What is a Confined Space?

Confined Space Definitions

• A confined space is an area large enough to fully enter or perform certain jobs, with limited or restricted means of entry or exit, and is not designed for continuous occupancy (OSHA).
• NIOSH defines a confined space as a space with limited openings for entry and exit, unfavorable natural ventilation, and is not intended for continuous worker occupancy.
• The HSE (UK) defines a confined space as a substantially enclosed area where serious injury can occur from substances or conditions within the space or nearby.
• CCOHS (Canada) defines a confined space as a fully or partially enclosed space that is not designed or intended for continuous human occupancy, with limited or restricted entrance or exit, and can complicate emergency response activities.
• WorkSafeBC (Canada) defines a confined space as an enclosed or partially enclosed area that is big enough for a worker to enter, but not designed for regular occupation.

Key Characteristics

• Limited or restricted means of entry or exit
• Not designed for continuous occupancy
• Unfavorable natural ventilation (NIOSH)
• Potential for serious injury from substances or conditions within the space or nearby (HSE)
• Can complicate emergency response activities (CCOHS)

Permit-Required Confined Space

• A permit-required confined space, also known as a "permit space", contains or has the potential to contain a hazardous atmosphere or other serious safety or health hazards.
• Characterized as a high-risk workplace, requiring regulatory permits and strict entry and safety procedures.

OSHA Standard and Requirements

• OSHA 1910.146 is the standard for confined spaces.
• Found in Title 29 (Labor) Subtitle B (Regulations Relating to Labor) Part 1910 (Occupational Safety and Health Standards) Subpart J (General Environmental Controls).