What does this activity involve?
Lockout Tagout protects workers from unexpected startup, energization or release of stored energy. Every hazardous energy source must be identified, isolated, locked, tagged, released and verified before work begins.
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Hazard Control
Lockout Tagout Safety
Essential guidance for controlling hazardous energy during servicing, maintenance, inspection and equipment intervention.
Independent HSE guide10 min readHigh Risk
SERNEM • Quick Technical Reference
Lockout Tagout Safety: essential answers
These answers summarize this guide; they do not replace a work permit, legal compliance decision or site-specific risk assessment.
What are the main hazards?
- • Unexpected equipment startup
- • Electrical shock or arc flash
- • Release of hydraulic or pneumatic pressure
- • Movement caused by gravity
See the full hazard list below.
What are the essential controls?
- • Identify every hazardous energy source before shutdown.
- • Notify affected employees before applying lockout.
- • Shut down equipment using the normal stopping procedure.
- • Isolate electrical, mechanical, hydraulic, pneumatic, thermal, chemical and gravitational energy sources.
The full control measures are listed below.
What should be checked before work?
- ✓ The equipment and scope of work are clearly identified
- ✓ All hazardous energy sources have been listed
- ✓ Affected employees have been notified
- ✓ The equipment has been shut down normally
- ✓ All isolation points have been locked and tagged
- ✓ Stored energy has been released or restrained
The complete checklist appears further down this page.
Overview
Lockout Tagout protects workers from unexpected startup, energization or release of stored energy. Every hazardous energy source must be identified, isolated, locked, tagged, released and verified before work begins.
Main Hazards
- • Unexpected equipment startup
- • Electrical shock or arc flash
- • Release of hydraulic or pneumatic pressure
- • Movement caused by gravity
- • Release of stored mechanical energy
- • Thermal energy and hot surfaces
- • Chemical or process product release
- • Incorrect or incomplete isolation
Required PPE
- ✓Safety helmet
- ✓Safety glasses
- ✓Task-specific gloves
- ✓Safety footwear
- ✓Arc-rated PPE where electrical risk exists
- ✓Face protection where pressure release is possible
Essential Controls
- 1Identify every hazardous energy source before shutdown.
- 2Notify affected employees before applying lockout.
- 3Shut down equipment using the normal stopping procedure.
- 4Isolate electrical, mechanical, hydraulic, pneumatic, thermal, chemical and gravitational energy sources.
- 5Apply personal locks and identification tags to each isolation point.
- 6Release, block or restrain all stored and residual energy.
- 7Verify zero-energy condition using appropriate testing methods.
- 8Attempt a controlled start or try-out where safe and applicable.
- 9Use group lockout procedures when multiple workers are involved.
- 10Remove locks only under an approved and controlled removal procedure.
Common Mistakes
- ×Locking only the main electrical switch
- ×Failing to identify stored or residual energy
- ×Using another worker's lock
- ×Relying only on stop buttons or control circuits
- ×Skipping zero-energy verification
- ×Removing a lock without authorization
- ×Using one lock for multiple workers
- ×Starting work before all isolation points are secured
Pre-work Checklist
- ✓The equipment and scope of work are clearly identified
- ✓All hazardous energy sources have been listed
- ✓Affected employees have been notified
- ✓The equipment has been shut down normally
- ✓All isolation points have been locked and tagged
- ✓Stored energy has been released or restrained
- ✓Zero-energy condition has been verified
- ✓Group lockout controls are in place where required
- ✓The work area is safe to enter
- ✓Restart authorization responsibilities are understood
Unexpected Energy or Lock Removal
Stop work immediately if an unidentified energy source, pressure, movement or unsafe condition is discovered. Do not remove another person's lock unless the formal lock-removal procedure is authorized, documented and fully controlled.
Technical References
OSHA links lead to official US regulations. Always confirm local legal requirements, scope of applicability, and site-specific procedures. Other listed sources remain informational references until their official links are verified.
Related Guides
SERNEM Workflow
Use this guide in the field
Continue with the matching inspection, toolbox talk and poster for the same topic.
Safety Pack
Open full pack →🔒 LOTO / Energy Isolation
Guide + toolbox + inspection + poster + risk assessment + Method Statement + signs.
Field Inspection
Lockout Tagout Safety Checklist
Turn the guide controls into a field-verifiable inspection.
Open →Toolbox TalkLOCKOUT TAGOUT TOOLBOX TALK
Brief the team with a field-ready toolbox talk on the same topic.
Open →Field PosterLOTO Golden Rules
Reinforce the critical rules with a visible field poster.
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