In many confined spaces, the most dangerous element isn’t what you can see: it’s what you can’t.
Atmospheric hazards, such as oxygen deficiency, toxic gases, and flammable vapours, account for a majority of confined space fatalities worldwide. They are silent and invisible, striking before a worker realises what’s happening.
Understanding the Risk
Even if a confined space was safe the previous day, its atmosphere can change overnight. Common sources include:
- Oxygen depletion, caused by rusting metals, biological decay or displacement by other gases such as nitrogen or carbon dioxide.
- Toxic gases, such as hydrogen sulphide (H₂S), carbon monoxide (CO), or ammonia (NH₃), generated from chemical processes, natural decomposition of materials and work-related activities like welding or painting.
- Flammable vapours from fuels, paints, or cleaning agents.
The danger is that many of these gases are colourless and odourless, giving workers no natural warning. One deep breath can render someone unconscious. Worse still, rescue attempts often compound the tragedy when unprotected rescuers enter the same space.
Detection and Prevention
The first step to atmospheric safety is detection before any incidents can occur.
- Use portable gas detectors before and during entry to continuously monitor the air. Multi-gas detectors, such as the WatchGas SST range, provide real-time readings for O₂, CO, H₂S, and combustible gases.
- Ensure proper calibration of detectors using a docking system or calibration station to maintain accuracy. A tool is only as reliable as its accuracy, so constant checks are important.
- Implement constant ventilation to refresh the air inside and prevent accumulation of toxic and combustible gases.
- When gas levels are unsafe, do not enter without proper respiratory protection such as self-contained breathing apparatus (SCBA) or supplied-air respirators.
Solutions in Practice
United Resources offers integrated gas detection and respiratory safety solutions, including portable detectors, calibration gases, and supplied-air respirators for confined space operations. Together, they help ensure that no worker enters an unknown atmosphere unprotected.
Atmospheric hazards are invisible, but that doesn’t mean they’re unpredictable. With continuous monitoring, proper respiratory protection, and training, we can make confined space entries safer, smarter, and more controlled.
