While most alcoholic drinks contain ethanol, methanol is a toxic form of alcohol that should never be consumed. Methanol poisoning is a serious and potentially life-threatening medical emergency. The risks have been highlighted in the media following a number of high-profile cases, particularly following a suspected methanol poisoning incident in Laos in which six travellers died.
Methanol poisoning is often linked to contaminated, counterfeit or illegally produced alcohol, but can also occur through exposure to industrial products.
Here we will look at methanol poisoning, its symptoms, risks, treatment and prevention…
What Is Methanol?
Methanol is a type of alcohol that is far more toxic than ethanol, the alcohol used in alcoholic drinks. It may be present in alcoholic drinks in trace amounts from distillation processes, but larger amounts will only be present in deliberately laced or accidentally contaminated alcoholic drinks.
Methanol is also known as wood alcohol because it was initially produced by distilling wood. It is used in a number of products, including paints, varnishes, paint thinners and antifreeze. In the past, it was used in alcohol-based products not meant for human consumption, such as methylated spirits and surgical spirits. However, the European Commission has recommended a new methanol-free formulation for alcohol that is not for consumption.
What Is Methanol Poisoning?
Methanol poisoning occurs when a person ingests methanol, which is broken down into highly toxic byproducts, including formaldehyde, formate and formic acid. This does not occur immediately, and drinking methanol-laced alcohol may initially feel the same as regular alcohol. The damage can occur hours later as the body attempts to clear it from the system by breaking it down in the liver.
Methanol poisoning can cause a range of symptoms, including vomiting, abdominal pain, vertigo, hyperventilation, breathlessness, blurred vision and/or blindness, coma and convulsions. It can be fatal.
How Does Methanol Poisoning Occur?
Methanol poisoning often occurs through drinking counterfeit or illegally produced alcohol that is laced with methanol alongside or instead of ethanol. Because methanol looks and tastes like regular alcohol, it can be very difficult to detect.
The Foreign Office has issued travel warnings and a list of countries where this practise is known to have occurred, following a rise in cases of death and serious illness.
Methanol poisoning can also occur from home-distilled spirits (‘moonshine’), accidental ingestion and the deliberate drinking of products not for human consumption – generally in desperation when a person is dependent on alcohol and has no access to regular alcoholic drinks.
What Are the Early Symptoms of Methanol Poisoning?
Early symptoms after initially imbibing methanol can include:
- Headache
- Dizziness
- Nausea and vomiting
- Abdominal pain
- Fatigue
- Difficulty concentrating
These symptoms can easily be mistaken for regular alcohol intoxication and/or a subsequent hangover.
How Does Methanol Poisoning Affect Vision?
Methanol can be highly toxic to the optic nerve and retina, particularly through the production of formic acid. Methanol-induced optic neuropathy is a serious condition that may result in long-term or irreversible visual impairment or even blindness.
Methanol poisoning can also cause blurry vision, light sensitivity, ‘snowfield vision’ (like seeing snowy static on an old TV) and tunnel vision.
Can Methanol Poisoning Be Fatal?
Yes, methanol poisoning is extremely dangerous and can be fatal, especially if emergency treatment is not sought quickly. It is difficult to accurately gauge the scale of the issue but a report in The Guardian suggested there may be many thousands of deaths globally each year.
Serious methanol poisoning symptoms can include:
- Respiratory failure
- Organ damage
- Seizures
- Coma
- Permanent blindness
- Death
How Long Does It Take for Symptoms to Appear?
Apart from the initial intoxication symptoms, more serious methanol poisoning symptoms generally appear between 12-48 hours after consumption. This is because it takes time for the toxic byproducts, including formaldehyde, formate and formic acid, to form and take effect.
How Is Methanol Poisoning Diagnosed?
According to Médecins Sans Frontières, it is important to establish whether an individual may have been exposed to methanol, through bootleg or alcohol from an unknown source, and to consider if others from the same environment are exhibiting similar symptoms. The timeline can also be important, as symptoms showing in less than 12 hours are unlikely to be from methanol.
As well as observing symptoms, a range of lab tests can be carried out to determine if methanol is present or rule it out.
How Is Methanol Poisoning Treated?
Methanol poisoning is treated with emergency medical and supportive care. Antidote treatments can be used to block the action of the methanol poisoning. Ethanol is often used as an antidote but should only be delivered in a strictly controlled manner – self-treating with alcoholic drinks containing ethanol should NOT be attempted. A cleansing process known as haemodialysis may be required in severe cases. Healthcare teams will also monitor the patient for complications.
Can You Recover From Methanol Poisoning?
You can certainly recover from methanol poisoning, especially if treated early. Factors that can affect recovery include the amount taken, the severity of poisoning and overall health. There can, however, be a risk of lasting complications, including visual impairment and neurological damage.
How Can You Reduce the Risk of Methanol Poisoning?
There are a number of things you can do to reduce the risk of methanol poisoning, including:
- Avoid counterfeit alcohol and homemade spirits
- Purchase alcohol from reputable sources
- Practise proper storage of industrial products that may contain methanol
- Be aware when travelling in areas where counterfeit alcohol may be more common
The Link Between Alcohol Misuse and Methanol Poisoning
Individuals with alcohol dependency may be at greater risk. Severe alcohol dependence can sometimes increase vulnerability to consuming unsafe alcohol products. These could include bootleg products. Some people may also seek out products containing methanol that are not intended for human consumption.
When Should You Seek Help for Alcohol Misuse?
Methanol poisoning only occurs when methanol is consumed in significant amounts, but ethanol poisoning – commonly referred to simply as alcohol poisoning – can also be extremely dangerous. Chronic or heavy drinking can also have serious long-term impacts on your physical and mental health. Repeated alcohol-related health scares, risky drinking behaviours or signs of dependence may indicate a need for professional support such as alcohol rehab.
While methanol poisoning is often associated with contaminated alcohol, it also serves as a reminder of the broader risks linked to alcohol misuse. It is always best to seek professional support if alcohol use is affecting your health, safety or wellbeing.
