Substance fact sheet
The National Pollutant Inventory (NPI) provides information on the types and amounts of pollutants being emitted in the Australian community.
This page provides facts about cumene (1-methylethylbenzene). It describes how you might be exposed to this substance, how exposure might effect you and the environment, common uses, comparative data about cumene (1-methylethylbenzene) and its physical and chemical properties.
For more information about some of the terms used in this page, see the NPI glossary.
The National Pollutant Inventory (NPI) holds data for all sources of cumene (1-methylethylbenzene) emissions in Australia.
Short-term exposure to high levels of cumene results first in headache, irritation of the eyes, nose and throat, euphoria, followed by dizziness, sleepiness, and unconsciousness. Cumene is a central nervous system depressant and may cause narcotic effects. Long-term exposures at low levels have caused effects to the liver and kidneys.
Cumene will enter the body if we breathe in contaminated air, or breathe in tobacco smoke. Human exposure occurs mainly by breathing air containing cumene, from the evaporation of petroleum products. Cumene can pass through the skin.
Workers in the industries that use or produce cumene are at risk of exposure. Consumers can be exposed to cumene by exposure to air from production and processing facilities using cumene, automotive exhaust, and tobacco smoke. Consumers may also be exposed to cumene when using consumer products containing cumene (thinners for paint lacquers and enamels, foam insulation, etc) especially if there is not good ventilation.
See Sources for more information.
Worksafe Australia: For cumene, it is allowable for workers to be exposed to concentrations of 50 parts per million over an eight hour workshift.
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.
Cumene evaporates when exposed to air. In the air it is reacted quickly into other chemicals, in the water and soil bacteria break it down. It has moderate acute (short-term) toxicity on aquatic life, and high acute toxicity to birds. Insufficient data are available to predict the toxicity of cumene to plants and land animals. It has moderate chronic (long-term) toxicity to aquatic life. Cumene is expected to minimally bioaccumulate.
Industrial emissions of cumene can produce elevated concentrations in the atmosphere around the source. Because of its short life expectancy in the atmosphere cumene is expected to be confined to the local area within which it is emitted. Cumene that makes its way into the ground, and does not evaporate, is degraded in the water with in days. Because cumene 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.
Cumene evaporates to a gas if released as a liquid. It will break down in the air in a few days into other chemicals (isopropylphenols). In the water (very little will enter the water) bacteria will break it down in three to ten days. Cumene is a volatile organic chemical (VOC) and will contribute to the formation of smog.
No national guidelines.
Cumene is used to manufacture other chemicals such as phenol, acetone, acetophenone, and methyl styrene. It is used as a thinner in paints, lacquers, and enamels. It is a component of high octane motor fuels. Cumene in used in the manufacture of rubber, iron and steel, and pulp and paper.
The primary sources of cumene 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, pulp and paper manufacturing, roofing and paving, plastics manufacturing, manufacturers of paints, varnishes and lacquers. These emissions mainly are to the air, but are also to the soil and water.
Other possible emitters of cumene are vapours and spilling of petrol, commercial and household painting and paint, varnish and lacquer removal, tobacco smoke, and consumer products containing cumene. These emissions are to the air unless there is a spill.
Natural sources of cumene include crude petroleum and coal tar. It is also found in the oils of plants, marsh grasses and in some foods.
Some cumene is found in the exhaust of motor vehicles, jet engines, and outboard motors.
Some of the consumer products containing cumene are foam plastic insulation, rubber floor and wall coverings, bathmats, vinyl floor tile, wood office desks and furniture (modular) and thinners for paints, lacquers and enamels.
Approximately 400 substances were considered for inclusion on the NPI reporting list. A ranking and total hazard score was given based on health and environmental hazards and human and environmental exposure to the substance.
Cumene (1-methylethylbenzene) was ranked as 70 out of 400. The total hazard score taking into account both human health and environmental criteria is 2.2.
On a health hazard rating of 0 - 3 cumene (1-methylethylbenzene) registers 1.2. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health.
On an environmental rating of 0 - 3 cumene (1-methylethylbenzene) registers 1.0. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard.
Factors taken into account to obtain this ranking and these scores 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 account 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. 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.
| Substance name | Cumene (1-methylethylbenzene) |
| CASR number | 98-82-8 |
| Molecular formula | C9H12 |
| Synonyms | Cumol; methyl ethyl benzene; isopropylbenzene; 2-phenylpropane |
| Physical properties: Cumene is a colourless liquid with an odour similar to gasoline. Melting Point (°C): -96 Boiling Point (°C): 151 Specific Gravity: 0.862 Vapour Density: 4.1 |
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| Chemical properties: Cumene is a flammable liquid. It is insoluble in water, but soluble in most organic solvents. Flashpoint: (°C) 31 |
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There is more information that may be useful in understanding some of the issues surrounding the NPI.