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A drink to die for? Avoiding methanol poisoning
by Stephen Pinco*ck and ABC Health & Wellbeing
You can't see, smell or taste it. So how would you know if a tainted Bali co*cktail or home-distilled spirit contains methanol?
Published 10/09/2013
[Image source: iStockPhoto | kvkirillov]
You can't see, smell or taste it, but drink a small amount and it could make you very ill or even kill you. It's a substance called methanol and it's recently been linked to a number of deaths in Australia and overseas.
But what exactly is methanol, how is it produced, and, more importantly, how would you know if you have drunk it?
What is methanol?
Methanol is the simplest form of alcohol. It is closely related to ethanol, the type of alcohol normally found in beer, wine and spirits but much more toxic. The potential for its presence in drinks made from home-distilled spirits is a serious health risk.
Methanol is formed in very small amounts during fermentation, the process by which alcohol is made from plant products like grape juice or cereal grains. There are small amounts in wine and beer, but not enough to cause problems when these products are made at home, says Leigh Schmidtke, a senior lecturer in wine microbiology and production at Charles Sturt University. But home distillation to make spirits like gin or rum concentrates the levels of both ethanol and methanol.
Commercially-made spirits are very safe because manufacturers use technologies specifically designed to ensure methanol is separated from the ethanol. But home brew systems are typically not so technically advanced, which makes separation more difficult.
"There are no really safe ways of differentiating methanol from ethanol at home," says Schmidtke.
Who is at risk?
The group of Australians thought most at risk of methanol poisoning are travellers, especially those travelling to countries where home-brewed spirits are widely available, such as Indonesia or Thailand.
The safest approach is not to drink any local home-brewed alcohol, although travellers are not always aware of the source of alcohol in drinks they are served. (The family of Perth carpenter Liam Davies, who died after drinking a co*cktail containing methanol in Lombok, says he thought he was drinking imported vodka and lime.)
It's speculated that locally made bootleg liquor is sometimes added to or substituted for commercially-distilled spirits in drinks sold in bars because commercial spirits are expensive. There are also reports of contaminated home-made spirits having been stored in and served from commercial spirit bottles. The 2012 death of New Zealand rugby player Michael Denton led to the New Zealand Government warning travellers that "labelling on bottles may not be accurate and substitution of contents can occur".
Home distillation is illegal in Australia, but nonetheless still happens. Equipment and instructions are readily accessible on the internet.
"The government turns a blind eye to it, so long as you make alcohol for your own consumption and don't sell it," West Australian commercial boutique rum maker, Spike Dessert, told ABC local radio in Kimberley.
"Of course, it's a lot easier to go and buy [spirits]. But it's kind of like a hobby. It's all there on the internet how to do it safely [and avoid methanol contamination], it's just that some people don't do it safely and get themselves into trouble. It's very easy to be poisoned. If they know it right away, it's treatable. But if you don't know it, well, within a few hours, it's kind of goodbye."
Despite the reports of a number of death this year, it is believed such incidents are rare.
Professor Gordian Fulde, director of the Emergency Department at Sydney's St Vincent's Hospital, says he has seen only a few patients with methanol poisoning in recent years. And only a couple of the 30,000 calls taken by Queensland's Poisons Information Centre last year related to possible methanol in alcohol made at home.
Recent Australian reports of methanol poisoning:
August 2013:
Tasmanian police and health department officials issued warnings about the dangers of drinking home-distilled spirits after the deaths of two men had been linked to a batch of moonshine that was circulating in a community on the state's east coast. Tests later found neither of the men had methanol in their system.
June 2013:
Three men Vincent Summers, 21, Joel Lynam, 21, and Bryan Wilmot, 30, die after drinking home-made grappa in Queensland. A fourth man was seriously ill but survived after treatment.
January 2013:
Perth carpenter Liam Davies, 19, died after drinking a co*cktail contaminated with methanol in Lombok.
December 2011:
Perth rugby player, Michael Denton, a New Zealander, died from methanol contaminated drink in Lombok.
Australian nurse, Jamie Johnston, suffered permanent brain damage after drinking a co*cktail containing methanol in Lombok.
Sydney woman, 18, returned home from schoolies in Bali permanently blinded after drinking co*cktail containing methanol.
Man from regional NSW, 18, suffers temporary blindness from a drink containing methanol, also in Bali.
How is methanol harmful?
Methanol is converted in the body into formic acid, the same toxin that is found in the venom of ants. It's the buildup of this in the blood that causes the devastating problems, says Professor Paul Haber, the head of Drug and Alcohol Services at the Royal Prince Alfred Hospital in Sydney.
These include:
- kidney failure
- problems with your heart and circulation,
- liver damage
- visual disturbances such as blurred vision, tunnel vision, changes in colour perception, and temporary or permanent blindness.
- nerve and brain damage
"As time progresses, you lose your vision, you're losing integrity of your thinking processes, maybe other organs are affected. It is a very, very unpleasant process," says toxicologist Professor Chris Winder.
What are the signs of methanol poisoning?
The earliest signs of methanol poisoning can be hard to distinguish from the normal effects of alcohol. You can develop mild symptoms similar to alcohol intoxication within an hour, along with nausea, vomiting and abdominal pain.
After 12 to 24 hours, the more significant symptoms can develop, such as headache, dizziness, vertigo and blurred vision.
"The bad thing is that it takes 12 to 24 hours, and often people have been solidly drunk and sleeping," says Gordian Fulde.
Ignorance of the issue can also lead to misdiagnosis or critical delays in diagnosis.
If eye symptoms such as blurred vision or difficulty looking a bright light develop, then "they really are in trouble," says Fulde. "That's when they really need to do something."
How is methanol poisoning treated?
The first piece of advice from all the experts is to quickly seek medical help if you fear you may have been poisoned with methanol.
"People know what it feels like when you've had an alcoholic drink and if something does not feel like normal alcohol intoxication then they would be concerned and should go to a hospital," says Paul Haber.
At the hospital, doctors can treat methanol poisoning by administering ethanol, which prevents the toxicity by stopping the production of formic acid.
"The sooner it is given, the better," Haber says.
Another antidote is a drug called fomepizole. Like ethanol, this drug inhibits the conversion of methanol into toxic compounds in the body. Hospitals may also use hemodialysis to clear the methanol from the blood.
