What Is a Confined Space? + Free Permit Template
A confined space is a work area that is large enough to enter but not designed for continuous occupancy, has limited means of entry or exit, and may contain atmospheric hazards, engulfment risks, or configuration hazards. OSHA regulates confined space entry under 29 CFR 1910.146 (General Industry) and 1926.1200 (Construction).
What Makes a Space "Confined"?
Per OSHA, a confined space has three characteristics: (1) Large enough for a worker to enter and perform work, (2) Limited or restricted means for entry or exit, and (3) Not designed for continuous occupancy.
Examples of Confined Spaces
- Tanks, vessels, and silos
- Manholes and vaults
- Pipelines and ducts
- Boilers and pressure vessels
- Trenches deeper than 4 feet
- Storage bins and hoppers
Permit-Required Confined Spaces (PRCS)
A permit-required confined space contains one or more hazards: hazardous atmosphere (toxic, flammable, O2 deficient), engulfment hazard, configuration hazard (converging walls, sloped floors), or other recognized serious hazards.
Entry Requirements
- Entry Permit: Written authorization with hazards identified
- Atmospheric Testing: O2, LEL, H2S, CO before and during entry
- Ventilation: Continuous fresh air supply
- Attendant: Trained person stationed outside space
- Rescue Plan: Non-entry rescue preferred (retrieval system)