Updated July 2025
Hot work — such as welding, cutting, grinding, or using open flames — can pose serious fire and explosion risks when carried out in the wrong environment. To prevent accidents and comply with legal obligations, employers are required to implement strict safety controls. One of the most effective methods of managing this risk is through a hot work permit system.
A hot work permit is a formal safety document that authorises high-risk activities involving heat, sparks, or flames. It ensures that adequate precautions are in place before work begins, especially in areas not specifically designed for hot work. In this guide, we’ll explain what a hot work permit is, when it’s needed, and how to manage hazards associated with hot works on site.
Related Reading — Guide To Workplace Health And Safety Training In Construction
What Is Hot Work?
Hot work refers to any activity involving open flames or other heat sources, sparks, or flame-producing equipment.
Common types of hot work include:
- Welding: joining materials by melting them together with high heat.
- Cutting: using torches or saws to cut through metal or other hard materials.
- Grinding: using abrasive wheels or cutting disks that create sparks.
- Brazing: joining metals by melting and flowing a filler metal into the joint.
- Soldering: connecting components with a low-melting-point metal alloy.
- Torching: using gas-fuelled torches to apply direct heat.
Hot work is often performed in construction, maintenance, and repair work and can be extremely hazardous if not performed properly.
If proper precautions are not taken, hot work poses a significant risk of fire, explosion, and personal injury. If equipment is misused, workers can be harmed through burns, exposure to fumes, or even electric shocks. For this reason, it is important to have a hot work permit, which outlines the specific health and safety measures that need to be taken to prevent fires and other accidents.
Hot work permits typically involve procedures such as:
- Isolating the work area.
- Identifying and controlling fire hazards.
- Ensuring the presence of appropriate firefighting equipment.
- Confirming all workers are trained in safe hot work practices.
Identifying Hot Work Hazards
Working with high levels of heat and open flames is dangerous, but you need to identify the exact hazards created by hot work activities to conduct a thorough risk assessment and implement effective control measures.
Risk Assessment Considerations
Here are some examples of hot work risks to include in your hazard identification process:
- Electrical Hazards — Most hot work involves using electrical equipment, so workers will face electrical hazards such as the risk of short-circuiting equipment, faulty wiring, shocks, or even fatal electrocution.
- Exposure to Harmful UV or Infrared Light — Hot work activities such as welding can involve potentially dangerous UV or infrared light. If workers are exposed to these types of non-ionising radiation, it can cause damage to their skin or eyes.
- Exposure to Dangerous Fumes — Hot work can produce dangerous fumes that pose major health and safety risks for workers. Fumes can cause respiratory health conditions, burns, flu-like symptoms and eye damage.
- Flying Sparks Can Cause Fires or Combustion — When hot work activities like welding are carried out, sparks can fly and cause fires or combustion if they come into contact with flammable materials, debris or hazardous materials.
- Conducting Heat through Pipes — Heat can be conducted through metal materials like pipes, and, when heat is transferred, it can come into contact with flammable, combustible or otherwise hazardous materials.
- Skin Injuries through Contact with Hot Materials or Equipment — If workers touch equipment, debris or surfaces that are extremely hot — or come into contact with open flames or sparks — they may sustain skin injuries like heat burns, friction burns or cuts.
The above are some hot work hazards that might apply to your workplace. The particular hazards your workers face will depend on the people involved, the area where hot work activities are being carried out, and any hazards specific to your equipment and workplace. Before implementing control measures, you’ll need to make sure you’ve considered all possible risks.
Related Reading: Risk Assessment: A Template And Guide
Hot Work Controls To Keep Workers Safe
Once you’ve identified the hot work hazards in your workplace, you’ll need to plan and implement controls to make your workplace safer and protect workers from harm and ill health.
Like hazards, your control measures should be unique to your business operations and work environment. We’ve compiled some of the hot work control measures you should consider:
1. Avoid Hot Work Where Possible
Hot work is, by its very nature, dangerous. You won’t ever be able to eliminate the risks of working with excessive heat. So, where possible, avoid hot work completely. Consider alternative processes and activities that could have a similar result. For example, rather than welding, can you join items together using mechanical methods such as nuts and bolts or screwed fittings?
2. Clear The Area Where Hot Work Will Be Carried Out
A cluttered workspace with unnecessary materials, equipment, waste or debris has a more significant “fire potential” than a clean, tidy area.
Keeping the area clear where hot work will be carried out keeps fire safety risks to a minimum. This control measure can also reduce other health and safety risks, such as slips and trips, which could have disastrous consequences when coupled with hot work hazards.
A clear area also enables workers to safely evacuate the building in the event of a fire.
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3. Carry Out Hot Work in a Designated Or Prepared Area
Having a designated hot work area can help minimise risks and eliminate or control hazards, but sectioning off a whole work area isn’t always possible for many businesses.
When choosing an area for activities involving heat and flames, avoid places where hazardous substances are stored, as these can further add to the fire potential of a workspace. If it’s impossible to carry out hot work away from hazardous substances, comply with COSHH regulations and ensure substances are stored safely and securely.
Related Reading — What Is COSHH? Hazardous Substance Control Explained
4. Ensure Those Carrying Out Hot Work Are Trained To Do So
The dangerous nature of hot work means it should only be carried out by those with skills, knowledge, experience and training to complete tasks to a high standard while implementing control measures and monitoring health and safety standards.
If there are no workers within your organisation with the necessary or desired level of competence, you may want to consider offering training to an individual or a group of employees. Alternatively, you could bring in an external contractor who can complete hot work while effectively managing risks.
5. Monitor Gas Or Vapour In The Area Being Used For Hot Work
Air that’s contaminated with gas or vapour can cause health and fire risks. Some gases are toxic, while others are flammable or combustible. Workers should be able to monitor gas and vapour in the air to ensure they work in safe conditions. However, because gas can’t be seen, specific monitors must be used.
6. Improve The Overall Fire Safety Of Your Workplace
Many hot work hazards are directly related to the overall fire safety of your workplace. For example, if your business premises have a high fire potential, the risk factor for hot work hazards is increased.
One of the best ways to reduce hot work risks is to improve the overall fire safety of your workplace. Fire safety policies and procedures should be up-to-date, relevant and thorough. Workers should be trained to use fire safety equipment such as fire extinguishers and fire-retardant blankets. They should also be made aware of and trained to follow control measures such as smoke alarms, sprinklers and evacuation procedures.
7. Provide Flame Resistant Garments And Protective Gear
As an employer, you’ll need to provide suitable personal protective equipment (PPE) for workers participating in hot work. This could include extraction equipment, fire-resistant garments, face masks, eye protection and other equipment designed to protect people from heat, sparks, or hazardous fumes and radiation.
Why You Should Also Prepare A Hot Work Permit
Employers in Great Britain are legally required to undertake all operations while demonstrating a safe work system. Therefore, before you start any hot work activities, you should prepare a permit to work system specifically for hot work. The permit should detail the following:
- The work to be carried out
- How and when it will be completed
- Which precautions will be taken to ensure that activities are as safe as possible?
What Is A Hot Work Permit?
A hot work permit is a formal written system that authorises and controls hot work activities. It is a critical component of ensuring the health and safety of workers and preventing fires and explosions during hot work operations.
- The hot work permit typically includes information such as the location and nature of the work, the equipment and tools to be used, the safety measures to be implemented, the persons authorised to carry out the work, and the permit duration.
- The permit also sets out any additional safety measures or precautions that must be taken, such as isolating the work area, removing combustible materials, and ensuring the availability of firefighting equipment.
Done correctly, a hot work permit ensures that all necessary safety measures are in place before work begins and that the work is carried out following established safety standards and best practices.
Overall, a hot work permit system is a critical part of a safe hot work operation and helps to ensure the safety of workers and the surrounding environment.
When Is A Hot Work Permit Required?
A hot work permit is required whenever work involving open flames, sparks, or high heat is carried out in an environment not specifically designed or controlled for such activities. The purpose of the permit is to ensure that all potential fire and explosion risks are identified and mitigated before the work begins.
Hot work permits are not optional — they are a legal and safety requirement under UK health and safety regulations, including the Regulatory Reform (Fire Safety) Order 2005 and the Health and Safety at Work etc. Act 1974. If your risk assessment identifies a significant fire risk, a permit must be issued.
Common Scenarios That Require A Hot Work Permit:
- Welding or cutting metals in or near combustible materials
- Using a blowtorch or heat gun in a confined or unventilated space
- Carrying out hot work in non-dedicated areas (e.g. near timber structures, dry vegetation, or painted surfaces)
- Undertaking roof repairs involving torches or bitumen boilers
- Performing hot work near fuel tanks, gas cylinders, or solvent storage
- Working in hazardous atmospheres, such as those with flammable vapours or dusts
Locations That Typically Require A Permit:
- Construction sites
- Commercial buildings undergoing maintenance or renovation
- Warehouses and manufacturing plants
- Schools, hospitals and care homes
- Petrochemical and industrial facilities
- Confined spaces such as tanks, ducts, or sewers
In general, if the area is not a designated hot work zone —with permanent fire-resistant surfaces, proper ventilation and no flammable materials — a hot work permit must be issued before any activity begins.
Who Issues The Permit?
The Responsible Person (often a site supervisor, facilities manager, or health and safety officer) is accountable for issuing the hot work permit. They must verify that appropriate risk controls are in place and confirm the worker’s competence before authorising the job. The permit should also have a strict validity period, after which it must be reassessed and reissued if the work continues.
Steps For Preparing A Hot Work Permit
Although the exact process of preparing a hot work permit will depend on your organisation — and the type of hot work you do — it should be prepared by someone with the relevant skills, knowledge, experience and training. Ideally, the responsible person isn’t involved in the hot work due to be carried out. However, you should consider input from all workers participating in hot work activities.
- Identify the Hot Work Activity — Determine the type of hot work activity, the equipment and materials that will be used, and the location where the work will be done.
- Conduct a Hazard Assessment — Evaluate where the work will be done, the materials and equipment used, and the potential for fire or explosion. Based on the hazard assessment, identify the necessary controls and precautions to mitigate the risks associated with the hot work activity.
- Develop a Work Plan — Develop a detailed plan that outlines the steps needed to carry out the hot work activity safely. The work plan should include a description of the hot work activity, the work location, the equipment and materials that will be used, the necessary safety precautions, and the emergency procedures to follow.
- Prepare the Hot Work Permit — Prepare a written document that authorises the hot work activity and outlines the safety precautions and controls that must be in place before work can begin. The permit should include details such as the type of hot work activity, the work’s location, the permit’s duration, the person authorised to carry out the work, and the necessary safety precautions.
- Implement the Hot Work Permit — Review the permit to ensure all necessary safety precautions and controls are in place before work begins. Display the permit prominently at the work site, and keep a copy on file for future reference.
- Monitor the Hot Work Activity — Monitor the work to ensure that all safety precautions and controls are being followed. Observe the work to ensure that workers are using the correct equipment and materials and following the established procedures. Ensure that the work area remains free of combustible materials and that all necessary firefighting equipment is readily available.
- Close Out the Hot Work Permit — Inspect the work area to ensure all equipment and materials have been removed and that it is safe for other workers. Sign the permit, indicating that the work has been completed safely and that all necessary controls were in place.
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