Hot Work Permits: Rules for Welding and Grinding

Which jobs require a hot work permit?

Hot work is work that creates sparks, flames or hot surfaces, such as electric and gas welding, oxy-fuel or plasma cutting, grinding, soldering, hot air guns and heating with an open flame. If this work is carried out routinely in a dedicated welding workshop designed against fire, it is managed through the workshop rules. If it is to be carried out outside the workshop, that is, on top of a machine during maintenance, in a warehouse, on a roof, or on a tank or pipeline, a hot work permit is required.

There is no separate regulation in Turkish legislation called a "hot work permit"; the obligation arises from a combination of several provisions:

Art. 4 and 10 of Law No. 6331 on Occupational Health and Safety give the employer the obligation to assess risks and take the necessary measures.
Annex 2 of the Regulation on the Protection of Workers from the Hazards of Explosive Atmospheres requires a permit-to-work system to be applied for hazardous work where the explosion protection document deems it necessary, and the permit to be issued in writing by an authorised and responsible person before work starts.
Art. 88 of the Regulation on Fire Protection of Buildings prohibits welding without precautions in places where flammable organic dusts such as flour, grain, bran, starch and sugar are present; Art. 109 requires flashback arrestor safety valves on the connections of oxygen and LPG cylinders during cutting, welding and annealing.

We explain how the permit system works in general in our article what is a permit-to-work system. This article goes through the hot work permit form section by section.

The hot work permit form: section by section

The form is a control tool less for the person doing the work than for the people preparing and supervising the area. A hot work permit form should contain the following sections:

Section	Content
Description and location of the work	Welding, cutting or grinding; building, floor, machine or line details
Validity period	Start and end time; usually a single shift. The permit is renewed when the shift changes
Hazard identification	Combustible materials, dust accumulation, oily surfaces, pipe and duct connections, behind walls, residues inside tanks
Area preparation	Clearing an 11-metre radius, covers, closing openings, gas testing if necessary
Equipment check	Hoses, regulators, flashback arrestors, welding cable and electrode holder, grinding disc and guard
Fire-fighting and fire watch	Type and location of the extinguisher, name of the fire watch
PPE	Welding helmet or face shield, gloves, apron, respiratory protection if necessary
Signatures	Permit issuer, area supervisor, person doing the work, fire watch
Closure	Time the work finished, time monitoring finished, signature of the person making the final check

The most neglected section of the form is closure. The permit is closed not when the work is finished, but when post-work monitoring has been completed and the area has been checked for the last time.

Who issues and signs the permit?

The Explosive Atmospheres Regulation requires the permit to be issued by a person who is authorised and responsible in this area. Write who is authorised by name in your procedure; a "whoever is on shift" approach makes the permit meaningless. A typical division of roles is as follows:

Permit issuer: A person with the authority to stop the area and postpone the work, such as the maintenance or production manager. They do not sign without seeing the area in person.
Area supervisor: The supervisor of the department where the work will be carried out. Responsible for the process in the department, combustible materials and the situation of other workers.
Person doing the work: The welder or maintenance technician. Stops the work if the conditions on the form change, for example if the wind starts to carry sparks in another direction.
Fire watch: Present in the area throughout the work and during the monitoring afterwards.

The OHS specialist prepares the form and procedure and checks on site, by sampling, whether permits are being applied correctly; however, they should not be the person who signs every permit alone. The permit is the responsibility of the person who manages the area.

Area preparation and the 11-metre rule

The 11-metre rule for hot work comes from two US sources. OSHA's welding and cutting rules (29 CFR 1910.252) require a fire watch when significant combustible material is within 35 feet (about 10.7 m) of the work point; the NFPA 51B standard is based on the same distance. Sparks and spatter from welding can travel up to this distance. In practice:

Remove combustible material (cardboard, wooden pallets, plastics, textiles, oil drums) within about 11 metres of the work point.
Cover combustibles that cannot be moved with non-combustible blankets or covers; make sure sparks cannot get under the cover.
Sweep the floor; clean up dust, swarf and oil deposits.
Close openings in walls and floors, duct openings and pipe penetrations. Sparks can fall to the floor below or into a neighbouring compartment.
If a wall, partition or tank shell is heated, also check for combustibles on the other side; heat passes through by conduction.
If work is to be done on a tank, pipe or confined space, the contents are emptied and cleaned and a flammable gas test is carried out. The acceptance value is defined in the risk assessment.
Place the extinguisher next to the work point and check that its type is suitable for the combustible material.

In metalworking and machinery manufacturing plants in Bursa and the surrounding provinces, grinding is a hot work task frequently carried out during maintenance; it should not be left outside the permit as a "simple job". Grinding sparks can also travel many metres, so the same rules apply.

Equipment and gas cylinder check

The permit covers not only the area but also the equipment used for the work. Flashback arrestor safety valves on cutting and welding sets are an explicit requirement of the Regulation on Fire Protection of Buildings. Complete the equipment section of the form with these questions:

Are oxygen and fuel gas cylinders upright, secured and away from heat sources? Are the valves of cylinders not in use closed?
Are there cracks, burns or joints in the hoses; are the connections clamped?
Are the regulators and gauges sound, and are flashback arrestors fitted?
Is the welding cable insulation intact, and is the earth return connected close to the work point and to a sound surface? A distant and loose earth can cause current to flow through unexpected paths and lead to heating.
Is the guard fitted on the grinder, and is the disc suitable for the machine's speed and undamaged?

Preparing the area without checking the equipment leaves the permit half done.

Welding fire watch: duties and authority

The welding fire watch is the person whose only job during and after the hot work is to watch for fire. The fire watch must:

Know how to use the extinguisher and fire hose reel,
Know how to raise the alarm and the emergency numbers,
Not be occupied with any other task during the work,
Be able to see the floor below or compartments where sparks may fall, with a second fire watch posted if necessary,
Have the authority to stop the work in an unsafe situation.

Fire watch is not an extra task to be given to the welder doing the work; it is not possible to watch the surroundings from behind a welding helmet. Our fire training service and our article on types of fire extinguisher provide guidance on the fire watch's practical fire-fighting skills.

Fire check after welding: how long should you wait?

After hot work, the greatest risk is smouldering that goes unnoticed and flares up minutes or even hours later. Turkish legislation does not specify a period for this monitoring. In international practice, OSHA rules require fire monitoring for at least half an hour after the work is finished, and the current edition of NFPA 51B requires at least 1 hour.

Common mistakes

Keeping the permit open for days instead of a single shift,
Signing the form without the area being prepared,
The fire watch leaving as soon as the work is finished,
Leaving the extinguisher in a cabinet "nearby",
Keeping a subcontractor's welder outside the permit; for hot work carried out in the principal employer's area, the permit should be issued through the system of the principal employer that manages the area,
Treating grinding as outside the scope of the permit.

For the health and safety risks of welders, see our article on OHS risks for welders, and for sector-specific risks, see our metal and machinery page. You can enter the annual inspection dates of extinguishers in the OHS calendar. For setting up your permit system and monitoring it on site, see our OHS specialist service.

Frequently Asked Questions

Is a hot work permit legally mandatory?

There is no separate regulation called a "hot work permit". However, Law No. 6331 makes it mandatory to assess risks and take measures; and in places with an explosive atmosphere risk, the regulation explicitly requires a written permit-to-work system for hazardous work. A written permit is the most concrete record showing that you have fulfilled this obligation.

Where does the 11-metre rule for hot work come from?

It comes from the 35-foot (about 10.7 m) distance in OSHA's welding and cutting rules and the NFPA 51B standard. If there are significant combustibles within this distance, they are removed or covered and a fire watch is appointed.

How long should the fire watch stay after welding is finished?

Our legislation does not specify a period. OSHA requires at least half an hour of monitoring, and the current edition of NFPA 51B at least one hour. We recommend at least 60 minutes of monitoring and additional check rounds afterwards in areas with a high fire load.

Is a permit also needed for grinding?

Yes. Grinding is also hot work that produces sparks, and the sparks can travel a long way. Grinding carried out outside a dedicated, suitably equipped workshop should also be covered by the permit.