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Published on 19/04/2022

Understanding Methane Gas and Associated Dangers

Most of us are familiar with methane as the principal component of natural gas, which is still used by millions of people worldwide to heat and power their homes and generate electricity. It’s also a clean-burning yet potent greenhouse gas – produced in abundance by animal agriculture and coal and oil production. 

Many don’t know that methane is just as deadly (if not more so) than many other well-known combustible gases. Here we investigate the dangers of methane at sea and discuss proper methane management on board sea-going vessels, including the relatively recent issue of methane slip. 

Carriage of methane on board sea-going vessels

Methane can be found onboard sea-going vessels in several capacities – including fuel for engines and cooking or heating and the carriage of methane for chemical production and biogas. Other sources include excrement onboard live export ships, decomposing plant matter or refuse and sewage storage and containers. 

LNG is a valuable commodity worldwide as it continues to be widely used as a source of electricity, heat, cooking fuel and industrial purposes. Specialist ships must carry this cooled gas, as maintaining its low temperature and continuously stabilising such large quantities is no easy task. The carriage of LNG is widespread and potentially less deadly due to the state the gas is carried in, although, in such massive volumes, the risk continues to be significant. 

One of the most significant risks sea-going vessels currently face in terms of methane is a phenomenon known as ‘methane slip’. Liquefied Natural Gas (LNG, for short) is quickly favoured for its alleged eco-credentials instead of traditional fossil fuels such as oil or gas. But LNG is susceptible to methane slip – which occurs when unburned methane is released into the atmosphere as the ship’s engine uses it. Methane is 30 times more potent than CO2, making the gas build-up on board potentially lethal, especially on larger vessels. 

The jury is still out on whether LNG is a cleaner alternative to traditional fuels (many say the advantages are minimal or non-existent) – as methane is still a greenhouse gas, as is CO2. But with more shipping companies looking to invest in a cleaner fuel solution, the possibility of methane slip (and the dangers of an undetected gas leak) becomes even greater. 


When left unchecked, a methane leak can pose an incredibly significant risk to life in several ways. 

The first concern comes with the elusive characteristics of methane. Although methane is often thought to have a pungent odour, this is added in a domestic setting to alert those around of a leak. When it is leaked in its natural state, it is completely odourless and colourless – invisible and undetectable to the naked eye. A highly sensitive gas detector is needed to identify a leak – and even a small amount of methane can pose a potential risk. 

Methane causes danger of injury or death in several ways, including:

*Combustion: Methane is highly flammable – even small amounts present in the air can quickly ignite. Fire onboard can quickly spread and become difficult to contain, especially if methane or other flammable gases are present in the vicinity. 

*Illness: People exposed to high levels of methane can suffer from various symptoms, including mood changes, slurred speech, memory loss, blurred vision, nausea, vomiting and headaches.

*Injury: Liquified methane released under pressure (commonly used ) can cause frostbite if it comes into contact with the skin.

*Death: In rare circumstances when the concentration of methane in the air is incredibly high, fatalities can occur.

As with all gases, the risks associated with an undetected leak can increase ten-fold in a marine environment due to the isolation and confined spaces sea-going vessels naturally bring. Therefore appropriate management and a robust fixed gas detection system onboard are key. 


In order to safely and effectively manage methane in a marine environment, the installation and implementation of gas detection solutions are paramount. Although best-practice techniques can help to prevent leaks, the possibility of a breach even when all regulations are perfectly followed remains. Gases are unpredictable, as is day-to-day life at sea. Therefore high-performance, reliable gas detections worn on the person and stationed at static locations around each vessel are crucial to maintain the safety and security of all on board. 

Securing reliable gas detection support to keep your crew safe

Through robust gas detection solutions, the threat of methane on board can be greatly minimised. At Martek Marine, we specialise in reliable, specialised gas detection for the shipping industry, fully compliant with IMO SOLAS regulations. Keep your crews safe at all times with our cutting-edge gas detection technology, trusted worldwide. 

For more information on our range of fixed and portable gas detection please contact us today.