Confined spaces are:

• Large enough (and so configured) that an employee can bodily enter and perform assigned work
• Limited or restricted for entry or exit (e.g. tanks, vessels, silos, storage bins, hoppers, vaults, and pits)
• Not designed for continuous employee occupancy

Note that all three conditions must be present for a space to be considered a confined space.

Permit-required confined spaces (permit spaces) have at least one of the following characteristics:

• Contain, or have the potential to contain, a hazardous atmosphere
• Contain a material that has a potential for engulfing an entrant
• Have an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls, or by a floor that slopes downward and tapers to a smaller cross section
• Contain any other recognized serious safety or health hazard

Note that if any of the above characteristics is present, the space shall be classified as a permit-required confined space.

All employees who will enter permit-required confined spaces (including entrants, attendants, and supervisors) shall receive training in confined space procedures. Training must occur:

• Before assignment to confined space operations
• When duties change
• When a new hazard is present
• When entry procedures change

These and other pertinent definitions are included in the Cal/OSHA Confined Spaces Regulations.

Stanford provides confined space guidance to:

• Prevent employee injury, illness, or death resulting from confined space and permit-required confined space operations
• Define a confined space and permit-required confined space
• Identify hazards commonly associated with permit-required confined space entry and rescue
• Train Stanford University employees who will enter confined spaces
• Maintain records
• Comply with the OSHA regulatory requirements for confined spaces

The Confined Space Program shall conform to Cal/OSHA requirements, which requires a written program. Where the word “shall” is used in this subtopic, requirements are mandatory by regulation.