Methanol poisoning The Illegal Brew That Kills


Methanol, also known as methyl alcohol, wood alcohol or wood spirit, is a colourless organic alcohol with mild alcoholic odour, commonly used for various industrial purposes.

Methanol was once produced through the destructive distillation of wood -- which carried a disgusting odour and taste -- that people were hardly tempted to drink. The development of the purification process of methanol in the late 19th century has made the use of methanol easy as a substitute to ethanol in adulterating alcoholic drinks. It was reported that as late as 1910, many wines, brandies and whiskeys sold in New York contained methanol in the quantity ranging from 24% to 43%. Although there were sporadic cases of poisoning after ingestion, they were attributed to contaminants and impurities at that time instead of methanol. It was only in 1923 when a group of dock-workers in Hamburg, Germany were poisoned by chemically pure methanol that methanol poisoning became known.

According to the World Health Organization (WHO), globally, about 225 million litres of methanol is used each day. However, with the challenges in identifying cases of methanol poisoning, it is presumed that the number of reported cases is just the ‘tip of the iceberg’, underestimating the true scale of this neglected disease.

What is methanol poisoning?

Methanol is commonly used in household and daily products, for example as a solvent in inks, dyes and varnishes; as an anti-freezing liquid; and fuel for vehicles. During the COVID-19 pandemic, homemade alcohol-based sanitisers that contained excessive amounts of methanol were reported in a number of countries.

Exposure to methanol can occur through ingestion, inhalation and dermal absorption. Methanol itself is not toxic, but when ingested, it is well-absorbed through the gastrointestinal tract and liver, and transformed into formaldehyde (HCHO) which will then rapidly metabolise to become highly toxic formic acid (CHOOH) and its anion formate.

Unfortunately, the human body has limited ability to detoxify them. When these toxic formic acid and/or formate are being accumulated in the body, it may result in metabolic acidosis and multiple organ failure, blindness, brain damage, and even death.

Why would people drink methanol?

Methanol is cheap to produce when compared with ethanol, the only type of alcohol which is safe to drink. Hence, it is being illegally adulterated into alcoholic drinks for profit reasons. Unlike water, methanol dissolves in ethanol, diluting the more expensive ethanol without visible evidence of contamination. Customers can neither see, smell nor taste the methanol in these illicit beverages but are being attracted by the low price.

Only when they fall very ill will they know that they were in fact drinking toxic substances instead of chilling out. Such informal and illicit production of alcoholic drinks is happening worldwide, especially in low-income countries. Not only the local population, but also tourists often become sick from methanol poisoning.

Who is more prone to methanol poisoning?

Methanol poisoning can happen to anyone. Tainted alcoholic products are sometimes found at large gatherings such as weddings or in isolated tourist drinks. In some settings, these illicitly produced drinks are very readily available in communities. Methanol poisoning typically affects the poor – both adults and children, predominantly in low and middle-income countries. Sometimes, children can also be affected by accidentally drinking adulterated alcohol from a young age.

Statistics show that Asia has the highest prevalence of methanol poisoning worldwide with outbreaks commonly occurring in Indonesia, India, Cambodia, Vietnam, Pakistan, the Philippines, Bangladesh, and Malaysia.

How can you tell if you are just drunk or suffering from methanol poisoning?

Methanol poisoning occurs when methanol is metabolised into highly toxic formic acid and its anion formate. It takes about 12 to 24 hours to produce enough formate for symptoms of poisoning to appear if no ethanol - the most common antidote - is consumed at the same time. If there is a shorter lapse time prior to the onset of symptoms, it is unlikely to be methanol poisoning.

Symptoms of methanol poisoning include visual disturbances, hyperventilation, dyspnoea, gastrointestinal pain, vomiting, and chest pain. Without specific treatment, patients become unconscious and die within a couple of days. The symptoms typically last a few days for majority of the patients, with some exceptional cases that have continued for weeks or even months.

Can methanol kill you?

The toxic dose of methanol depends on the concentration and the treatment provided to an individual. As little as 30ml (about a mouthful) is reported to be the minimum fatal dose for an adult, and 10ml (2 teaspoons) can cause blindness. If left untreated, symptoms typically evolve into visual disturbances, coma, brain damage, and death.

If treatment is given early, deaths or severe side effects can be prevented. But, lack of awareness, delays in seeking treatment, late diagnosis, and lack of diagnostics and therapeutics are just some of the factors that lead to adverse outcomes. Thousands of people are poisoned by methanol every year. If not treated, fatality rates are often reported to be 20% to 40%, depending on the concentration of toxic methanol and the amount taken. Permanent visual damage/blindness or brain damage are common effects affecting poisoned individuals.

How is methanol poisoning treated?

The danger of methanol poisoning occurs when the methanol consumed is metabolised into its toxic byproduct (formic acid) in the body. The accumulation of these toxic substances can result in too much acid in body fluids. Hence, the aim of treatment is to prevent further metabolism using the antidote ethanol or fomepizole; buffering acidosis with bicarbonate; and using dialysis, if available, to remove methanol and its toxic byproduct from the body.

One of the most commonly used antidote for methanol poisoning is ethanol, which can be administered intravenously or orally. While effective and inexpensive, the treatment process is more complicated and intoxication can happen. Fomepizole, on the other hand, is a more effective and easy to use antidote that does not cause sedation or behavioral changes in patients. In fact, its effectiveness may reduce the need for intubation or dialysis. However, fomepizole is very expensive and unavailable in many parts of the world. The price of fomepizole varies from place to place. US pharmaceutical companies sell it for up to US$5,000 per vial while India manufacturers list their price as US$500- $600 per vial.

In 2013, fomepizole was included in the World Health Organization (WHO)’s recommended list of Essential Medicines. However, due to a lack of data on methanol poisoning and the high cost of fomepizole, this antidote is not registered in most countries or approved for emergency reserves. Doctors Without Borders is therefore advocating for increased availability and accessibility to fomepizole.

What is the difference between methanol and ethanol?

Methanol and ethanol are different types of alcohol. Of the two, ethanol is safe for human consumption. When you drink wine, beer or spirits, you are in fact consuming varying amounts of ethanol that is safe for human consumption. Methanol, on the other hand, is commonly used for industrial purposes, for example, as a solvent in inks and dyes. As it is cheaper than ethanol, some manufacturers would illegally adulterate alcoholic drinks with methanol to lower the production cost. When the amounts of methanol being consumed has exceeded beyond what the human body can tolerate, it may result in methanol poisoning.

The good news is that ethanol can be used as an antidote to methanol poisoning. Ethanol works by competing with the metabolic breakdown of methanol, thereby preventing the accumulation of toxic byproducts. However, this would require the individual to drink heavily which may result in adverse side effects, such as intoxication and liver damage. Thus, ethanol should be used for treatment if fomepizole, the drug antidote for methanol poisoning, is unavailable.

Why is methanol poisoning considered a neglected disease?

Methanol poisoning can result in a number of symptoms which are similar to other medical conditions, such as septicaemia, heart attack, stroke, or severe hangover, making it difficult to get a correct and timely diagnosis. Common misdiagnoses of methanol poisoning include “alcohol poisoning” or “sepsis”. The delay in treatment caused by a misdiagnosis is dangerous as prognosis is dependent on the how quickly treatment is initiated from point of ingestion.

On the other hand, people being affected often only seek medical care after a significant delay due to the latent period between ingestion and symptom onset, and the fear of being penalised for drinking, especially in countries with an alcohol ban. Even if they are able to seek timely medical care, healthcare workers in settings where poisonings happen may not have the knowledge or expertise to diagnose and treat methanol poisoning properly. Methanol poisoning ‘outbreaks’ can easily overwhelm medical facilities, as poisonings regularly happen in groups, for instance at gatherings and parties, with up to hundreds of people affected at a time and severe cases needing critical care.

It is reported that thousands of people suffer from methanol poisoning every year, however, this is believed to be an underestimation of the real situation. Due to the challenges in diagnosis and limited public awareness, many fatalities and ‘outbreaks’ are not being accurately reported as methanol poisoning.

What can be done to mitigate the impacts of methanol poisoning?

The lack of basic knowledge on methanol poisoning, and shortage of diagnostic equipment, are among the main obstacles in reducing the harmful effects of methanol poisoning. By raising awareness and knowledge on methanol poisoning both among the public and medical community, many lives can be saved and deaths averted within relatively small means.

Medical personnel need to be aware of specific treatment and use of antidote for methanol poisoning. Individuals should stop buying or producing illegal alcoholic drinks or liquors sold in unlabeled containers. They should also be aware of the symptoms of methanol poisoning and seek medical help immediately if relevant symptoms develop after 12 to 24 hours. Governments, meanwhile, must establish a strategy and protocol in responding to potential methanol poisoning outbreaks, and trace the source of toxic alcohol as early as possible after an incident to prevent more people from being poisoned.

How is Doctors Without Borders addressing the issue?

Established in 2012, the Methanol Poisoning initiative (MPi) is a joint venture between Oslo University Hospital (OUH) and Doctors Without Borders, looking at mechanisms to improve the survival of methanol poisoning patients globally. Doctors Without Borders aims to reduce the harmful effects of methanol poisoning globally, by strengthening medical emergency knowledge and response capacity.

Doctors Without Borders’ teams are present in countries where methanol poisoning is common, supporting national and local health authorities in responding to methanol poisoning outbreaks. In Libya, Kenya, Russia, Indonesia and Cambodia, Doctors Without Borders had facilitated multiple trainings for local Ministry of Health staff, local NGOs and Doctors Without Borders personnel. The MPi team has also developed emergency preparedness plans, and facilitated the implementation of locally adapted treatment protocols and health information posters in various settings.

In addition, Doctors Without Borders had directly intervened in three large outbreaks; more than 1,000 patients were poisoned in Libya, March 2013, with a reported case fatality rate of 10%. In Kenya, in 2014, two outbreaks resulted in 341 and 126 patients, with case fatality rates of 29% and 21%.

At the moment, MPi focuses on the following:

- To support diagnosis, treatment and educational needs in high burden areas, including the development / updating of national treatment protocols

- To raise awareness and knowledge on methanol poisoning, and develop materials for public education

- To push for greater availability and accessibility to the antidote fomepizole through the fomepizole Access Campaign

- To support efforts in the development of a simple point-of-care diagnostic tool for the screening of methanol poisoning