Types of Confined Spaces and their Hazards

Confined spaces are not like any other ordinary workplace, and being within them can cause injuries and fatalities. The Canadian Centre for Occupational Health and Safety notes that precautions must be made to make confined spaces safe before workers enter. For the workers who brave the hazardous conditions of confined spaces, it’s vital to know just what sort of risks could be faced.


What are confined spaces?

A confined space is any enclosed space that carries with it a risk of death or serious injury from dangerous conditions or hazardous materials. These are areas that are not designed or purposed for human occupancy. Confined spaces generally have restricted entrances and exits, and despite their name, they’re not necessarily small.

Types of confined spaces

Confined spaces can exist both above and below ground. Some examples of confined spaces include:

  • Storage tanks and digesters
  • Sewers
  • Silos
  • Vats
  • Pipes
  • Wells
  • Tunnels
  • Ship holds
  • Subcellars
  • Cold storage rooms
  • Ducts
  • Access shafts
  • Manholes

A full list is difficult to provide, because some spaces that you may not consider hazardous can become confined spaces when work is being carried out within them, or during construction. Depending on the particular environment of a confined space, workers may be faced with one or a combination of hazards.

Lack of oxygen

Certain soils can react with oxygen in the air, thereby reducing the amount of oxygen available for workers operating within the confined space. Groundwater mixed with chalk and limestone can also produce carbon dioxide and displace breathable air.

Within the hold of a ship or a freight container, the cargo on board can react with air inside the space and reduce the amount of oxygen. Rust that forms within steel containers and tanks can also impact the amount of clean air available for workers.

Hazardous gases

Dangerous gases, fumes, and vapour can build up within sewers and manholes because of the variety of contaminants present. Pipework that contains these contaminants can also move poisonous gases into connected tanks or vessels. Gases may also leak into ditches and pits from contaminated land such as landfills and oil fields.

Welding activities or the use of volatile solvents and adhesives can also emit dangerous gases into a confined space. Sometimes the residue from previously-used products will emit vapours as well.

Solids and liquids

Substances that can suddenly fill a confined space pose a risk to workers within. Solids that are free-flowing, like grain or flour, can sometimes partially solidify. When that happens, a blockage is formed that could collapse unexpectedly.

Heat and fire

Confined spaces may not have adequate ventilation, which can lead to heat buildup within the space, and dangerous increases in body temperature for workers. Sometimes increases in temperature may be the result of work being carried out within the space. Flammable materials and vapours that exist within some confined spaces also poses the risk of fire and explosions.

The hazards facing workers within confined spaces are real, and that’s why it’s important for employers to understand and mitigate the risks involved. That allows employers to get the best from their workers, while giving workers the ability to do their jobs safely.

Wessuc plans out each confined space entry to ensure the work is completed in the safest manner possible. All crew members receive the necessary confined space training which enables us to react quickly to any circumstances that may arise during a clean out project.

Contact us at info@wessuc.com to learn more about our trained professionals and how we can help you.

Posted in Confined Space.

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