Hazardous Energy Lock Out / Tag Out

Safe practices require that lock out/tag out procedures be followed when working on electrical and mechanical equipment. Lock out devices and tags are intended to protect the employees who may be working on the systems being shut down. They are not to be used to discourage tampering, to prevent unauthorized operation, or for other purposes.

Lock Out / Tag Out Procedures

  • Document specific energy control procedures for the piece of equipment you need to service, using the Equipment-Specific Lockout/Tagout Procedure Template.


  • When a circuit must be opened for repairs, alterations, or examinations, immediately lock it, block it open, or remove all fuses.
  • Attach "DANGER - DO NOT OPERATE" tags to all open devices. Sign and date the tags, stating the reason for the disconnect.
  • Put your own lock on the open disconnect. Use multiple locking devices where necessary.
  • When it is not possible to install a lock, secure the circuit by another practical and safe means and attach a completed tag.
  • Switches that open only the control circuit (e.g., "lock-stop stations") are not positive disconnects and shall not be used for lock out protection.
  • Use a voltage tester to check all electrical circuits. Ensure the tester is operational.
  • Do not close an open disconnect unless absolutely certain that it is safe to do so, even if no tag has been attached.
  • Immediately report to your supervisor any equipment that does not have proper and safe disconnecting means. (The plug and receptacle of cord-connected equipment constitute adequate disconnecting means.)
  • Do not remove another person's lock. See your supervisor.
  • Contractors shall furnish and use their own locks.


  • Bleed down steam, air, or hydraulic cylinders.
  • Block valves with a locking device. Attach "DANGER" tag, sign it, date it, and state the reason for the isolation.
  • Block gears, dies, and other mechanisms.
  • Release coiled springs, spring loaded devices, and securing cams.
  • Put blocks under equipment which might descend, slide, or fall.
  • Put blocks or stands under raised vehicles and equipment to protect against failure of hoists, jacks, or elevating equipment.

(Printable PDF version of these safe practices)

Code of Safe Practices are prepared by SSU Dept. of Environmental Health and Safety.