Confined space

A work area that is not meant for human habitation with limited access and egress where there is a potential risk is known as a confined space. A confined space can be any enclosed space where there is a risk of death or serious injury from hazardous substances or dangerous conditions (e.g., lack of oxygen). You must understand the hazards and safety precautions for working in confined spaces.

Some examples of confined spaces that are fairly easy to identify include:

• storage tanks, silos, vessels, and vats
• manholes, sewers, and ductwork
• combustion chambers in furnaces, etc.
• unventilated or poorly ventilated rooms

Some places must be assessed at their location as confined spaces. It is not possible to provide a comprehensive detailed list of confined spaces, though many of the dangers associated with confined spaces are listed below:

• A lack of oxygen can occur due to a process or reaction.
• Poisonous gas, fumes, or vapour can build up in sewers and manholes or enter tanks and vessels from connecting pipes.
• Liquids and solids can suddenly fill the space.
• Free-flowing solids such as grain can form a solid section and then suddenly collapse.
• Flammable vapours or residues left in tanks or vessels can explode or catch fire.
• Dust may be present in high concentrations in flour or grain silos.
• Hot conditions can lead to a dangerous increase in body temperature.