Most people think of a confined space as a small tunnel or tank that is cramped and tight to work in. And they wouldn’t be wrong. But when it comes to potential gas hazards and oxygen depletion, you could be surprised by what actually constitutes a confined space and you could potentially be at risk without even realising it.
The HSE defines a confined space as “A place which is substantially enclosed (though not always entirely), and where serious injury can occur from hazardous substances or conditions within the space or nearby (e.g lack of oxygen)”. Examples of confined spaces are sewers, enclosed drains, silos, storage containers, open-topped chambers or even unventilated or poorly ventilated rooms.
The dangers of working in such conditions are from a build-up of poisonous gasses, fumes and vapours, fires and explosions from flammable gasses and a build-up of oxygen or residues left on surfaces which can give off gas, fumes or vapours.
And it’s not just the hazards that are lurking in the confined space that are a danger, but also the work that is carried out whilst in the confined space. It can even be as simple as cleaning out an unventilated cupboard with an ammonia-based product.
Any work that is to be carried out in a confined space requires a risk assessment to assess the potential hazards and to formulate a plan for safe entry and works. Part of this plan will require the air to be tested prior to entry with the use of a gas detector. The gas detector must be correctly calibrated and bump tested before use. Where conditions within the confined space can change, continuous monitoring of the air must take place and this will require the person or persons to wear portable gas detectors as part of their protective equipment.