECC, 1992): Maximum of 300 micrograms/L (i.e. 0.0003 g/L) See the Additional Information page for current environmental guidelines. Note that the emissions data in the NPI database is not directly comparable with these guidelines. What effect might Toluene (methylbenzene) have on the environment? Toluene evaporates when exposed to air. It also evaporates from water. In the air it quickly is reacted into other chemicals, in the water and soil bacteria break it down. It has moderate acute (short-term) toxicity on aquatic life. Toluene has caused membrane damage to the leaves in plants. It has moderate chronic (long-term) toxicity to aquatic life. Chronic and acute effects on birds or land animals have not been determined. Toluene is expected to minimally bioaccumulate. |
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Comparative data NPI Rank Approximately 400 substances were considered for inclusion on the NPI reporting list. A risk ranking was given based on health and environmental hazard identification and human and environmental exposure to the substance. Some substances were grouped together at the same rank with 208 ranks in total. Toluene (methylbenzene) was ranked as 33 out of the 208 ranks. Total hazard score (human health + environmental criteria) = 2.6.  |
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Sources of information used in preparing this article
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