Methane: general information
Updated 28 October 2024
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This publication is available at https://www.gov.uk/government/publications/methane-properties-uses-and-incident-management/methane-general-information
Overview
Methane is a colourless, highly flammable gas which is the primary component of natural gas. It may also be referred to as biogas, or marsh gas. It may be stored and/or transported under pressure as a liquid-gas.
Natural gas is odourless. Therefore, to help people detect any leaks a harmless chemical is added to it to make it easier to smell. It is described as a rotten egg or hydrogen sulphide smell.
Uses of methane
Domestic gas in the UK is mostly composed of methane. Being a major constituent of natural gas, methane is used for cooking and heating. In industry, methane is also used to refine petrochemicals and to produce plastics, fertilisers, anti-freeze and fabrics.
Methane gas from animal and landfill waste is captured and used to generate heat and electricity.
How methane gets into the environment
Natural methane is found below the ground and under the seabed. It is present at lower levels in the Earth’s atmosphere. It is produced naturally from the decay of natural material such as plant and animal matter. Sources of methane include wetlands and volcanoes.
Methane may also be formed and released to the environment as a result of human activities. Livestock, manure, leaks from gas distribution networks and landfill waste all represent sources. When released into soil or water methane will eventually escape into the air where it is slow to degrade.
Methane is the second most significant greenhouse gas in the UK. Greenhouse gases trap and hold heat in the atmosphere which warms the Earth’s surface.
Exposure to methane
Methane is present in the atmosphere; therefore, the general public may be exposed to very low levels when breathing in air. Low level exposure to methane can also occur from the use of natural gas products or gas appliances in the home.
Low level exposure from the environment or from the correct use of natural gas products and gas appliances would not be expected to cause adverse health effects.
Occupational exposure to methane may occur in the workplace where it is extracted, produced or used.
How exposure to methane could affect your health
The presence of methane in the environment does not always lead to exposure. In order for it to cause any adverse health effects, you must come into contact with it. You may be exposed to methane by breathing it, or by skin contact with it. Following exposure to any chemical, the adverse health effects by which you may encounter depend on several factors, including the amount to which you are exposed (dose), the way you are exposed, the duration of exposure, the form of the chemical and if you were exposed to any other chemicals.
Low level exposure from the environment or from the correct use of natural gas products and gas appliances would not be expected to cause adverse health effects.
High levels of methane can reduce the amount of oxygen breathed from the air. This can result in mood changes, slurred speech, vision problems, memory loss, nausea, vomiting, facial flushing and headache. In severe cases, there may be changes in breathing and heart rate, balance problems, numbness, and unconsciousness. If exposure is large or continues for a longer period it can kill.
Contact of the skin or eyes with liquefied methane released under pressure may cause frostbite.
Methane and cancer
Methane is not thought to cause cancer in humans.
Pregnancy and the unborn child
There is limited data available on the direct effects of exposure methane on pregnancy and the unborn child. Therefore it is not possible to draw any definitive conclusions. Effects on the unborn child are more likely to occur if the exposure to methane causes the mother to become unwell.
Low level exposure to methane in the environment and from the correct use of natural gas products or appliances would not be expected to harm the mother or the unborn child.
Children
Children exposed to high levels methane are expected to show similar effects to adults.
Methane containing products should be stored out of the reach of children.
What to do if you smell gas in your home
If you can smell gas, call the National Gas Emergency Number on 0800 111 999.
Open doors and windows to ventilate the property.
Put out naked flames and don’t smoke.
Don’t turn off or on any power or light switches.
Turn off the meter at the control handle unless the meter is in the cellar
What to do if you are exposed to methane
Low level exposure to methane in the environment or from the correct use of natural gas products and appliances would not be expected to cause any adverse health effects. However, if you have any health concerns regarding exposure to methane seek guidance from your GP or contact NHS 111.
Additional sources of information
UKTIS – Exposure to domestic/natural gas (methane) in pregnancy
NHS - Burns and scalds
HSE - Domestic gas health and safety
National Grid – Emergencies and safety advice
British Geological Survey – The greenhouse effect
The information contained in this document from the UKHSA Radiation, Chemicals, Climate and Environmental Hazards Directorate is correct at the time of its publication.
Email chemcompendium@ukhsa.gov.uk if you have any questions about this guidance or enquiries@ukhsa.gov.uk if you have any other questions.
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