Confined Space

What is a Confined Space?

Although they are not necessarily intended for people, many workplaces contain areas that are referred to as "confined spaces" because they are large enough for workers to enter and perform certain tasks. Additionally, a confined space is not intended for continuous occupancy and has limited or restricted entry and exit options. Tanks, vessels, silos, storage bins, hoppers, vaults, pits, manholes, tunnels, equipment housings, ductwork, pipelines, and others are examples of enclosed spaces.

Nearly every workplace has restricted areas. Underground or above-ground confinements are options. Despite its name, a confined space is not always small. Silos, hoppers, vats, utility vaults, tanks, water supply towers, sewers, pipes, access shafts, truck or rail tank cars, aircraft wings, boilers, manholes, pump stations, digesters, manure pits, and storage bins are all examples of confined spaces. Even though they still have "blue sky" above them, ditches, wells, and trenches may also be confined spaces when access or egress is restricted. Additionally, fish holds, shipping containers, and barges are thought to be potential confined spaces.

Examples of Confined Spaces

• Manholes
• Sewers
• Storage tanks
• Excavations
• Trenches
• Tunnels
• Lift and access shafts.
• Ducts
• Pipes
• Chambers
• Silos
• Hoppers
• Wells
• Unventilated areas and rooms

Hazards in Confined Spaces

• Poor air quality
• Chemical exposures
• Fire hazard
• Physical hazards
• Safety hazards
• Vehicular and pedestrian traffic.
• Shifting or collapse
• Visibility
• Biological hazards 

How do we control Hazards in Confined Spaces?

Through a risk assessment, the hazards and risks of a confined space must first be identified. A program for hazard control can be implemented after this is finished. In regular workplaces, the hierarchy of controls-based traditional hazard control methods can be effective in confined spaces. Elimination and substitution are the most effective controls; engineering controls should be considered if these are not feasible or if there is still risk. In addition to the other controls, administrative controls ought to be implemented. Personal protective equipment is the final option to take into consideration.

However, depending on the hazard and the confined space, special precautions that are not typically required at a typical worksite may also be required. Substitution replaces a hazard with a safer one (for example, using cold work methods instead of hot work) and elimination removes the risk (for example, finding another way to finish a job without entering a confined space). Mechanical ventilation is a common engineering control used in tight spaces. An example of a confined-space administrative control is the entry permit system. Equipment for protecting one's self, such as gloves, hearing protection, and respirators is also frequently used in tight spaces. However, wearing PPE may occasionally result in increased heat and mobility loss. Those circumstances require careful consideration. Always use PPE as part of a PPE program, and evaluate all potential risks and hazards associated with PPE use.