According to 29 CFR 1910.146, a confined space is characterized by the simultaneous existence of three conditions:
- It must be large enough and so configured that it is possible for a person to bodily enter and perform work
- It has limited or restricted means of entry and exit
- It is not designed for continuous employee occupancy
Confined spaces include everything from railroad tank cars, to sewers, boilers, open topped pits, aircraft wing tanks, fuel storage tanks, vaults, manholes, elevator pits, and many other common workplace environments.
Just because a space meets the basic confined space definition, however, doesn’t automatically trigger any special workplace procedures beyond those for similar activities undertaken in any other non-confined space environments. Non-permit confined spaces are by definition not associated with any additional serious safety hazards (learn more in Confined Spaces: Standards and Guidelines to Know).