Introduction

1. The space is large enough and configured such that an employee can bodily enter and perform work; and
2. The space has limited means of entry (access) and exit (egress). This means that you need to use your hands or contort your body to enter the space. and
3. The space is not designed for continuous employee occupancy.

1. It is a fully or partially enclosed space, and
2. It is not both designed and constructed for continuous human occupancy, and
3. It is a space in which atmospheric hazards may occur because of its construction, location or contents or because of work that is done in it.

• In the United States, a confined space must be large enough for bodily entry. In Canada, the size of the space doesn't matter. Therefore we may assume it must be large enough for part of the body, like the head, to enter. Actually workers have been killed in confined space after only sticking there heads through a hatch or lid. Workers have also been killed in rather shallow trenches. To have a fatal confined space accident, all it takes is a trench or ditch a couple of feet (or a meter) in depth, some heavier-than-air hazardous atmosphere.
• To be considered a confined space in the United States, the space must have limited access or egress. There is no such requirement in Canada. Examples of limited access are hatches or covers.
• In both the U.S. and Canada, a confined space must not be designed for human/employee occupancy.
• And finally, in Canada the space must have the potential for developing a hazardous atmosphere. In the United States, this requirement is not included in the definition.

1. Contains or has the potential to contain a hazardous atmosphere; or
2. Contains a material with the potential to engulf someone who enters the space; or
3. Has an internal configuration that might cause an entrant to be trapped or asphyxiated by inwardly converging walls or by a floor that slopes downward and tapers to a smaller cross section; or
4. Contains any other recognized serious safety or health hazards.

• Open-topped Spaces with and deep spaces narrow openings
• Pits Ship compartments
• Wells Silos
• Vats Pipes
• Hoppers Tunnels
• Bins Tanks
• Degreasers Casings
• Kettles Sewers

Confined spaces are found not only in industrial settings but also in public places such as shopping malls and large public swimming pools. Waterfalls and water fountain displays used in malls for beautification may have pump vaults or valve pits that are seldom entered. Some swimming pool pumps are placed in vaults below ground. There have been reports of maintenance employees entering these areas and losing consciousness. Take a look at this discussion that includes examples of where confined spaces are found in construction...

• Space configurations such as small openings and inwardly converging walls, which can trap an entrant, restrict easy entry and exit, or impede rescue.
• Atmospheric hazards such as gasoline tank vapors, combined with limited ventilation. Such conditions can cause asphyxiation or explosion.
• Physical hazards, such as unstable grain contained in silos, which can engulf a worker.
• All other serious hazards associated with general industry, such as electrical equipment, moving machinery, falling objects, and wet or slippery surfaces.

• No ventilation (pits and vaults seldom opened).
• Leaking chlorine gas (which is heavier than air) can accumulate in low-lying spaces.
• Oxygen depletion can be caused by:
• Rotting vegetation and decaying dead animals.
• Corroding or rusting machinery.

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