9th September, 2023

14 Essential Hot Work Safety Tips

Hot work is a fire hazard and brings additional risks for both your workers and your site. If you need to do some hot work, like cutting, grinding or welding, stay safe with these hot work safety tips.

14 Essential Hot Work Safety Tips header image

Hot work is often a temporary activity, and you might not always carry it out in the same place. And if you are on a construction site, hot work can take place where the building isn't even finished yet.

Safety is essential when you are considering hot work because fires can quickly get out of control and are often catastrophic for the people and buildings involved.

If you're planning hot work on your site, here are our top safety tips.

1. Avoid hot work

You know hot work is dangerous, and the best way to avoid the danger? Don't do it! Seriously, there's a reason why elimination is at the top of the hierarchy of risk control.

If you can avoid hot work, then do. Alternatives like cold cutting or pre-fabricating elements in a more controlled environment might increase costs slightly or require some specialist equipment but once you factor in the management burden, fire watches, and increased fire risk, an alternative method might be less hassle, safer and more productive.

The rest of our safety tips assume you have considered the alternatives, but can't avoid hot work. Onward!

2. Visit the hot work area

Hot work areas need to be safe.

You can't possibly assess the risks without taking a look at the hazards.

Every work area is different, and even if you are familiar with the site and the specific area where the hot work is happening, unless you check it just before the hot work happens, you can't be sure if something has changed.

Maybe a load of packaging has been left there. Maybe some flammable liquids have been used. Maybe the exit route is blocked. Or perhaps it's just had some new equipment installed.

Visit the hot work area and check what's there.

3. Do a risk assessment

Hot work is a source of ignition. And that's a fire hazard.

sparks using angle grinder

Your hot work risk assessment is a record of your visit to the hot work area.

As part of the 5 steps to risk assessment you will:

  1. Identify the hazards
  2. Assess who might be harmed (and how)
  3. Decide on the controls needed
  4. Record your findings
  5. Review and update as necessary

4. Check for flammable substances

If you need to carry out hot work on pipes or tanks, consider if they may contain or have contained flammable substances or gas.

Check what current and previous uses are and check that they have been properly isolated and decontaminated before starting work.

If DSEAR applies, plant and equipment that contained a dangerous substance will need to be:

Clean surfaces and containers of hazardous residues and build-ups and monitor to ensure that flammable gases or vapours do not reoccur during the hot work.

5. Remove combustible materials

A fire needs three things:

  1. Sources of ignition/heat
  2. Sources of fuel
  3. Sources of oxygen

If hot work is the ignition source, then what is the fuel? Combustible materials.


Remove, or cover, combustible materials:

You might not be able to remove all combustible materials, so protect any still present with non-combustible covers or boards.

6. Add fire safety precautions

You've already removed any non-essential flammable substances and combustible materials, but of course, hot work will always carry a risk, so fire safety precautions are essential.

This can include:

If you routinely need to carry out hot work, you can create a safe hot works area for the work. In this controlled zone you can add extra fire safety measures like fire-resisting enclosures, thermal imaging detection and alarms, and sprinkler systems. You can also display hot works procedures and warnings, and exclude any non-authorised people.

7. Check your equipment

Hot work equipment, whether electric or fuel powered, generates heat and/or flames.

Equipment faults could increase the risk to both the worker and the work area by:

Maintain your equipment by following manufacturer instructions, and visually check it is working correctly and free of defects before, during and after use.

electrical fault

8. Store flammable substances safely

Ideally, you won't have flammable substances in the hot work area. But what if you need flammable substances to do the hot work? Like LPG?

Only have the minimum quantities you need in the hot work area, and keep cylinders at least 3m away from any combustible materials or sources of ignition.

9. Use a hot work permit

The best way to control hot work is by using a hot work permit. The permit tells you:

The hot work permit can be used to create general site rules such as only allowing one hot work task to be carried out at any time, or only allowing hot works to be carried out at certain times of the day.

If you have lots of contractors working on a project, e.g. a construction site, hot work permits should be controlled by the principal contractor or the project manager to ensure there is an overall level of control of the hot works happening on the site.


10. Wear PPE

Hot work isn't just a fire risk - heat and sparks can also cause burns and eye damage to workers in the hot work area.

PPE is your last line of defence when you are doing hot work, so while the other safety tips will reduce the risk of a fire in your workplace, you can still get exposed to heat, sparks and fumes from the process.

The PPE worn should be suitable for hot work and the working environment, and can include:

11. Check the fire alarm

Since fire alarms can detect smoke and heat, you might need to disable an alarm to avoid setting it off during hot works. But that creates even more of a risk if you can't detect fires early.

Where possible, only isolate the detector that will be affected by the hot work.

Always ensure you re-activate the fire alarm on completion of the hot work.

fire alarm

12. Reduce the risk to people

Restrict the access within the hot work area to only essential workers. Other people should not be allowed within the work area because:

If a fire does happen, or even start, people need to be evacuated quickly. Because fires can get out of control within seconds.

Consider when you need to do hot work, and if you can do it during times when fewer people are around so that you can reduce the number of people who will be affected.

13. Get two fire extinguishers

At least two fire extinguishers should be available in the hot work area. If one fails, you have a backup. If one runs out, you have another. If two workers are available, they can both tackle a small fire before it gets out of control.

Because of the increased fire risks with hot works, the workers involved should be competent in the use of fire fighting equipment in case they need to use it.

fire extinguishers

14. Fire watch

You should continuously watch for fire during hot work, but the risk isn't over when the hot work ends. Sparks and smoulder can develop into a fire minutes or even an hour later in the right conditions.

Your fire watch should include continued checks an hour after the work, and regular checks at 20-minute intervals for up to 120 minutes after completion.

A fire watch can (and should) be done physically, but if you are regularly doing hot work, investing in thermal imaging equipment can be worthwhile. Rather than waiting until the next physical check, thermal imaging gives you constant monitoring for quicker fire detection.

There should be a continuous fire watch of the hot work area for at least an hour after the end of hot work, followed by at least one more check two hours after the end of hot work.

Don't close the hot work permit until the fire watch is complete, including the last visual inspection of the work area (final fire check).

Download the hot work toolbox talk and take a safety moment with your team to discuss the risks and controls needed for hot work.

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This article was written by Emma at HASpod. Emma has over 10 years experience in health and safety and BSc (Hons) Construction Management. She is NEBOSH qualified and Tech IOSH.

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