Although methanol and ethanol are both types of alcohol, there are some important differences between them. For starters, they have different chemical structures, properties, uses, and effects. Unlike ethanol, which is present in alcoholic beverages, methanol is extremely toxic and should never be ingested.
In this article, we’ll explain more about the difference between methanol and ethanol, how they’re produced, and the potential health implications.
In this post:
Basic chemical structures of methanol & ethanol
Methanol and ethanol are both hydrocarbon derivatives. Their molecules are mainly composed of carbon and hydrogen with specific functional group/s attached to a carbon. In the case of alcohols, the functional group is hydroxyl (-OH). Despite this, methanol and ethanol are chemically and structurally different.
Ethanol
Ethanol consists of two carbon atoms, each of which has hydrogens attached to it. The hydroxyl functional group is attached to one of the carbon atoms.
Otherwise known as ethyl alcohol, it has an ethyl group in its carbon skeleton and the chemical formula CH3CH2OH. Ethanol is the only drinkable alcohol (in moderation, of course) and is the main active ingredient in alcoholic beverages such as wine, beer, vodka, gin and whiskey. As most of us know, it temporarily causes drunkenness, headaches, and nausea.
Methanol
Methanol is the simplest alcohol and, unlike ethanol, it only has one carbon. A derivative of methane, it has a methyl group in the carbon skeleton.
The chemical formula for methanol (also known as methyl alcohol) is CH3OH. It’s a highly toxic substance and is unsuitable for drinking; consuming just half a teaspoon can cause blindness and even death.
While alcohols are generally miscible with water, their solubility decreases as the hydrocarbon component increases. Consequently, methanol is more soluble in water than ethanol. The slight angular bend of the hydroxyl group also makes alcohol hydrophilic, although it becomes more hydrophobic as the number of carbons increases.
Physical and chemical properties
The physical properties of both methanol and ethanol overlap in many aspects, but there are some distinct differences. Both are volatile and flammable colourless liquids with a pungent odour. They also have relatively low boiling points.
The main differences between ethanol and methanol are shown in the table below:
Characteristic | Ethanol | Methanol |
| Chemical formula | Contains the ethyl group in its carbon skeleton | Contains the methyl group in its carbon skeleton |
| Acidity | A weak acid compared to water | A strong acid compared to water |
| Properties | Is flammable, volatile, and has a a strong, distinctive smell. It gives off a bright blue flame when burned | Is flammable, volatile, and has a a strong, distinctive smell. It gives off a bright white flame when burned |
| Production | Ethanol is typically produced by the fermentation of food crops | Methanol is usually synthetically processed |
| Uses | The main ingredient in alcoholic beverages | Should not be consumed! Methanol is used to produce other chemicals such as formaldehyde |
Difference in production methods between methanol vs. ethanol
Ethanol is traditionally and commercially produced through the fermentation process of sugars using yeast. These sugars can come from a wide variety of sources including grapes, barley, rice, corn, and wheat. In fact, any crop or plant containing large quantities of sugar like starch or cellulose can be used as feedstock.
Over 90% of the ethanol produced globally is made from the fermentation of crops, with the remainder produced by the hydration of ethene. The exact steps of fermentation vary but the basic principles are the same.
Methanol is usually made on an industrial scale via the catalytic reactions of carbon dioxide, carbon monoxide, and hydrogen. Various types of feedstock, including scrap wood, can be used to make methanol in this way.
These feedstocks are gasified to turn into carbon dioxide and carbon monoxide. The result is a synthesised mixture that is converted and distilled, creating methanol.
Health implications
Ethanol is largely used for recreational purposes and is the main active ingredient of alcoholic beverages. Although consuming ethanol can result in drunkenness, headaches and nausea, these effects are only temporary.
Drinking alcoholic beverages occasionally and in moderation doesn’t generally have long-term health implications. However, chronic heavy drinking and alcohol abuse can cause serious health problems such as liver damage and heart disease. Alcohol poisoning can even be fatal. No amount of ethanol is considered safe for pregnant women or children.
Unlike ethanol, methanol is highly toxic and should never be consumed or inhaled under any circumstances. Even an extremely small dose can cause blindness, kidney failure and, in some cases, death.
Methanol can also be dangerous if it’s absorbed through the skin. At the very least, it may cause skin irritation, cracking and dryness. To minimise the risk, always wear appropriate PPE when working with methanol. You can read more about how to handle hazardous chemicals here.
Handling and storage of methanol & ethanol
Just like other types of alcohols, methanol and ethanol are highly flammable. They should be stored in a cool, dry place and away from direct sunlight and ignition sources.
As with any chemical, methanol and ethanol must be kept in sealed containers and out of reach of children and animals.
First aid measures
Methanol poisoning is very dangerous and potentially fatal. If someone comes into contact with methanol, wash the affected area of skin with tepid water and seek medical attention. In the case of ingestion, call for an ambulance and monitor the patient until help arrives. Do not induce vomiting. If the patient stops breathing, begin CPR immediately.
Although ethanol isn’t as hazardous, it may still be necessary to give first aid to someone who’s severely intoxicated. You should encourage them to sit up (there’s a risk they could potentially choke on their own vomit) and drink some water. If they lose consciousness, put them in the recovery position and phone an ambulance.
Conclusion
Although methanol and ethanol might sound and look similar, they’re actually very different. Structurally, methanol has one carbon whereas ethanol has two. Methanol is also very toxic – consuming even just a small amount can be fatal. Ethanol, however, is generally safe to drink in moderation and is the main ingredient in alcoholic beverages like wine and beer.
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