Permit to Work System
A Permit to Work is the documented method by which the SMS controls high-risk work under the applicable procedure and risk assessment.
Operational Explanation
A Permit to Work is a documented method adopted by the SMS to control high-risk work. ISM §7 requires procedures for key operations but does not prescribe one PTW model, seven categories, or universal thresholds and durations.
Regulatory Reference
ISM Code §7: the Company establishes procedures, plans and instructions for key operations. Categories, atmospheric limits, signatories and validity derive from risk assessment, SMS and applicable sector guidance. SOLAS III/19.3.6 concerns entry and rescue drills, not the source of an enclosed-space permit.
Scope of Application
Work subjected by the ship's SMS to PTW control according to risk, ship, cargo, location and applicable guidance; there is no uniform IMO list of seven permits.
Procedure / How to Complete It
- Identify the work and applicable SMS procedure.
- Apply thresholds, signatories, validity, isolation and monitoring required by company procedure and relevant guidance.
- Suspend and reassess when conditions, people or scope change.
- Close the permit and restore the system under the procedure.
Practical Example
Example: for hot work, atmospheric limits, signatories, fire watch and validity are taken from the SMS procedure and applicable guidance; the permit is suspended if conditions change.
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Hot work permit renewed without a new atmosphere test if the work extends beyond the initial validity | Risk conditions not updated, possible accident with an atmosphere that has changed in the meantime | Always repeat the atmosphere test when renewing a hot work permit |
| Multiple permits active at the same time without checking their mutual interactions | Unforeseen risk combinations (e.g. hot work and bunkering in the same area) | Always check all active permits before authorising a new one |
| Cold work treated as non-hazardous and therefore not subject to a formal permit | Activities with real risks (e.g. painting in a confined space) carried out without adequate controls | Apply the PTW system to cold work in hazardous areas too, not only to hot work |
What the PSCO Checks
Operational Tips
- Always repeat the atmosphere test when renewing a hot work permit, don't rely on the initial test.
- Always check the interaction between all active permits before authorising a new one.
- Apply the PTW system to cold work in hazardous areas too, don't automatically treat it as low risk.
Preparation checklist
- SMS procedure and risk identified
- Thresholds and signatories taken from applicable source
- Validity and reassessment defined
- Isolation and monitoring checked
- Close-out and restoration documented
FAQ
Related Topics
Editorial revision of 9 August 2026 · page fingerprint b274e063e945