Methane is the primary component of biogas and natural gas which is used as a major source of fuel in the UK, both industrially and domestically. It is colourless and odourless, but is highly flammable, making it ideal for use in the home setting as well as in commercial operations. This naturally occurring gas is found at relatively low levels in the Earth’s atmosphere, and exposure to these background levels is not harmful to human health and the environment.

Industrially, methane is used in the production of agricultural fertilisers, petrochemical refinement, and in the production of plastics. Landfills and waste management systems are also sources of methane gas which is usually captured and used to provide heating and to produce electricity.

Environmental risks

While it is a common and useful gas which is generally considered safe for a range of applications, the use of methane is not without its risks, the most impactful of which is on the environment. While carbon might be the most notorious and widely produced greenhouse gas, methane is the second most problematic. Methane emissions generally occur at much lower levels than carbon dioxide, but the methane molecule is 25 times more effective at trapping heat within Earth’s atmosphere.

Methane is highly soluble in water, so it can easily leach from industrial sources or from natural reservoirs such as permafrost and underground deposits. Once leached, it evaporates from the water or soil surface and into the atmosphere where it absorbs solar radiation and contributes to the heating effect.

The gas is also produced in vast quantities by livestock and also by bacterial activity during the decomposition of waste materials. Whatever the source, the environmental effects of methane remain the same. Many industrial and commercial operations are placing a higher importance on responsible management of methane. Often these measures involve capturing methane to be used as a combustible fuel. Despite the effects of unburned methane on the environment, it does burn very cleanly, producing far lower levels of carbon dioxide than other fossil fuels do. Read more on how to measure methane emissions.

Health and safety risks of methane

One often overlooked risk of methane is that it does occur within water plumbing systems and can cause dangerous build ups. Methane is highly combustible, and when it is allowed to accumulate under pressure in water supply systems the results can be explosive. Water authorities must monitor the levels of methane found throughout their systems to avoid this risk from becoming a real danger.

Explosive combustion of methane can also take place if an undetected leak is allowed to fill a space with methane. If leaks go unnoticed for a length of time, it often takes only the smallest source of ignition to cause catastrophic damage to industrial infrastructure and also pose a serious danger to staff. Explosions are not limited to the areas with the highest concentrations. If the gas has leached into surrounding rooms or structures then they are at risk of fire damage too.

As well as a potential to cause extreme explosive events, methane exposure can pose a health risk to people and animals if concentrations are high enough. While methane is technically non toxic and is not a risk to life at low levels, it does displace oxygen and can lead to asphyxiation. This is a particular risk when teams are working in enclosed spaces where a gas leak or leaching gas has not been detected.

In humans, the symptoms of exposure to high levels of methane include nausea, headaches, shortness of breath, chest pain, slurred speech, memory loss, and impaired judgement. Unfortunately, these symptoms can go unnoticed for some time before action is taken, leading to serious injury and sometimes death.

It is also important to consider dangers that arise from handling methane. As a gas, methane is relatively easy to handle with appropriate containment. When released from a pressurised gaseous state, methane reaches temperatures low enough to cause frostbite, and these injuries affect the hands fairly frequently when appropriate precautions are not taken.

Detecting and monitoring methane levels

Natural gas leak detection and monitoring of ambient methane levels helps to reduce the frequency of methane related incidents dramatically. Properly calibrated sensors with alarm systems should be used throughout the system take a look at our range of gas analysers and gas detectors for more information.