High-Risk Work Permits

Energy Isolation Permit (LOTO)

Written by Pirkka Paronen

Reviewed by Tomi Lehtinen

Key Points

Every energy source — electrical, mechanical, hydraulic, pneumatic, thermal, and chemical — must be identified and isolated.
Each worker must apply their own personal lock and tag to every isolation point before starting work.
A zero-energy verification test must confirm that all stored or residual energy has been dissipated.
Locks must only be removed by the person who applied them, unless a documented override procedure is followed.
The isolation register must record all lock and tag applications along with responsible personnel.

Definition

Ensures that all hazardous energy sources are isolated before work begins. This includes electrical, mechanical, and pressure energy. Proper isolation prevents accidental start-up or release of energy.

Related Terms

Hazardous Energy

Hazardous energy includes any form of energy that can cause harm if released unexpectedly. This includes electrical, mechanical, hydraulic, and thermal energy. Proper control is essential before work.

Permit to Work (PTW)

A Permit to Work is a formal control process used to manage hazardous work activities in industrial environments. It ensures that work is properly planned, risks are identified and mitigated, and responsibilities are clearly assigned before work begins. The permit defines conditions under which the work can be carried out, including required safety measures, isolations, and approvals. In practice, PTW acts as the central coordination tool between operations, maintenance, and contractors to prevent accidents and conflicts between activities.

Job Safety Analysis (JSA)

A Job Safety Analysis is a structured process used to break down a task into individual steps and identify hazards associated with each step. For every identified risk, appropriate control measures are defined to reduce or eliminate the hazard. JSA is typically prepared before work begins and is often linked directly to the permit. In practice, it ensures that work is systematically thought through rather than executed based on assumptions.

Permit Lifecycle

The permit lifecycle describes all stages a permit goes through, from creation and submission to approval, execution, suspension, and closure. Each phase includes specific checks and responsibilities to ensure safety. Digital systems often enforce this lifecycle through workflows. In practice, understanding the lifecycle is key to maintaining control and traceability of work.

Audit Trail

An audit trail records all actions taken in a system, providing full traceability. It is essential for compliance and investigations.

More in High-Risk Work Permits

Hot Work Permit

A hot work permit is required for activities that generate heat, sparks, or flames, such as welding or cutting. These activities pose a fire or explosion risk and require strict controls like fire watch and gas testing. The permit ensures all precautions are in place before work begins.

Confined Space Entry Permit

This permit is required for entering enclosed or restricted spaces where hazards such as lack of oxygen or toxic gases may exist. It includes requirements for gas testing, rescue plans, and supervision. These environments are high-risk due to limited escape options.

Lifting Permit

A lifting permit governs operations involving cranes or lifting equipment. It ensures load calculations, equipment checks, and safe lifting plans are in place. Poorly managed lifting can result in serious accidents.

Work at Height Permit

This permit is required when working at elevated heights where fall hazards exist. It ensures proper use of fall protection systems and safe access. Falls are one of the most common causes of injuries in industry.

View all 6 High-Risk Work Permits terms →

Frequently Asked Questions

What happens if a worker leaves site without removing their lock?

A formal lock removal procedure must be followed that includes verifying the worker is not on site, confirming the equipment is safe, and documenting the override with management authorization. Unauthorized lock removal is strictly prohibited.

Can group lockout be used instead of individual locks?

Group lockout is permitted when multiple workers service the same equipment. A designated authorized person applies the primary lock, and each worker adds their own lock to a group lockbox. No lock may be removed until all workers have signed off.

How does LOTO relate to the permit-to-work process?

LOTO is typically a prerequisite step within the PTW process. The isolation must be confirmed and verified before the main work permit is approved. The permit references the isolation certificate and both are closed out together.