What is a Permit to Work?

The Role of Permits in Safety Management

Permit to Work systems sit within the administrative controls level of the Hierarchy of Controls. Unlike engineering controls that physically prevent access to hazards, permits rely on human behaviour and procedural compliance. This makes them inherently fragile but essential when hazards cannot be eliminated or engineered out.

The system creates a structured pause before high-risk work begins. It forces a conversation between the asset owner and the work team, ensuring that current site conditions have been assessed, not just generic risks. A permit signed in an office without visiting the worksite offers no protection—the critical value lies in the verification process, not the signature itself.

In Australian industry, permits function as evidence of due diligence. Under the Model Work Health and Safety Act, the Person Conducting a Business or Undertaking (PCBU) must ensure a safe system of work. For non-routine or high-risk activities, a properly implemented PTW system demonstrates that duty has been taken seriously.

When Permits Are Required

Not every task requires a permit. Routine operations governed by Standard Operating Procedures and training don't need additional authorisation—requiring permits for everything would dilute their significance and create compliance fatigue.

Permits are reserved for non-routine work or activities with severe consequences if controls fail. Under Australian WHS regulations and industry standards, specific activities mandate formal permits, most notably confined space entry under Regulation 67 of the Model WHS Regulations. This regulation makes it a criminal offence to allow confined space entry without a valid written permit, regardless of whether an incident occurs.

Other high-risk activities typically requiring permits include hot work (welding, cutting, grinding), work at heights, work on high-voltage electrical systems, excavation near buried services, and any task requiring complex isolation of hazardous energy. The distinction between routine and permit-required work should be clearly defined in each organisation's Safety Management System.

The Permit Lifecycle

A permit follows a structured lifecycle designed to ensure checks occur at the right time and accountability is maintained throughout the work duration.

Initiation and scope definition begins when the work supervisor defines exactly what needs to be done. Precision matters here—vague descriptions like "repair pump" are insufficient. The scope must specify "unbolt flange, remove impeller, replace seal" to prevent unauthorised scope expansion once work begins.

Risk assessment and preparation follows, linking the permit to a Job Safety Analysis or Safe Work Method Statement. The permit issuer reviews this documentation against current site conditions, asking whether the planned method remains valid given today's weather, adjacent work, or recent plant modifications.

Isolation and verification represents the most critical phase. Energy sources must be locked out, atmospheric conditions tested, and hazards controlled. The permit issuer physically prepares the worksite before authorisation can be considered.

The walkdown is where the permit system either succeeds or fails. The issuer and the work supervisor must visit the site together, verify isolations are in place, check emergency equipment is present, and confirm the work area is properly demarcated. Only then does the issuer sign the permit, transferring local control to the work supervisor. Signing permits remotely without site inspection is a common failure mode identified in incident investigations.

Work execution occurs under the permit's conditions. Workers sign onto the permit acknowledging they understand the requirements. Conditions may require continuous monitoring—atmospheric testing every 30 minutes in confined spaces, or a dedicated fire watch for hot work. If site conditions change, work stops and the permit is suspended.

Completion and closeout ensures the work area is returned to a safe state. The work supervisor declares the site clean, the issuer inspects the completed work, isolations are removed in the correct sequence, and the permit is formally cancelled. This closure loop prevents isolations being left in place inadvertently.

Roles and Responsibilities

Clear role definition prevents the accountability gaps that precede incidents.

Specialist Permit Types

Different hazards demand specific permit forms with unique data fields and verification requirements. A generic permit cannot satisfy the detailed controls needed for specialised high-risk work.

Confined Space Entry Permits are mandated by Regulation 67 of the Model WHS Regulations and must include specific elements. Atmospheric monitoring results must be recorded—oxygen between 19.5% and 23.5%, flammable gases below 5% LEL for hot work or 10% for entry, and toxic gases within safe limits. The permit must specify monitoring frequency and record the gas detector's serial number to prove calibration. A confined space permit is invalid without an attached rescue plan specific to that space.

Hot Work Permits follow AS 1674.1, which mandates a 15-metre clearance zone around ignition sources. The issuer must verify all combustible materials within this radius are removed or covered with fire-resistant blankets, checking both sides of walls as heat conducts through barriers. A fire watch must be nominated and must remain on duty for 30 minutes after welding stops to detect smouldering fires. The permit cannot be closed until this post-work monitoring is complete.

Electrical Isolation Permits enforce the "test for dead" procedure required by AS 4836. The issuer must demonstrate to the work supervisor that isolation is effective by attempting to energise the equipment. The permit is then locked in a group isolation board, physically preventing re-energisation until the permit is surrendered.

Excavation Permits require verification that buried services have been located, ground conditions assessed, and appropriate shoring or batter slopes calculated. In Australian urban environments, striking underground utilities remains a persistent hazard controlled through permit systems.

Permits vs Other Safety Documents

Australian workplaces use several overlapping safety documents, creating confusion about their distinct purposes.

A Safe Work Method Statement (SWMS) is legally required for high-risk construction work under the WHS Regulations. It describes how work will be done safely, listing each step and its controls. The SWMS is prepared by the contractor before arriving on site and can be a standing document for a project, though it must be reviewed if conditions change.

A Job Safety Analysis (JSA) is typically a company policy requirement rather than strict regulation, though it satisfies the duty to assess risk. It breaks tasks into steps and identifies hazards for each. The JSA provides the input for the permit—you analyse the job to determine what controls to list on the authorisation.

The Permit to Work is the authorisation itself. Where the SWMS shows you know how to do the work safely, the permit grants permission to do it now under current site conditions. The SWMS might say "we will test for gas before welding," but the permit verifies "we tested for gas at 09:15 today, result was 0% LEL, signed by J. Smith." The permit bridges generic methods and specific site reality.

Learning from Australian Incidents

Major disasters have shaped permit system requirements in Australia, demonstrating the catastrophic consequences when these administrative controls fail.

The 1998 Esso Longford gas plant explosion killed two workers and cut gas supply to Victoria for weeks. The Royal Commission identified fundamental permit system failures, particularly during shift handover. A critical maintenance activity was occurring, but incoming supervisors were not adequately briefed on the plant's destabilised state through the permit handover process. The permit had become paperwork rather than a genuine risk communication tool. This disaster led to major overhauls of permit requirements for Major Hazard Facilities.

The 2020 Grosvenor coal mine explosion critically injured five workers when methane ignited on the longwall face. The Queensland inquiry found that the "Permit to Mine" system had deteriorated through normalisation of deviance—frequent methane exceedances were occurring but production pressure prevented proper investigation. Critically, the inquiry identified that casualised labour hire workers feared raising safety concerns or delaying production to challenge permit conditions. The permit system was technically in place but psychologically undermined, rendering it ineffective.

These cases demonstrate that permit systems fail not just through missing signatures but through cultural erosion. When permits become tick-box exercises completed under production pressure, they provide no protection and serve only as evidence of safety system failure during prosecution.

Digital Transformation of Permits

Australian industry is shifting from paper-based permit books to digital systems, offering significant safety improvements while introducing new risks that must be managed.

Digital systems provide real-time visibility—safety managers can view dashboards showing all active permits across the site, critical information during emergencies for knowing exactly who is in confined spaces or conducting hot work. Modern applications use geofencing to prevent permit signatures unless the mobile device is physically at the work location, eliminating remote signing without site inspection.

Workflow enforcement prevents permits being issued if prerequisites are missing—expired gas detector calibrations, lapsed training competencies, or conflicting simultaneous work. Integration with other systems means isolation certificates, atmospheric test results, and rescue plans are attached automatically rather than manually collated.

However, digital systems create new risks. Copy-paste errors are easier—cloning yesterday's permit can carry forward outdated information like previous day's gas readings or weather conditions. There is risk of screen fixation where users focus on satisfying software fields rather than observing physical hazards. In remote Australian mining and construction locations, cloud-based systems must have robust offline capabilities to ensure permits remain accessible when internet connectivity fails.

Best Practices for Australian Compliance

To ensure permit systems meet legal requirements and function effectively, Australian organisations should implement several key practices.

Competency-based authority means permit issuer designation is based on demonstrated competence, not just seniority. Specific training units like MSMPER200 are often required in resources sectors. Authority to issue permits should be limited to those trained in the specific hazards of each area—only the ammonia plant supervisor issues permits for ammonia areas.

Visual management requires active permits to be displayed at worksites in weatherproof holders, allowing inspectors and other workers to verify current status. A central permit board in the control room should mirror field status using tags, providing a single source of truth for the entire site's current high-risk work.

Stop work authority must be explicitly stated on permits—any person on site can suspend a permit if conditions have changed or appear unsafe. This creates the psychological safety needed to prevent the fear of reprisal that undermined the Grosvenor mine permit system.

Field auditing goes beyond checking paperwork to verify actual understanding. Safety advisors should visit active jobs and ask permit holders to explain their permit conditions without reading the document. If they cannot answer, the communication function of the permit has failed regardless of signatures.

References

• Safe Work Australia, Model Code of Practice: Confined Spaces, Australian Government, 2022
• Safe Work Australia, Model Work Health and Safety Regulations, Regulation 67, 2022
• Queensland Coal Mining Board of Inquiry, Coal Mining Safety and Health (Grosvenor Mine) Report, State of Queensland, 2020
• Standards Australia, AS 1674.1:2022 Safety in welding and allied processes—Fire precautions
• Standards Australia, AS 2865:2023 Confined spaces