Working in confined spaces has a reasonably foreseeable risk to workers of fire, explosion, loss of consciousness, asphyxiation or drowning. Confined spaces can be dangerous and leave little room for error. Learning about common mistakes made working in confined spaces can help you better prepare yourself before entering a confined space and will hopefully ensure you don’t make the same mistakes.

Confined workplace safety

Working in a confined space is dangerous because it exposes you to noxious fumes, reduced oxygen levels, or a risk of fire. You could also be at risk for flooding/drowning or asphyxiation from some other source such as dust, grain or other contaminant. Before deciding to work or carry out a job in a confined space, you should always ask your safety coordinator these questions:

  • Does the confined space have noxious fumes? If so, you should consider how these can be ventilated or removed.
  • Is there a risk of liquids or gases flooding in? If so, you should establish whether the valves can be locked shut.
  • If someone is going into a confined space and there is not enough oxygen to breathe properly, you must provide breathing apparatus or ventilate the space to increase oxygen levels before entering.

The dos and don’ts of working in a confined space


  • be aware of the risks that may occur within a confined space
  • make sure the person doing the work is capable and trained in both the work and the use of any emergency equipment


  • work in confined spaces unless it’s essential to do so
  • ignore the risks – just because a confined space is safe one day doesn’t mean it will always be
  • let others enter a confined space until you are sure it’s safe to do so