20 FEATURE
Odourless, colourless, dangerous: The hidden danger of methane gas
By
Megan O’ Connor, with technical information from Chris Coetzee( OHSS Consulting) and Geoff Snelling
In this feature article, we talk about everything methane – why it is dangerous, how to correctly handle an environment with methane gas, as well as the training available for methane gas in South Africa.
A recent tragedy in the Vaal Triangle has once again highlighted the tragic, and sometimes fatal, results of methane gas exposure. In this particular incident, three plumbers were called to inspect a municipal drain line. The first plumber opened the drain, climbed onto his hands and knees to inspect the drain, and was then fatally hit by the gas, falling into the drain. His colleague, seeing the incident, heroically jumped into the drain to try and save him, but also tragically lost his life. The third plumber, and supervisor of the incident, was successfully resuscitated after approaching the drain.
The danger of methane gas is no new information – we’ ve all seen the headlines:
‘ Tragic end for three Ekurhuleni plumbers overcome by methane in Benoni manhole’ – Satori News, 30 October 2024.
‘ Joburg sanitation worker dies from methane gas exposure’ – The Citizen, 7 January 2025.
‘ Methane gas caused Joburg explosion’ – News24, 2 August 2023.
But why exactly is the gas so dangerous?
Methane gas Methane gas, in confined spaces, reduces oxygen levels and can bring them very low – increasing chances of asphyxiation. Similarly, because the gas is lighter than air, oxygen can be displaced, causing rapid oxygen loss while breathing. Methane is highly explosive and highly flammable, so welding and soldering in an environment with methane can easily ignite the gas.
Environments where the gas is most likely to be encountered by plumber are confined spaces, including:
• Pump stations
• Deep sewer manholes
• Certain crawl spaces under suspended flooring
• Storm water drains and parking areas in big cities
Making the gas even more dangerous is its invisibility – you cannot see it, you cannot smell it and you cannot taste it. This means that the only way to protect yourself from the gas is with the correct safety equipment.
The biggest misconception about methane is believing that you can rely on your senses. You may walk in and think:
•“ It smells fine”
•“ It feels fine”
•“ I’ m not getting lightheaded, so I’ m okay”
But with methane:
• You don’ t always smell the buildup
• You can’ t smell oxygen deficiency
• It can feel fine initially, but over an extended period it may become unsafe
TIP: Snelling posits that one sign there may be methane gas in your work space is if there are no cockroaches, or no sign of insect or rodent life in the space.
www. plumbingafrica. co. za @ plumbingonline @ plumbingonline @ PlumbingAfricaOnline July 2026 Volume 32 I Number 05