Accidents often occur in confined spaces because workers were unaware that they were in such an area to begin with. As such, the first step toward safety in and around confined spaces is to identify them.
Confined Space Characteristics
OSHA standards define confined spaces as meeting the three following criteria:
- The space is large enough for an employee to enter.
- The space has limited means of entry. This requirement is sometimes misunderstood as meaning that the space has only one entrance and exit, but it actually refers to the physical ease with which workers can get in and out. Needing a ladder or having to duck under a low doorway are examples of limited means of entry and exit.
- The space is not designed for continuous occupancy, such as due to a lack of ventilation, lighting or sufficient room to work and move around.
Common areas of a job site that may meet the requirements to be considered confined spaces include:
- Manholes
- Sewers
- Storm drains
- Water mains
- Lift stations
- Tanks
- Basements without steps
- Attics
- Vessels
Confined Spaces and Permits
Permit-required confined spaces are areas in which employers must take extra steps to protect workers. Confined spaces are considered permit-required if the area has one or more of the following four additional hazards:
- The confined space has a hazardous atmosphere, such as:
- Oxygen deficient—Concentration less than 19.5%
- Oxygen enriched—Concentration greater than 23.5%
- Flammable—Gas, vapor or mist greater than 10% of its lower explosive limit, or airborne combustible dust at a concentration greater than or equal to its lower explosive limit
- Toxic gas—Carbon monoxide or other hazards that can cause death, incapacitation or impairment
- The confined space contains material that could engulf an occupant, such as water or sand.
- The confined space is configured in a way that an occupant could be trapped or suffocated by inwardly converging walls.
- The confined space contains any other serious safety hazards, such as moving parts, venomous pests or extreme temperatures.
Evaluating Confined Spaces on Job Sites
Job site areas that may meet the qualifications to be considered a confined space must be evaluated by a qualified person. That person should also inspect the space to determine whether it requires a permit.
Make your safety a priority.
