What Is a Permit to Work (PTW) System?

The Permit to Work (PTW) process is a key element of Control of Work (CoW). It is used to ensure that work is carried out in a safe and environmentally sound manner. The PTW system requires a work permit to be reviewed and approved before work begins, helping identify the work scope, hazards, controls, responsible personnel, and possible interactions with other activities.

Roles and Responsibilities in the PTW System

Permit Authority

The Permit Authority is normally the Facility, Site, or Project Manager. This role has overall responsibility for the operation of the Permit to Work procedure within the assigned area.

Key responsibilities include:

• Monitoring and auditing the PTW procedure regularly.
• Acting on audit findings and recommending improvements.
• Authorizing Area Authorities, Performing Authorities, and Issuing Authorities.
• Ensuring required training and competency standards are followed.
• Authorizing all categories of Work Permits.
• Approving lessons learned and audit activities.

Area Authority (AA)

The Area Authority is responsible for the day-to-day management of the PTW process within a defined area. This role may normally be performed by a Facility Manager, Deputy Facility Manager, Project Manager, Site Manager, or another suitably assigned individual.

The AA is responsible for:

• Safe control of non-routine work activities.
• Ensuring the appropriate level of risk assessment is completed.
• Working with the Performing Authority to identify hazards and controls.
• Confirming that agreed control measures are implemented.
• Ensuring workers understand the work scope and are briefed through a Toolbox Talk or equivalent communication.
• Supporting the culture of “STOP the Job” when anyone feels unsafe or uncertain.
• Approving isolation design and control-isolation implementation.
• Ensuring effective handovers during shift or crew changes.

Issuing Authority (IA)

The Issuing Authority may be a Lead Technician or Supervisor responsible for normal operations within a particular discipline. The IA must have appropriate additional training and knowledge of safe working practices.

The IA is responsible for:

• Supporting the AA in the safe control of work activities.
• Issuing Work Permits within the assigned area.
• Confirming that the work follows the Permit, JSEA, Safe Work Plan, and applicable risk assessment.
• Working with the PA to identify hazards and appropriate controls.
• Confirming that required control measures are implemented before the Permit becomes active.
• Confirming that workers understand the work scope and have been properly briefed.
• Monitoring the time limits specified on Permits.
• Confirming that personnel working under the PTW system are appropriately trained.

The same person cannot act as both IA and PA for the same task.

Performing Authority (PA)

The PA’s main responsibilities include:

• Initiating the Permit and identifying hazards and control measures.
• Participating in risk assessments where required.
• Conducting Toolbox Talks to ensure workers understand the work scope, hazards, and controls.
• Ensuring only authorized personnel participate in the permitted work.
• Stopping and reassessing work when Permit conditions change.
• Recording and implementing supplementary controls.
• Ensuring work remains within the approved Permit scope.
• Capturing lessons learned from the job.
• Maintaining a clean and safe worksite during and after the work.
• Conducting appropriate handovers during shift and crew changes.

General Requirements of a Permit to Work

A Permit to Work is used to provide structured control over potentially hazardous and non-routine activities. The PTW form must be reviewed and approved before work starts.

A Permit helps to:

• Identify the scope and location of a specific task.
• Communicate work activities across the facility.
• Identify hazards and associated controls through the JSEA process.
• Identify personnel responsible for oversight.
• Identify personnel performing the work.
• Assign responsibilities for different tasks.
• Identify potential SIMOPS issues.
• Identify energy isolations and Lockout/Tagout requirements.
• Verify adequate control when returning equipment or operations to normal conditions.

Types of Permit to Work

The PTW procedure described in the source document uses five main types of permits, each designed to control a particular category of work.

Hot Work Permit

A Hot Work Permit is required for activities involving flames or other sources of ignition.

Examples include:

• Electrical welding and use of welding machines.
• Flame cutting.
• Grinding that produces sparks.

Where applicable, Hot Work may also require a Lockout/Tagout Permit.

Cold Work Permit

A Cold Work Permit is required for potentially hazardous work that is not covered by another specific Permit type.

Examples include:

• Chemical cleaning and use of solvents.
• Handling hazardous substances.
• Use of resins during blade repairs.
• Painting activities.
• Heavy lifting.
• Erection or dismantling of scaffolding.
• Non-routine and potentially hazardous activities.
• Activities requiring specific safety controls.

Electrical Permit

An Electrical Permit is required when work on electrical systems may involve contact with energized electrical conductors.

Examples include:

• Installation or repair of electrical conductors.
• Connection or disconnection of electric motors.
• Work inside panels, transformers, or other electrical enclosures where energized components may be present.
• Work on instrumentation, instrument panels, or telecommunications equipment.
• Removal of circuit components outside normal operating conditions.

Confined Space Entry Permit

A Confined Space Entry Permit is required before personnel enter a confined space, such as a blade, trench, tank, or vessel.

The permit allows access and inspection. If hot work, cold work, electrical work, or energy isolation is also required inside the confined space, the appropriate additional permit must be obtained and cross-referenced.

Ground Disturbance Permit

A Ground Disturbance Permit is required for activities involving digging, trenching, excavation, or removal of soil.

The procedure requires a “One Call” to the appropriate agency before work begins so underground utilities can be identified. Where mechanical excavation equipment is used, a designated spotter may be required to monitor overhead power lines and observe for unusual objects or sounds from the excavation.

Permit to Work Initiation Procedure

A Work Permit must be completed and approved at the beginning of each workday before work commences. The permit is treated as a daily permit and must be signed off at the end of the workday with comments regarding progress.

The PA begins the process by completing the required sections of the Work Permit. Where the work involves Energy Isolation, Hot Work, Confined Space, or Ground Disturbance, the relevant additional permits must also be initiated.

The PA must complete a JSEA identifying:

• Key steps of the task.
• Hazards associated with each step.
• Control measures required for each identified hazard.

The completed Permit and JSEA are then submitted to the IA for review. Following IA approval, the Permit is taken to the AA for review and approval where required.

Permit Approval

The Permit and JSEA application must be reviewed by the Area Authority to determine the potential impact of SIMOPS and other proposed activities.

The review should confirm that:

• Potential hazards have been identified.
• Appropriate precautions have been specified.
• Interactions with other activities have been considered.
• Sufficient information has been provided to safely control the work.

If the information is insufficient, the application should be rejected and resubmitted after the required information has been provided.

Permit Preparations Before Work

Before a Permit is issued, the IA must confirm that the necessary precautions have been defined, implemented, and maintained.

Potential hazards arising from ongoing or conflicting activities must also be identified. Additional precautions should be implemented when necessary.

A Permit should only be issued after:

• Required safety equipment is available.
• Defined isolations have been fully implemented.
• Necessary precautions are in place.
• Relevant hazards and SIMOPS have been considered.

Commencement of Permitted Work

Before work begins, the PA must explain the Permit conditions to everyone involved using the JSEA process. Personnel working on the permitted job must sign the JSEA maintained at the worksite.

If new personnel join an active Permit, the PA must review the work scope, hazards, controls, and Permit conditions with them before they begin work.

Workers also have the responsibility to stop work if they believe conditions are unsafe. The concern should be communicated immediately, the worksite made safe, and the PA and/or IA informed.

If the work scope changes, a new Permit of the appropriate type must be applied for when required.

Work Progress and Permit Continuation

If work is completed during the shift, the Work Completed requirements should be followed.

If work remains incomplete at the end of the shift or is suspended and intended to continue later, a new Permit must be issued in accordance with the procedure.

The PA must ensure that Permit conditions are explained to personnel before they begin work and that newly involved personnel are properly briefed and recorded on the JSEA.

Work Completion, Delay and Permit Invalidation

When work is completed or a Permit becomes invalid, the PA must ensure that:

• The worksite is left safe and tidy.
• All personnel have been withdrawn.
• The IA is informed of the work status.
• Affected plant, process, and equipment are left in a safe condition.

The IA must check the site. If delayed work is later resumed, a new Permit must identify the previous isolation status, precautions, conditions, and any new requirements.

Permit documentation must be retained at the worksite for the specified minimum period. Lessons learned from unique or complex activities should also be shared through the Lessons Learned process.

Emergency Suspension and Cancellation of Permits

During an emergency situation or site alarm, all Permits are suspended. Personnel must disengage from the work and work activities must stop.

Before work resumes, the work area must be assessed by the PA. If the area is considered safe, the PA informs the IA and the IA authorizes work to resume.

A Permit is also immediately suspended when a worker invokes the “STOP the Job” procedure because of a real or perceived safety hazard.

If the work exceeds the approved Permit scope or the scope is inaccurately described, the Permit must be cancelled. The reason must be communicated to the IA and AA, and corrective actions must be completed before a new Permit is submitted.

Limitation of Active Permits

To maintain effective control over work activities, the AA and IA may establish a limit on the number of active Permits that an IA can manage at one time.

Additional Permit applications may be held until existing Permits are cancelled or suspended.

Permit Duration

Permits must be approved for the specific work scope and time period stated on the Permit.

A Permit must be suspended and reissued when:

• One work shift has ended, subject to the specified maximum duration.
• The work plan deviates from the original plan.
• The work scope changes.
• Personnel involved in the work change.
• An emergency alarm is sounded.

Training and Competency Requirements

All personnel involved in the Permit to Work system must receive appropriate training and be assessed as competent for their assigned responsibilities.

The required competency should be confirmed during task planning. The Area Authority and/or relevant supervisor should ensure that new personnel have appropriate and acceptable competency certification before participating in the PTW process.

Auditing of the Permit to Work System

Site management should conduct periodic audits of the PTW system. Audits should include a review of documentation as well as discussions with personnel involved in Permit issue and receipt.

The audit should cover areas such as:

• Personnel competency.
• Permit documentation.
• Handovers.
• Toolbox Talks.
• Permit implementation.
• Control measures.
• Continuous improvement.

The completed audit documentation should be retained according to the applicable procedure, and the PTW procedure itself should also be reviewed periodically.

Importance of an Effective PTW System

An effective Permit to Work system provides a structured method for controlling hazardous and non-routine work. It helps organizations identify hazards, establish controls, define responsibilities, manage interactions between work activities, and ensure that work does not begin until appropriate precautions are implemented.

A strong PTW system also supports a positive safety culture by giving workers the authority to “STOP the Job” whenever they believe conditions are unsafe or uncertain.