Methanol is present in fuels as a petrol additive. It is used as an industrial solvent, as a solvent in a number of insecticide and fungicide formulations and is used as a reagent for chemicals such as formaldehyde, acetic acid, chloromethanes, cholesterol, antibiotics, vitamins, hormones and other pharmaceuticals. Methanol is used in antifreeze or in paint strippers, aerosol and non-aerosol spray paints, in some glass cleaners and as a fuel for picnic stoves and soldering torches. Methanol can be used as an extractant for animal and vegetable oils.
Substance name: Methanol
CASR number: 67-56-1
Molecular formula: CH4O
Synonyms: methyl alcohol, carbinol, wood alcohol, wood spirits
Methanol is a clear, colourless liquid with a characteristic odour. It is highly flammable. Methanol is used to dissolve other chemical substances and mixes readily with water and many organic liquids. Methanol is considered a volatile organic compound by the National Pollutant Inventory.
Melting point: -97.6°C
Boiling point: 64.7°C
Specific gravity: 0.7915
Flash point: 12°C
Methanol rapidly absorbs water from the air. It mixes readily with most organic liquids.
The National Pollutant Inventory (NPI) holds data for all sources of methanol emissions in Australia.
Exposure to methanol may cause irritation of the eyes, nose, mouth and throat. It can lead to liver damage, cause headaches, cardiac depression, nausea, vomiting, blurred vision, optic nerve damage, dizziness and a feeling of intoxication. Methanol exposure may lead to severe abdominal, leg and back pain.
Methanol is harmful by ingestion, inhalation or through skin absorption.
Repeated contact can dry the skin, resulting in the skin cracking, peeling and itching.
Methanol can cause temporary or permanent blindness when inhaled, ingested or passed through the skin. Exposure to high concentrations can cause coma or death.
Entering the body
Methanol can enter the body by ingestion, inhaling fumes or by absorption through the skin. Methanol will break down in the body and be removed through expired air or urine.
Exposure to methanol can also come from a wide range of consumer products containing methanol, a wide range of industries that use or produce methanol or in the environment following releases to air, water, land or ground water.
Methanol is present in low levels in the environment, it is a natural product that results from the fermentation of plants.
Currently, the eight-hour time weighted average (TWA) exposure limit is 262 milligrams of methanol per cubic metre of air. A 15-minute short-term exposure limit (STEL) of 328 milligrams of methanol per cubic metre of air has been established.
Australian drinking water guidelines:
No drinking water guidelines have been established for methanol.
Methanol may affect animals, birds and fish, leading to their death. Exposure can also cause low growth rate in plants. Long term methanol exposure can affect the fertility of biota and affect their appearance or behaviour. Methanol does not concentrate or accumulate in fish.
Entering the environment
Methanol is carried in the water and air. It is soluble in water. In air, methanol remains as a vapour for 18 days, eventually breaking down to other chemicals. Methanol is volatile, so it can be carried quite long distances. Methanol does not bind well to soil, so it can enter the groundwater.
Where it ends up
Methanol eventually evaporates when exposed to air and dissolves completely when mixed with water.
Currently, there are no Australian environmental guidelines for methanol.
Methanol is produced as a result of oil and gas extraction and from manufacturing paper and paper products, chemical products, motor vehicles and parts, wood products, metals (iron, steel and other non-ferrous metals), beverages, food and meat products.
Diffuse sources, and industry sources included in diffuse emissions data
Domestic and commercial solvents and aerosols are thought to be the highest sources of emissions
of methanol. Methanol is present in architectural surface coatings, and as a product of burning or fuel combustion activities (fuel reduction, bushfires, etc).
Methanol is produced from a wide range of microbiological processes (from decaying organic matter), heated wood and sites of geothermal activity, such as hot springs and volcanoes.
Methanol can be produced from commercial shipping activities.
Methanol is present in solvents, household cleaners, methylated spirits, fungicides and insecticides, paints and paint products (such as thinners) and in fuels for small engines.
Sources used in preparing this information
- Environment Writer, Chemical Backgrounder: methanol, accessed July 2007.
- Merck and Co. 2006, Merck Index, 14th Edition, USA.
- National Pollutant Inventory (1999), Contextual Information.
- Office of the Australian Safety and Compensation Council, Exposure Standards: Methanol, accessed July 2007.
- Technical Advisory Panel 1999, Final Report to the National Environment Protection Council.