When is Lockout Tagout procedure Necessary?

Lockout/tagout is used to protect workers from the unexpected re-energization of equipment. Hazardous energy sources are isolated during servicing in order to help prevent injury. For this purpose, special equipment is used, such as a safety padlocks, lockout boxes, lockout boards and others. However, it is sometimes difficult to determine when a machine must be locked out and when servicing can be safely accomplished without lockout.

When to Lockout a Machine

According to OSHA’s Control of Hazardous Energy regulation, a machine must be locked out any time one of the following conditions occur:

  • An employee must remove machine guarding.
  • An employee bypasses a guard, interlock, or other safety device.
  • An employee places part of their body in harm’s way.
  • An employee performs any major servicing or maintenance work.

What is Considered Servicing?

OSHA classifies many tasks as servicing activities, including the following:

  • Constructing or installing a new machine.
  • Setting up a machine to perform normal operation.
  • Renovating or modifying an existing unit.
    Repairing a machine.
  • Making machine adjustments or major tool changes.
  • Inspecting a machine for errors, jams, or other problems.
  • Cleaning inside the unit.
  • Clearing a jam or debris.
  • Lubricating parts inside the machine.
  • Any other maintenance or servicing tasks where the employee may be exposed to release of hazardous energy.

When Lockout May Not be Needed

Normal Operations
Work done during normal operation that is a part of the machine’s intended use is exempt from lockout/tagout. Servicing work done during normal operation is not exempt unless it falls under one of the following situations.

Plug Systems
Cord and plug equipment, where electrical energy is the only hazardous source and can be under the exclusive control of the employee is exempt. The electrical disconnect must be a plug located near enough to the equipment that it cannot be energized without the authorized employees knowledge.

Hot Tap Work
Hot tap operations may be exempt for lockout/tagout provided the employer can show that:

  • Continuity of the system is essential to plant operations;
  • Shutdown of the system is impractical, and; Other safety measures are used to provide additional protection to the employee(s).

Minor Servicing Activities
Minor servicing activities such as minor tool changes and adjustments, that take place during normal operating conditions, can be done without locking out the machine so long as:

  • The work is routine;
  • The task is repetitive, and;
  • The task is integral to the use and operation of the equipment.

Alternative safety measures should be taken to provide employees additional protection.

Partial Lockout/Tagout Procedures

Deviation from the written lockout/tagout procedure is strictly prohibited under OSHA’s Control of Hazardous Energy standard. Lockout/tagout procedures must also be written to fully de-energize the system and bring the machine to a zero-energy state.

Breaking Down Complex Machines

When developing lockout/tagout procedures for large, complex machinery, it may be necessary to create multiple lockout/tagout procedures.

If an entire system will need to be shut down and serviced at the same time, a single lockout/tagout procedure should be created that includes all components and energy sources of the system. This is typically used for annual PMs or plant shutdowns.

However, routine maintenance tasks that occur more frequently may only require part of the machine to be shut down, such as a single pump or conveyor. In this case, if the component can be safely isolated from the system and worked on independently, a component-specific procedure should also be developed.

When to Use a Partial Lockout Procedure

Partial lockout procedures can be developed for specific tasks when full lockout is impractical and components cannot be isolated from the system. Additional safety measures must be taken to provide additional protection to the employee performing maintenance.

Benefits of an Alternative De-Energization Procedure (ADP)

There are many reasons an employer may choose to perform a partial lockout or use an ADP:

  • It provides employees specific, standardized steps.
  • It defines the laminations of the partial lockout and lists the specific tasks that can be performed.
  • It allows minor tasks to be performed without shutting down the entire system.
  • It can be more efficient for routine tasks.

Necessary Components of an ADP

  • Identify the machine or component covered by the ADP.
  • List the specific tasks that can be performed.
  • List necessary tools or equipment.
  • List extra PPE required, if applicable.
  • Identify possible hazards.
  • Include specific steps for shutting down the machine, isolating the component, and controlling energy source.
  • Include extra safety steps to be taken.