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.