Confined space entry
Tanks, pits and vessels: atmosphere, isolation and engulfment hazards controlled by permits, gas testing and standby rescue.
4 threats 13 barriers 3 consequences safety-critical barriers marked
Use this template free. Copy “Confined space entry” into your own workspace and adapt every barrier — no credit card.
Start free with this template →Threats & preventive barriers
Each threat is a credible pathway to the top event; its barriers interrupt that pathway before control is lost.
Oxygen deficiency or toxic atmosphere
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Pre-entry gas testing ★ critical
Socio-technical · 90% effective · Owner: Authorised Gas Tester
📅 Gas detector calibration · monthly keep-alive task
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Continuous atmosphere monitoring ★ critical
Continuous · 85% effective · Owner: Entry Supervisor
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Forced ventilation during work
Active hardware · 80% effective · Owner: Site Supervisor
Hazardous energy or media entering the space
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Isolation & lock-out/tag-out with blinding ★ critical
Socio-technical · 90% effective · Owner: Permit Authority
Complex line-ups misidentify isolation points
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Permit to work with entry register
Socio-technical · 85% effective · Owner: Permit Authority
Hot work inside the space
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Hot-work permit with fire watch
Socio-technical · 80% effective · Owner: Permit Authority
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Local exhaust extraction
Active hardware · 75% effective · Owner: Site Supervisor
Engulfment by stored material
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Emptying & cleaning before entry
Socio-technical · 85% effective · Owner: Operations Lead
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No-entry-under-bridged-material rule
Behavioural (human) · 70% effective · Owner: Entry Supervisor
Consequences & recovery barriers
Once the top event happens, recovery barriers limit each consequence.
Asphyxiation fatality
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Standby person with rescue equipment ★ critical
Behavioural (human) · 80% effective · Owner: Entry Supervisor
📅 Confined-space rescue drill · semiannual keep-alive task
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Retrieval harness & tripod
Passive (hardware) · 80% effective · Owner: Site Supervisor
Multiple casualties (would-be rescuers)
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No-entry rescue rule & SCBA for rescuers ★ critical
Behavioural (human) · 75% effective · Owner: Emergency Coordinator
Delayed medical response
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Site emergency response plan
Socio-technical · 75% effective · Owner: Emergency Coordinator
Copying this template gives you a fully editable bowtie: barrier owners arrive as role suggestions, escalation factors sit on their barriers, and keep-alive activities are scheduled from the moment you copy. New to the notation? Read what the bowtie method is or browse the practical guides.
Use this template free. Copy “Confined space entry” into your own workspace and adapt every barrier — no credit card.
Start free with this template →