Quick answer: A hot work permit is a written authorisation that must be completed before any work involving open flames, sparks, or heat is carried out in an area where there is a risk of fire or explosion. It records the location, task, controls, fire watch arrangements, and the time the permit is valid.
Last reviewed: June 2026 by the BlueSafe Technical Team. Reflects current Model WHS framework.
If your business performs welding, grinding, cutting, brazing, soldering, or any other work that generates sparks, open flame, or significant heat — you almost certainly need a hot work permit before starting. It is one of the most widely used permit-to-work documents on Australian construction sites, in manufacturing facilities, in maintenance environments, and in any workplace where ignition sources and flammable materials can share the same space.
This guide explains what a hot work permit is, what it controls, what it must record, and how it connects to your broader permit-to-work system and your hot work Safe Work Method Statement (SWMS).
What is a hot work permit?
A hot work permit is a site-specific, time-limited written authorisation that approves a named person or crew to carry out hot work at a defined location. It is a type of permit-to-work — a formal document used to control non-routine or high-risk tasks where standard operating procedures alone are not enough to manage the hazard.
Hot work, in the WHS context, means any task that introduces a source of ignition — including but not limited to:
- Welding (MIG, TIG, stick, oxy-acetylene)
- Grinding (angle grinders, disc cutters, bench grinders)
- Cutting (plasma cutting, oxy-fuel cutting)
- Brazing and soldering
- Thermal spraying and heat treatment
- Use of open flames (gas torches, blow lamps, bitumen burners)
- Power tools that generate significant sparks in environments where flammable vapours or dust may be present
The common thread is ignition risk. Hot work permits exist because fires and explosions caused by hot work are a leading cause of serious workplace incidents — including fatalities — and because many of these incidents happen in areas that were not expected to be hazardous, or in circumstances where controls were assumed rather than confirmed.
What does a hot work permit control?
The primary hazard a hot work permit manages is fire and explosion risk. It does this by requiring a physical check of the work area before work begins and by establishing specific control measures that must be in place before the permit can be signed off.
Area clearance
All flammable and combustible materials must be removed from the hot work zone — typically a minimum radius of five metres — or protected with non-combustible coverings. This includes flammable liquids, gases, cardboard, timber, plastic sheeting, and any other materials that could ignite from a spark or radiant heat.
Atmosphere testing
In confined spaces, tanks, vessels, pipe systems, or any area where flammable gases or vapours may be present, the atmosphere must be tested with a calibrated gas detector before hot work commences and periodically during the work. An atmosphere that is within the flammable range must not be worked in until it has been ventilated and retested.
Fire suppression equipment
Appropriate fire extinguishers must be immediately available at the work site and be in date. In higher-risk environments, a charged hose reel or fire blanket may also be required. The permit should record what equipment is in place and confirm it is serviceable.
Fire watch
A fire watch is a designated person whose sole responsibility during hot work — and for a defined period after work stops — is to watch for fire. The fire watch must have direct line of sight to the work and be equipped with a serviceable extinguisher. They must not perform any other duties while acting as fire watch.
Post-work monitoring
Fires frequently start after hot work has finished — sometimes 30 minutes, sometimes hours later, as smouldering material ignites surrounding combustibles. The permit must specify a post-work monitoring period — typically a minimum of 30 to 60 minutes — during which the fire watch remains on site after hot work stops. Some sites require checks at regular intervals for several hours after completion.
Hot work exclusion around flammable substances
Most permit systems include a mandatory standdown rule: hot work must not be conducted within a specified distance of flammable liquid or gas storage, active pipework containing flammable substances, or spray painting operations. Where hot work near these hazards cannot be avoided, additional controls and separate approvals are required.
What does a hot work permit record?
A well-designed hot work permit captures all of the information needed to demonstrate that the work was properly authorised and that controls were in place. The following fields are standard:
- Work location — the specific area, building, floor, or asset reference where the hot work will occur
- Description of work — the type of hot work being carried out and the equipment being used
- Name of worker(s) — the individuals authorised to perform the hot work
- Date and validity period — the date the permit is issued and the start and expiry time
- Pre-work checks — a checklist confirming area clearance, atmosphere testing (if required), extinguisher availability, and fire watch arrangements
- Fire watch name — the designated fire watch person and their contact details
- Post-work monitoring period — how long the fire watch will remain on site after work stops
- Issuer/approver name and signature — the authorised person who has assessed the area and approved the work
- Worker acknowledgement — signature of the worker confirming they have read and understood the permit conditions
- Cancellation or completion sign-off — confirmation that the work has been completed and the area is clear
Completed permits must be retained as part of your WHS records. In the event of an incident or audit, the permit is your evidence that the risk was assessed and controlled.
When is a hot work permit required?
A hot work permit is required whenever hot work is to be carried out:
- Outside a purpose-built, permanently designated hot work area (such as a dedicated welding bay that has been engineered for hot work and is not shared with flammable materials)
- On any construction site — virtually all principal contractor WHS management plans require permits for hot work regardless of where on site it occurs
- In maintenance environments including buildings, facilities, plant rooms, and infrastructure
- In or near any area with flammable or combustible materials, including warehouses, workshops, retail stockrooms, and mechanical spaces
- In or adjacent to confined spaces
- On vessels, tanks, or pipework that has contained flammable substances
- Wherever your site WHS plan, client, or principal contractor requires one
Even in workplaces that have a permanent hot work area, a permit may still be required if work is to be carried out outside that area or if the permanent area is being used in an unusual way.
How the hot work permit fits into your permit-to-work system
A hot work permit is one component of a broader permit-to-work (PTW) system — a formal set of controls that your business uses to authorise high-risk non-routine work. Other common permit types include confined space entry permits, electrical isolation permits, and working at heights permits.
The permit-to-work system provides a consistent framework: before the work starts, someone with appropriate authority must check that the controls are in place and sign off. During the work, the permit conditions must be followed. After the work, the permit must be closed out.
The hot work permit does not replace your hot work SWMS. The two documents work together:
- The hot work SWMS describes how the work will be done safely — the step-by-step method, the required PPE, the hazards and controls that apply to that type of work generally
- The hot work permit confirms that those controls have been applied to the specific location and time the work will occur
Think of the SWMS as the standing method and the permit as the site-specific sign-off that the method has been checked and is ready to execute.
For more detail on how permit-to-work systems are structured and what documents they require, see our guide to permit-to-work systems.
For guidance on what a hot work SWMS must contain and when it is required, see our hot work SWMS guide.
Example: what a hot work permit authorisation looks like in practice
A maintenance contractor is engaged to repair a steel beam in an occupied warehouse. The beam is near racking stacked with cardboard packaging and plastic-wrapped goods. The work will require angle grinding and MIG welding.
Before work starts, the site supervisor:
- Reviews the contractor's hot work SWMS and confirms the method is appropriate for the location
- Walks the hot work zone with the contractor and identifies combustibles within five metres of the work area
- Arranges for the racking in the hot work zone to be cleared or covered with fire-rated blankets
- Confirms that two serviceable dry powder extinguishers are available at the work face
- Designates a fire watch from the warehouse team and confirms their availability throughout the work and for 60 minutes after completion
- Completes and signs the hot work permit, recording all of the above
- The contractor reads and signs the permit before work begins
When the welding is complete, the fire watch monitors the area for 60 minutes, checks for any smouldering, and signs off the completion section of the permit. The permit is filed with the site's WHS records.
Frequently asked questions
Is a hot work permit legally required in Australia?
There is no single clause in the Model WHS Regulations that names a "hot work permit" by title, but PCBUs have a duty to manage fire and ignition risks so far as is reasonably practicable. In practice, a hot work permit is the recognised control for doing this — it is required under most site-specific WHS management plans, construction work plans, and principal contractor rules. In some states and territories, fire safety regulations and codes of practice also require a permit system for ignition sources in certain environments.
Who can issue a hot work permit?
The issuer must be a competent person — typically a supervisor, site manager, or safety officer who has the authority and knowledge to assess fire risk in the area, confirm that controls are in place, and authorise the work to proceed. The issuer and the person doing the work should not be the same individual. Some workplaces also require the permit to be co-signed by a fire warden or emergency coordinator.
How long is a hot work permit valid?
Most hot work permits are issued for a single shift or a defined block of time — commonly no more than eight hours. If work runs over, a new permit should be issued rather than extending the existing one. Some permits are site-specific and expire at the end of the working day regardless of when they were issued. The validity period should always be recorded on the face of the permit.
What is the difference between a hot work permit and a hot work SWMS?
A hot work SWMS describes the step-by-step method for doing the task safely — it covers how the work will be done, what PPE is required, and what controls apply. A hot work permit is a site-specific authorisation document — it records that the controls described in the SWMS and other site requirements have been checked and are in place for a particular location and time. You need both: the SWMS sets the safe method, the permit confirms the method has been applied.
Get your hot work permit template
BlueSafe Online gives you access to ready-to-use WHS document templates including hot work permits, permit-to-work registers, and supporting SWMS templates — designed for Australian workplaces and built to satisfy audit and principal contractor requirements.
This guide provides general information only. Requirements will depend on your industry, the nature of the work, applicable state and territory legislation, and any contractual obligations.