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 | n-Hexane |
| CASR number | 110-54-3 |
| Molecular formula | C6H14 formula weight 86.177 |
| Synonyms | n-hexane; normal hexane; hexyl hydride; skellysolve B; dipropyl; gettysolve-b; hex |
Physical and chemical properties Physical properties: Colourless liquid with a mild petrol-like odour detectable at 65 to 248 ppm. It evaporates very easily into the air. It is miscible with alcohol, chloroform, and ether. slightly soluble 0.000947 g/100 mL Melting Point (°C): -95 Boiling Point (°C): 68.7 Specific Gravity: 0.659 Vapour Density: 2.97 1 ppm = 3.52 mg/m3 Chemical properties: |
|
Common uses N-hexane is a chemical extracted, and further quantities synthesised, from crude oil. It is used in laboratories, primarily when it is mixed with similar chemicals to produce solvents. Common names for these solvents are commercial hexane, mixed hexanes, petroleum ether, and petroleum naphtha. The major use for solvents containing n-hexane is to extract vegetable oils from crops such as soybeans, flax, peanuts, and safflower seed. They are also used as cleaning agents in the textile, furniture, shoemaking, and printing industries, particularly rotogravure printing. N-hexane is also an ingredient of special glues that are used in the roofing, shoe, and leather industries. N-hexane is used in binding books, working leather, shaping pills and tablets, canning, manufacturing tires, and making baseballs. |
|
Sources of emissions Point sources Releases from industries producing, using or handling hexane. For example, rubber and plastics products industries, oil refineries, chemical plants, footwear manufacturing, petrol, and paints and adhesives. Diffuse sources, and point sources included in aggregated emissions data Releases from service stations; evaporation of fuels during petrol refilling; underground storage tanks that leak. Releases during use of adhesives, paints, and paint thinners. Natural sources Hexane is a natural constituent of crude petroleum. It also occurs naturally as a plant volatile and can be released from volcanoes. Also occurs naturally in, forest fires, and some plants. Mobile sources Vehicle exhaust. Evaporation of vehicle fuels from motors and vehicle fuel tanks. Consumer products which may contain n-Hexane Consumer products that contain small amounts of n-hexane include petrol, rubber cement, type-over correction fluids, non-mercury (low temperature) thermometers, alcohol preparations, and aerosols in perfumes. N-hexane is also a component of preparations such as paint thinners, general-purpose solvents, degreasing agents, and cleaners. |
|
Health effects How might I be exposed to n-Hexane? The most probable route of human exposure to hexane is by inhalation. Individuals are most likely to be exposed to hexane in the workplace. Monitoring data indicate that hexane is a widely occurring atmospheric pollutant. By what pathways might n-Hexane enter my body? Hexane evaporates very quickly and so the most common exposure is from breathing air containing hexane. It can also enter via the skin. Relative health hazard On a health hazard spectrum of 0 - 3 n-Hexane 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: Maximum 8 hour time weighted average (TWA) exposure: 176 mg/m3 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 n-Hexane have on my health? The only people known to have suffered ill-health effects from n-hexane were exposed to it at work. Exposure to n-hexane can cause toxicity in peripheral nerves, muscle wasting, and atrophy. It can cause numbness to the feet and hands and muscle weakness in the feet and lower legs, which can lead to paralysis of the arms and legs. It can also cause dermatitis, nausea, confusion, jaundice, and coma. |
|
Environmental effects Environmental Fate Due to its high volatility and low solubility in water, hexane in the environment will be mainly in the atmosphere. In the atmosphere, hexane is expected to exist almost entirely in the vapour phase due to its relatively high vapour pressure. The dominant tropospheric loss process for hexane is by reaction with the hydroxyl (OH) radical. The calculated half-life and lifetime of hexane due to reaction with the OH radical are 1.8 days and 2.6 days, respectively. The products of the OH radical-initiated reaction include 2-hexanone, 2- and 3-hexyl nitrate and 5-hydroxy-2-pentanone. Environmental Transport Hexane is carried in the air. If released to soil, hexane will usually quickly evaporate to the atmosphere. Hexane is only slightly soluble in water, but is readily absorbed by the lipid phase (fatty parts) of aquatic organisms, which can result in transport in the environment. Relative hazard to the environment On an environmental spectrum of 0 - 3 n-Hexane registers 1.7. 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 See the Additional Information page for current environmental guidelines. No national guidelines. What effect might n-Hexane have on the environment? Because of its very low solubility in water and high volatility, it will usually be rapidly transported to the atmosphere without major damage to the biota. In the atmosphere it is one of the volatile organic substances that contribute to the formation of photochemical smog, through interaction with nitrogen dioxide and ozone. |
|
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. n-Hexane was ranked as 89 out of the 208 ranks. Total hazard score (human health + environmental criteria) = 3.  |
|
Sources of information used in preparing this fact sheet
|
|