Carbon Monoxide

Primary reference(s)

WHO, 1999. Environmental Health Criteria 213: Carbon monoxide. Second Edition. International Programme on Chemical Safety, World Health Organization (WHO). Accessed 11 May 2024.

Annotations

Key relevant UN convention / multilateral treaty

United Nations Framework Convention on Climate Change (UNFCCC). Carbon monoxide, as a product of incomplete combustion, is relevant because its emissions are often associated with the burning of fossil fuels, which also produces carbon dioxide (CO2), a major greenhouse gas.

Stockholm Convention on Persistent Organic Pollutants (POPs). While carbon monoxide is not a persistent organic pollutant, the Stockholm Convention addresses the broader issue of air quality and the reduction of harmful chemicals released into the atmosphere.

Convention on Long-Range Transboundary Air Pollution (CLRTAP). This convention specifically aims to reduce and prevent air pollution, including carbon monoxide, which can travel long distances across borders.

World Health Organization (WHO) Air Quality Guidelines. The WHO provides global guidelines for air quality, including specific recommendations for acceptable levels of carbon monoxide exposure to protect human health.

Drivers

Carbon monoxide is produced when fossil fuels burn without enough oxygen. The most important source of exposure to carbon monoxide for the general public is from cooking or other fuel-burning appliances which are poorly installed, faulty or used inappropriately (including inadequate ventilation).  

Carbon monoxide can be related to: (1) Natural hazards: Example: Wildfires and forest fires can produce large amounts of carbon monoxide due to incomplete combustion of organic material. (2) Industrial Processes: Example: Industrial accidents, such as explosions or fires at manufacturing plants or refineries, can release significant quantities of carbon monoxide. (3) Urban Environments: Example: Heavy traffic and poorly ventilated urban areas can have high concentrations of carbon monoxide from vehicle exhaust. (4) Residential Heating and Cooking: Example: Improperly vented or malfunctioning heating systems and cooking appliances can produce dangerous levels of carbon monoxide indoors. (5) Climate Change: Example: Increased temperatures and altered weather patterns can influence the frequency and intensity of wildfires, thereby increasing carbon monoxide emissions.

Impacts

An example on the impacts of carbon monoxide contamination includes home boilers that are installed incorrectly, and the use of BBQs and portable generators inside homes, caravans and tents. Inhaling smoke from a house fire may lead to carbon monoxide exposure. For smokers, cigarettes are the major source of carbon monoxide. Use of shisha/hookah pipes may also lead to exposure. Exposure to low levels of carbon monoxide can occur outdoors, as it is produced by vehicle exhausts and industrial processes (PHE, 2019). 

In emergency situations where power is lost, using an improperly vented generator inside a home or building or using gas grills, charcoal grills, or hibachis indoors can lead to dangerous levels of carbon monoxide. Breathing high levels of carbon monoxide can be fatal. Breathing lower levels of carbon monoxide can permanently harm the heart and brain. Carbon monoxide tends to be more harmful to people with heart or lung disease (ATSDR, 2012). Similarly, the use of generators after meteorological and hydrological hazards such as gale, squall, storms and cyclones, can lead to dangerous levels of carbon monoxide.

Multi-hazard context

The figure below summarises common interactions between carbon monoxide 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

Measures to limit impacts of carbon monoxide exposure include: 

• Encourage means to reduce exposure in the home and indoor environment by discouraging the use of solid fuels, such as charcoal and biomass and encouraging cooking in well-ventilated spaces.
• Educate emergency services, volunteers and others to eliminate the use of generators in confined spaces where people may be exposed. This is particularly relevant during emergency and disaster response and recovery activities where main power supplies are lost.
• Public awareness campaigns contribute to prevention of carbon monoxide poisoning in residential contexts.
• Consider regulating for safe installation of indoor heating appliances.
• Separate dwelling spaces from vehicle garages.
• Discourage the indoor running of combustion engine vehicles or require adequate ventilation where this is not possible.
• Avoid cigarette smoke and smoking (particularly pregnant women and children) as these are a source of carbon monoxide (and other hazardous chemicals). 

Examples of early warning systems include detection and monitoring technologies such as CO detectors; environmental surveillance from fixed and mobile monitoring stations; and public health notifications using alert systems. 

Monitoring

The section and the table below offer an overview of monitoring carbon monoxide. 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.