Methanol
Methanol is a colourless, volatile liquid. Categorized as an alcohol, methanol is commonly used as a solvent and reagent in an array of industrial applications. Outbreaks of methanol poisoning most commonly arise from the consumption of adulterated or informally produced spirit drinks (adapted from NCBI, 2024 and WHO, 2014).
Primary reference(s)
NCBI, 2024. PubChem Compound Summary for CID 887, Methanol. National Center for Biotechnology Information (NCBI). Accessed 30 Jun 2024.
WHO, 2014. Methanol poisoning outbreaks. Information Note, World Health Organization (WHO). Accessed 30 Jun 2024.
Annotations
Additional scientific description
Methanol belongs to the class of organic compounds known as primary alcohols. Methanol's chemical formula is CH3OH and is the simplest aliphatic alcohol, comprising a methyl and a hydroxyl group. It has a role as a solvent and reagent in many industrial processes; it is soluble in water and many organic solvents (NCBI, 2024).
Methanol is a widely available chemical and can be found in various household products, including varnishes, antifreeze, windscreen wash, and fuel for model aircraft. It is also used as a denaturant for ethanol. Globally, approximately 225 million litres of methanol are used each day (WHO, 2014a; WHO, 2014b).
Methanol is primarily produced by catalytic synthesis of synthesis gas (Syngas, a mixture of hydrogen and carbon monoxide) under high temperature and pressure conditions. Another production method involves the gasification of biomass (Liu, 2023).
Methanol is well-absorbed through the gastrointestinal tract and is also absorbed through the skin and by inhalation. It has a relatively low intrinsic toxicity; however, it is metabolized to highly toxic compounds including formaldehyde and formic acid, which can cause blindness, central nervous system (CNS) depression gastrointestinal disturbances, and severe metabolic disturbances that can be life-threatening. Humans have a limited ability to detoxify formic acid and this metabolite therefore accumulates and causes toxic effects (Nekourar, 2021; WHO, 2014a).
Metrics and numeric limits
Occupational Exposure Limits (OEL) published by the United States Occupational Safety and Health Administration (OSHA) and the European Chemicals Agency (ECA) include a time weighted average (TWA) permissible 8-hour exposure limit of 200 ppm (260 mg/m3) in air (OSHA, 2023; ECA, 2023).
The toxic dose of methanol varies depending on the individual and on the provision of treatment. Blood methanol concentrations above 0.500 mg/mL are associated with severe toxicity, and concentrations above 1.500-2.000 mg/mL can lead to death in untreated patients. Because patients with methanol poisoning often need intensive medical care, outbreaks of methanol poisoning can rapidly overwhelm medical facilities (WHO, 2014a).
Methanol and its formic acid metabolite were identified in the post-mortem samples of nineteen individuals who were fatally poisoned by methanol consumption during a three-month period in 2022. The compounds were identified in: biological fluids (urine, vitreous humour, bile, and cerebral spinal fluid) and tissues (muscle, kidney, liver, spleen, lung, and brain), demonstrating a wide distribution throughout the body of both methanol and formic acid. For methanol the average concentration range was 2.45-3.36 mg/mL and 2.02-3.42 mg/g for biological fluids and tissues, respectively. For formic acid, the average concentration range was 0.43-2.94 mg/mL and 0.44-0.67 mg/g for biological fluids and tissues, respectively (Tomsia 2022).
Key relevant UN convention / multilateral treaty
International Health Regulations (2005), 3rd ed. (WHO, 2016).
Sendai Framework for Disaster Risk Reduction 2015-2030.
Drivers
The informal and illicit (undocumented) production of alcoholic drinks is practiced in many parts of the world, including in countries where alcohol is banned. Alcohol produced in this format is not taxed and lacks government and market oversight. Some common names for these drinks include hooch/moonshine (USA), chang’aa/kumi kumi (Kenya), tonto/waragi (Uganda), tuak/tapai (Malaysia), samogon (Russia), and talla (Ethiopia). Such drinks are often sold in unlabelled containers in markets and at illegal drinking venues. Illicitly- or informally produced alcohol may also be sold in legitimate bars, particularly in some tourist areas. Some illicitly produced drinks are made to appear legitimate through bottle design and labelling; consumers can be misled into believing that they are buying a genuine brand of alcohol. Bottles may be sold in shops, markets and bars, often at what appears to be a discounted price (Manning, 2021; WHO, 2014a).
Impacts
Outbreaks of methanol poisoning arise from the consumption of adulterated counterfeit or informally produced spirit drinks. There have been a multitude of outbreaks between 1963-2020, including in the following countries: Bangladesh, Botswana, Cambodia, Canada, China, Costa Rica, Czech Republic, Dominican Republic, Ecuador, El Salvador, Estonia, Haiti, Honduras, India, Indonesia, Iran, Italy, Kenya, Libya, Madagascar, Malaysia, Mongolia, Nicaragua, Nigeria, Norway, Pakistan, Papua New Guinea, Poland, Russia, Saudi Arabia, Serbia, Spain, Sudan, Taiwan, Tunisia, Turkey, and Uganda. The size of these outbreaks has ranged from 10 to greater than 800 victims, with hundreds of hospitalizations and fatalities occurring within individual outbreaks in some instances (Eskandrani, 2022; Manning, 2021; Tomsia, 2022).
Multi-hazard context
The figure below summarises common interactions between methanol and other hazards. This information should be used with caution and not be solely relied upon in Disaster Risk Management, particularly as some interactions may not have been included. Note that hazardous events occurring together or locally in space or time may not necessarily cause, amplify or be otherwise related to each other. Specific examples of multi-hazard context can be found in the ‘Hazard drivers’ and ‘Impacts’ sections above.
Multi-hazard diagram
Risk Management
The WHO guidance on methanol poisoning outbreaks (WHO, 2014a) recommends the following risk management for prevention and control:
What can individuals do to protect themselves?
- Refrain from purchasing or producing illegal alcoholic drinks.
- Be suspicious about alcoholic drinks offered for sale in informal settings that are not licensed to sell alcohol, such as market stalls, and/or that are offered at a cheap price.
- Do not buy alcoholic drinks sold in unlabelled containers.
- Check branded products for labels that are poorly printed or with typographical errors, or bottles with broken seals. Do not buy these.
- Be aware of the symptoms of methanol poisoning and seek medical attention immediately if exposure is suspected.
What measures can countries take?
- Put in place a national strategy and legal framework to reduce the harmful use of alcohol.
- Use public health campaigns to promote awareness of the dangers of informally produced and illicit alcoholic drinks. These can be targeted towards particular high-risk groups, such as alcohol-dependent individuals, tourists.
- Since early recognition of an outbreak is vital to improve outcome, ensure that medical professionals are trained in the diagnosis and management of methanol poisoning.
- Where mass methanol poisonings have the potential to occur, establish a protocol for the management of these outbreaks.
- The ability of laboratories to undertake blood methanol analysis can help identify and guide clinical management of poisoned patients.
- Ensure accessible and affordable treatment is available for all, including antidotes (e.g., fomepizole, ethanol).
- Provide support to victims particularly those at risk of recurrent events, such as alcohol-dependent individuals.
The WHO is committed to reducing the health burden resulting from the harmful use of alcohol (WHO, 2014b). In 2010, the World Health Assembly endorsed a global strategy to reduce the harmful effects of alcohol. Ten recommended target areas were identified, including one addressing the need to reduce the public health impact of illicit alcohol and informally produced alcohol. Several policy options and interventions are suggested, including: developing good quality control with regard to production and distribution of alcoholic beverages; regulating sales of informally produced alcohol and bringing it into the taxation system; creating an efficient control and enforcement system, including tax stamps; developing or strengthening tracking and tracing systems for illicit alcohol; ensuring necessary cooperation and exchange of relevant information on combating illicit alcohol among authorities at national and international levels; and issuing relevant public warnings about contaminants and other health threats from informal or illicit alcohol (WHO, 2014b).
Critical elements of Early Warning Systems for methanol poisoning should involve several components to detect and respond to potential outbreaks, especially in contexts where methanol poisoning is a recurrent issue.
- Provision of training for healthcare professionals to recognize and treat methanol poisoning.
- Monitoring emergency rooms and hospitals for cases of methanol poisoning and recording of signs and symptoms of methanol consumption.
- Creating a centralized data collection and rapid reporting system, e.g., in the hospital setting and at poison control centres to facilitate ease of communication between health agencies and public health officials.
- Rapid testing of biological specimens from individuals suspected of methanol intoxication.
- Rapid testing of contaminated alcohol samples.
- Issuing public warnings and health advisories through main-stream media and social media platforms. Educating the public about the dangers of consuming non-commercial/unregulated alcohol products and recognizing the symptoms of methanol poisoning.
- Creating platforms for the public to report symptoms of potential poisonings electronically and ability to receive immediate advice from a healthcare professional.
Monitoring
The section and the table below offer an overview of monitoring methanol. This information can be used for forecasting within a national early warning system (EWS). Since EWS capacities and processes differ across countries, the most current and specific information regarding EWS should be obtained from the appropriate national or regional agency/authority responsible for disaster management.
| Which institution(s) produce(s) Disaster Risk Data/Information? | World Health Organization (WHO) |
| How is the Hazard Observed/Monitored/ Forecast? | Monitoring emergency rooms and hospitals for cases of methanol poisoning and recording of signs and symptoms of methanol consumption Centralized data collection and rapid reporting system, e.g., in the hospital setting and at poison control centres to facilitate ease of communication between health agencies and public health officials |
References
Eskandrani, R., Almulhim, K., Altamimi, A., Alhaj, A., Alnasser, S., Alawi, L., Aldweikh, E., Alaufi, K., Mzahim, B., 2022. Methanol Poisoning Outbreak in Saudi Arabia: A Case Series. Journal of Medical Case Reports, 16:357.
European Chemicals Agency, 2023. Substance Infocard, Methanol. Accessed 05 July 2024.
Liu, G., Hagelin-Weaver, H., Welt, B., 2023. A Concise Review of Catalytic Synthesis of Methanol from Synthesis Gas. Waste, 1(1):228-248.
Manning, L., Kowalska, A., 2021. Illicit Alcohol: Public Health Risk of Methanol Poisoning and Policy Mitigation Strategies. Foods 2021, 10, 1625.
NCBI, 2024. PubChem Compound Summary for CID 887, Methanol. National Center for Biotechnology Information (NCBI). Accessed 12 Jun 2024.
Nekoukar, Z., Zakariaei, Z., Taghizadeh, F., Musavi, F., Banimostafavi, E. S., Sharifpour, A., Ghuchi, N. E., Fakhar, M., Tabaripour, R., Safanavaei, S., 2021. Methanol Poisoning as a New World Challenge. Annals of Medicine and Surgery, 66:102445.
Poluzzi, A., Guandalini, G., Guffanti, S., Martinelli, M., Moioli, S., Huttenhuis, P., Rexwinkel, G., Palonen, J., Martelli, E., Groppi, G., Romano, M. C., 2022. Flexible Power and Biomass-To-Methanol Plants With Different Gasification Technologies. Frontiers in Energy Research, 9:795673.
Occupational Health and Safety Administration, 2023. Methyl Alcohol Methanol) Exposure Limits. Accessed 05 July 2024.
Tomsia, M., Głaz, M., Nowicka, J., Cie´sla, J., Sosnowski, M., Chełmecka, E., 2022. Fatal Methanol Poisoning Caused by Drinking Industrial Alcohol: Silesia Region, Poland, April–June 2022. Toxics, 10:800.
UNECE, 2023. Globally Harmonised System (GHS) of Classification and Labelling of Chemicals (2023). United Nations Economic Commission for Europe (UNECE). Accessed 12 May 2024.
WHO, 2014a. Methanol poisoning outbreaks. Information Note, World Health Organization (WHO). Accessed 12 Jun 2024.
WHO, 2014b. Global Status Report on Alcohol and Health, 2014. World Health Organization (WHO). Accessed 12 Jun 2024.