Hot work, which includes tasks such as welding, cutting, grinding, and other activities that produce heat, sparks, or flames, is a common requirement in many industries. However, these activities also pose significant risks, particularly the risk of fire or explosion. To mitigate these risks, the implementation of a Hot Work Permit system is essential to ensure that all necessary precautions are taken before, during, and after hot work is performed.
In most organisations, hot work permits sit inside a broader Permit to Work (PTW) framework that covers other high-risk categories like working at height or confined space entry. The difference is that hot work brings a uniquely time-delayed risk: you can finish the job “safely” and still start a fire later from a smouldering source. A good hot work permit process is designed to manage **before, during, and after** conditions.
Understanding the Hot Work Permit
A Hot Work Permit is a formal record that controls hot work activities. It outlines the specific work to be done, identifies potential hazards, and specifies the necessary safety precautions to prevent accidents. The permit also requires authorisation from designated personnel, ensuring that all safety measures are reviewed and approved before work begins.
A practical way to think about the permit is: it should answer 'what, where, who, when, what could go wrong, what are we doing about it, and who has checked?'
The Hot Work Permit document typically includes the following sections:
Description of Work:
This is the operational 'contract' for the task: the exact activity, location, personnel, and schedule.
Examples of strong entries:
Task: 'Cut 6 mm plate with oxy-fuel torch to remove corroded bracket.'
Location: 'Turbine Hall mezzanine, Bay 3, north side, adjacent to cable tray CT-3.'
People: 'ABC Welding Ltd – J. Khan (welder), S. Patel (fire watch).'
Window: '13 Feb 2026, 10:00–12:00; permit valid until 13:00 including fire watch.'
Why the detail matters: 'Workshop' is not a location. 'Bay 3 north side' tells other teams where heat, sparks, and restricted access will exist.
Hazard Identification:
Hot work hazards are rarely just 'sparks'. The permit needs an explicit scan for common hazards such as flammables, combustible dust, and confined/poorly ventilated areas.
Examples of hazards you’d want called out:
- Hidden combustibles: insulation behind cladding, timber packing, oily rags in a void, bitumen roofing layers.
- Combustible dust: flour, wood, plastic, sugar, grain dust (especially where dust can be disturbed).
- Flammable atmosphere risk: solvent use nearby, fuel gas lines, tank vents, battery rooms, paint stores.
- Confined/awkward geometry: ductwork, pits, tanks, or areas with limited escape routes.
- Secondary ignition routes: sparks dropping through grating to a lower level, sparks entering cable trays, or through penetrations in walls/floors.
A good permit also forces you to check what else is happening nearby (SIMOPs): e.g., 'Another team is cleaning with solvent 15 m away' is a huge red flag for hot work timing.
Safety Precautions:
Based on the hazards, the permit should list the specific controls required: removal/segregation of combustibles, barriers, shielding, ventilation, gas testing where relevant, and fire protection readiness.
Practical examples:
- Remove/clean: 'Clear combustibles within 15 m radius; remove waste, packaging, and oily cloths; vacuum dust.'
- Shield/isolate: 'Install fire-resistant blankets around cable tray; fit spark containment curtains.'
- Protect openings: 'Cover floor grating beneath work area; seal wall penetrations to prevent spark travel.'
- Control heat transfer: 'Pre-wet timber surfaces; use heat sink plates behind thin wall sections.'
- Fire readiness: 'Two suitable extinguishers staged within 5 m (CO₂ + foam/water as appropriate), checked in date and charged.'
- Gas testing / monitoring (where appropriate): 'LEL reading < 1%; continuous monitoring required during work in enclosed space.'
The key is avoiding vague controls like 'take care' or 'ensure safe.' Controls should be observable and checkable.
Personal Protective Equipment (PPE):
The permit should specify PPE aligned to the method (welding, cutting, grinding) and the environment.
Examples:
- FR clothing appropriate to arc/heat exposure
- Welding helmet with correct shade; safety glasses underneath
- Heat-resistant gloves; leather apron/sleeves for cutting
- Hearing protection for grinding/cutting
- Respiratory protection if fumes/dust cannot be adequately controlled by local extraction
- Face shield for grinding operations
Authorization and Approval:
The Hot Work Permit must be reviewed and approved by a designated safety officer or supervisor. This authorisation process ensures that a second set of eyes evaluates the work plan and safety precautions, reducing the risk of oversight. The permit is only valid for a specified period, after which it must be re-evaluated and re-authorised if the work is not completed.
Example approval logic:
'Permit valid for 2 hours. Any break >30 minutes or change of location requires re-check and re-issue.'
'If wind direction changes (outdoor work near intakes), stop and reassess.'
Fire Watch Requirements:
In many cases, a fire watch is necessary to monitor the work area during and after the completion of hot work. The fire watch is responsible for identifying and extinguishing any sparks or smouldering materials that could ignite a fire. The permit outlines the duration of the fire watch and any specific instructions they must follow.
Examples:
- 'Dedicated fire watch, no other duties during hot work.'
- 'Fire watch continues for **60 minutes after completion**; extend to 120 minutes where insulation/voids exist.'
- 'Fire watch equipped with extinguisher, radio, and knows alarm/evac procedure.'
- 'Check below/adjacent compartments every 15 minutes during watch.'
(Exact durations vary by industry/site rules—but the principle is explicit, enforced post-work monitoring.)
Post-Work Inspection:
After the hot work is completed, a thorough inspection of the area is required to ensure that no fire hazards remain. The permit includes a checklist for the post-work inspection, which may involve checking for hot spots, ensuring that all equipment is turned off, and confirming that the work area is safe before it is left unattended.
Examples:
- 'Verify equipment powered down; gas cylinders isolated and removed.'
- 'Inspect surrounding area including below grating and behind barriers.'
- 'Check for heat in adjacent metalwork; use thermal checks where available.'
- 'Confirm housekeeping restored; combustibles returned only when safe.'
The Importance of a Hot Work Permit System
Implementing a Hot Work Permit system is not just about compliance; it is a critical component of an organisation’s safety culture.
Preventing Fires and Explosions:
By systematically assessing hazards, implementing safety precautions, and requiring authorisation, the permit system reduces the likelihood of an incident occurring.
Ensuring Accountability:
The permit system ensures that there is clear accountability for hot work activities. The individual who completes the permit is responsible for assessing hazards and implementing precautions, while the authorising officer ensures that the permit meets all safety requirements. This clear delineation of responsibilities helps prevent accidents caused by oversight or miscommunication.
Promoting a Safety Culture:
A Hot Work Permit system reinforces the importance of safety in the workplace. It sends a strong message that safety is a priority and that all workers have a role to play in maintaining a safe work environment. Over time, this can help foster a culture where safety is integrated into every aspect of work.
Facilitating Communication and Coordination:
The permit system improves communication and coordination among different teams and departments. By documenting and sharing details about hot work activities, the system ensures that everyone on site is aware of potential hazards and can take appropriate actions to avoid conflicts or accidents.
Providing Documentation and supporting Compliance:
In the event of an incident or inspection, the Hot Work Permit provides critical documentation that shows the steps taken to ensure safety. This documentation is essential for demonstrating compliance with safety regulations and can protect the organisation from liability.
The Role of Digital Permit to Work Systems
While traditional paper-based Hot Work Permits are effective, many organisations are now adopting digital permit systems to further enhance safety and efficiency.
Real-Time Access and Updates:
A digital permit system allows for real-time access to permits and updates, ensuring that all stakeholders have the latest information. This is particularly useful in large or complex sites where multiple hot work activities may be taking place simultaneously.
Centralised Management:
Digital systems provide a centralised platform for managing all permits, making it easier to track ongoing work, monitor compliance, and generate reports. This centralisation also simplifies the authorisation process, as permits can be reviewed and approved electronically.
Integration with Other Safety Systems:
Many digital permit systems can be integrated with other safety management tools, such as risk assessments, incident reporting, and training records. This integration enhances overall safety management by providing a comprehensive view of all safety-related activities and data.
Improved Record-Keeping:
Digital systems improve record-keeping by automatically storing and organising permits, making it easy to retrieve them when needed. This is particularly beneficial for audits, incident investigations, and compliance reporting.
We've added a short summary of the key points in a downloadable PDF
Learn about the Pisys Permit to Work system below:
