Confined Space Classification Wizard
Confined Space Criteria
1. Is the space large enough for a worker to bodily enter?
2. Does the space have limited or restricted means of entry or exit?
3. Is the space NOT designed for continuous human occupancy?
Hazard Assessment
4. Contains or has potential for hazardous atmosphere?
5. Contains material that could engulf an entrant?
6. Has converging walls or inwardly sloping floors?
7. Contains any other recognized serious safety/health hazard?
Classification
Confined Space (Non-Permit)
Required Procedures
- Develop and implement written confined space program.
- Train all entrants on confined space hazards.
- Monitor atmosphere before and during entry.
- Ensure adequate ventilation.
- Maintain communication with entrants.
PPE Requirements
- Hard hat.
- Safety glasses.
- Appropriate footwear.
- Atmospheric monitor (4-gas minimum).
Documentation Requirements
- Written confined space program.
- Training records for all entrants.
- Atmospheric monitoring records.
Decision Path
| Question | Answer | Result |
|---|---|---|
| Is the space large enough for a worker to bodily enter? | Yes | Proceed to next question |
| Does the space have limited or restricted means of entry or exit? | Yes | Proceed to next question |
| Is the space NOT designed for continuous human occupancy? | Yes | This IS a confined space |
| Does the space contain or have potential for a hazardous atmosphere? | No | No atmospheric hazard |
| Does the space contain material that could engulf an entrant? | No | No engulfment hazard |
| Does the space have converging walls or inwardly sloping floors? | No | No converging walls |
| Does the space contain any other recognized serious safety or health hazard? | No | No other serious hazards |
This confined space wizard walks you through the OSHA decision tree to classify a space as not a confined space, a non-permit confined space, or a permit-required confined space (PRCS). It asks a fixed sequence of yes/no questions about access, occupancy, and hazards, then returns the classification along with the required procedures, documentation, entry-permit elements, and PPE. Because it has no numeric formula, it is a logic tool rather than an arithmetic calculator.
How it works
- Answer the three confined-space gate questions: is the space large enough to bodily enter, does it have limited or restricted entry/exit, and is it not designed for continuous occupancy. All three must be true for the space to be a confined space; a single "no" ends the assessment as "not a confined space".
- If it qualifies as a confined space, answer four hazard questions covering hazardous atmosphere, engulfment, converging walls or sloping floors, and any other recognized serious hazard. Any single "yes" escalates the space to permit-required.
- Read the classification result and the generated checklists — required procedures, documentation, entry-permit contents, and PPE — which scale from a basic written program for a non-permit space up to a full PRCS program with entry supervisor, attendant, atmospheric monitoring, and rescue capability.
Worked example
A worker must enter a below-grade storage tank that is big enough to climb into, has only a top manway for access, is not meant for continuous occupancy, and may contain residual solvent vapors.
- Gate questions: large enough to enter = yes, limited entry/exit = yes, not for continuous occupancy = yes → the space is a confined space.
- Hazard questions: potential hazardous atmosphere = yes (residual solvent vapors), engulfment = no, converging walls = no, other serious hazard = no.
- Because at least one hazard is present, the space escalates to permit-required.
Classification: Permit-Required Confined Space (PRCS). A written PRCS program, entry permit, continuous atmospheric monitoring, designated attendant, and rescue capability are required before entry.
Frequently asked questions
- What three criteria define a confined space under OSHA?
- A space is confined if it is large enough for a worker to bodily enter and perform work, has limited or restricted means of entry or exit, and is not designed for continuous human occupancy. All three must be met; failing any one means it is not a confined space.
- What turns a confined space into a permit-required confined space?
- Any one of four conditions: a hazardous or potentially hazardous atmosphere, a material that could engulf an entrant, an internal configuration such as converging walls or inwardly sloping floors that could trap or asphyxiate, or any other recognized serious safety or health hazard.
- Is this tool a substitute for a formal site assessment?
- No. It applies the standard OSHA classification logic to the answers you provide, but a qualified person must perform the actual hazard evaluation, atmospheric testing, and program development. Use the output as a planning checklist, not as the official determination.
- How long must entry permits be retained for a PRCS?
- Under the permit-required confined space program, completed entry permits must be retained for at least one year to support program review. The calculator lists this along with training records, monitoring logs, and rescue documentation in the PRCS output.