OSHA 1910.147 Explained

OSHA  1910.147 - This standard covers the maintenance and servicing of machinery and electrical equipment in which the unexpected energization or start up of the machines or equipment, or release of stored energy, could harm employees. This standard establishes minimum performance requirements for the control of such hazardous energy.

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In accordance with osha standard 1910.147, all equipment, machines and processes shall be locked out prior to servicing. Lockout procedures are posted in the operating area and/or by the main energy source of each machine.

The Occupational Safety and Health Administration (OSHA) Standard 1910.147, more commonly known as lockout tagout, is inplace to protect front line electrical workers from the uncontrolled or unanticipated re-energization of electrical machines and/or equipment which results in the sudden release of stored electricity during maintenance or service. The standard mandates that when workers are serving a piece of equipment, they should turn the equipment off and lockout and/or tagout the ignition mechanism to prevent the equipment from starting up until such time that the work is complete and the worker is no longer exposed to potential danger.

1910.147 is a generally easily understood. However, it is one of OSHA’s most-cited violations every year. This article explains why industry needs the control of hazardous energy (lockout/tagout) standard, and covers the standard in detail and offer suggestions to help your company has an effective  lockout tagout program. 

“LOTO” is a technique used to prevent energy from being released during the servicing of equipment.  This is accomplished by placing locks on energy isolation devices prior to starting work.

  • Chemical
  • Electrical
  • Hydraulic
  • Mechanical
  • Thermal
  • Pneumatic


As low as 30 volts can carry enough current to kill

  • Use non-conducting tools
  • Discharge all capacitors afetr lockout
  • Ensure all control power is de-energized
  • Lock & tag source breakers not switches
  • Stored potential energy can be released during work causing injury or death
  • Check circuts dead before working

What you need for loto

  • Written loto schedule
  • Locks & tags-identified for the worker
  • Hasps-for placing locks & tags
  • Breaker clips-for electrical loto
  • Blank flanges-for fluid lines
  • Valve covers-for loto of valves
  • Plug buckets-for electrical plugs



Only the employee who placed the tag “or” a supervisor, after obtaining permission from the worker who placed the tag 

Each person working on the equipment must place their own locks & tags to ensure their safety, even if the equipment already has a lock & tag on it.



If servicing lasts more than one shift, lockout/tagout protection must not be interrupted.

When the employee who applied device is not there to remove it, it can be removed only in an emergency and only under the direction of the supervisor.


  • Adjusting
  • Inspecting
  • Modifying
  • Replacing parts
  • Clearing jams
  • Lubricating
  • Cleaning
  • Tool changes



Energy Isolating Device - A mechanical device that physically prevents the transmission or release of energy.

Energy Control Procedure - Safety program adopted by the employer that includes energy control procedures plus provisions for inspecting the procedures and training employees for lockout/tagout.

Authorized Employee - one who locks out machines or equipment in order to perform the servicing or maintenance on that machine or equipment.

Affected Employee - one whose job requires him/her to operate or use a machine or equipment on which servicing or maintenance is being performed under lockout, or whose job requires him/her to work in an area in which such servicing or maintenance is being performed.


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