Is a hot work permit a legal requirement?

The law requires that fire risk from hot work is assessed and controlled. A permit is the standard way to do that and most insurers and principal contractors require one. If you do hot work without a permit system you will struggle to show the risk was controlled.

How long should the fire watch last after hot work?

At least an hour after the work has stopped, longer where materials could smoulder. Insurers commonly require 60 minutes with a final check later. Put the time on the permit.

Does welding fume need a COSHH assessment?

Yes. All welding fume is classed as a carcinogen and HSE expects local exhaust ventilation indoors and respiratory protection where extraction cannot control the fume. Do a COSHH assessment for the fume and any coatings on the metal.

Hot works risk assessment: completed example for welding and cutting

Why these controls

The fire hazard is controlled by a permit for every job. The permit is not paperwork for its own sake: it is the list of checks before the work starts, the fire watch during and after, and the isolation and reinstatement of any detectors. Most hot work fires happen where there was no permit and no watch.

Welding fume is a carcinogen and HSE expects extraction for all welding indoors, with respiratory protection where extraction cannot control it. The fume has its own COSHH assessment; this document records that it exists.

On customers' sites the firm works under the customer's permit system where one exists and issues its own where it does not. The assessment says which applies to each job.

Hazard descriptions and controls follow HSE guidance: HSE, Welding; HSE, Fire safety; HSE, Noise at work; HSE, Hand arm vibration; HSE, Manual handling at work; HSE INDG143, Manual handling at work: a brief guide; HSE, Electrical safety at work; HSE INDG236, Maintaining portable electric equipment in low risk environments. Checked 15 September 2026.

This document is a starting point. The employer must check it against the actual workplace, the product safety data sheet and current HSE guidance before relying on it. It is not an HSE approved document.

Risk assessment

Management of Health and Safety at Work Regulations 1999, regulation 3

Assessment numberRA-012

Revision1

Date of assessment15 September 2026

Last reviewed15 September 2026

Next review15 September 2027

Company or site	Merrick Fabrications Ltd
Activity	Hot works: welding, cutting and grinding
Location	Workshop at Unit 4, Bridge Road, and customers' sites by arrangement
Assessor	Tom Merrick
Reviewed by	Tom Merrick
Approved by	—

1. The activity

What is done	MIG and MMA welding, oxy fuel cutting and angle grinding of mild steel in the workshop and on customers' sites: repairs to gates, railings, steel frames and machinery.
Who does it, and who else could be affected	Three welders and an apprentice. Customers' staff on site jobs. Neighbouring units in the workshop block. Employees, Young or new workers, Contractors, Members of the public

2. Hazards at a glance

Hazard	Before controls	With controls
1. Fire and explosion from hot work	High 15	Low 5
2. Burns, eye damage and fume from welding and cutting	High 16	Low 6
3. Noise	Medium 12	Low 6
4. Hand arm vibration	High 16	Low 6
5. Manual handling of loads	Medium 9	Low 6
6. Electrical equipment and installations	Medium 10	Low 5

3. Hazards, who could be harmed and the controls in place

1. Fire and explosion from hot work

What could happen	Fire started by sparks, hot slag, flame or heat conducted through walls and pipes during welding, cutting, grinding, soldering or use of a blowtorch. Fires can start hours after the work has finished. Explosion if hot work is done near flammable liquids, gases or dust.
Who could be harmed	Welders, everyone in the workshop block, and on site jobs the customer's staff and building
Controls in place	Hot work is avoided where a cold method will do, for example mechanical cutting or push fit joints A hot work permit is issued for each job, stating the checks before, during and after Combustible materials are moved at least ten metres away or covered with fire resistant blankets, and openings are sealed A fire watch is kept during the work and for at least an hour after, with an extinguisher to hand Flammable liquids, gases and dust have been removed from the area, and containers that held them are checked before hot work Gas cylinders are secured upright, fitted with flashback arrestors, and hoses and regulators are checked before use Smoke detectors in the area are isolated only under the permit and reinstated afterwards On customers' sites the customer's permit system is used where one exists; otherwise the firm's own permit is issued by the lead welder
Risk before controls	High, 15 out of 25 (likelihood 3 × severity 5)
Risk with controls	Low, 5 out of 25 (likelihood 1 × severity 5)

Follows HSE, Welding; HSE, Fire safety.

2. Burns, eye damage and fume from welding and cutting

What could happen	Burns from sparks, spatter and hot metal; arc eye and retinal damage from ultraviolet light; lung disease from welding fume, which is a carcinogen; noise from grinding and cutting.
Who could be harmed	Welders and the apprentice, and anyone in the workshop without protection
Controls in place	Local exhaust ventilation captures welding fume at source, and RPE is worn where extraction cannot control it A COSHH assessment covers welding fume and any coatings on the metal Welding helmets or goggles with the right shade are worn, and screens protect people nearby from the arc Flame resistant overalls, gauntlets, leather apron and safety boots are worn, with no synthetic clothing underneath Grinder guards are fitted, discs are the right type and within date, and eye and hearing protection are worn Health surveillance is in place for regular welders
Risk before controls	High, 16 out of 25 (likelihood 4 × severity 4)
Risk with controls	Low, 6 out of 25 (likelihood 2 × severity 3)

Follows HSE, Welding. The substances involved need their own COSHH assessments.

3. Noise

What could happen	Permanent hearing loss and tinnitus from loud machinery, tools and music over time. Noise also masks warnings and alarms.
Who could be harmed	Everyone in the workshop when grinding or cutting is under way
Controls in place	Noise levels have been checked where staff have to raise their voices to be heard, and the results are recorded Hearing protection is provided, its use is required in marked zones, and staff have been shown how to wear it Time spent in noisy areas is limited by rotating tasks Hearing checks are arranged for staff regularly exposed above the upper action value
Risk before controls	Medium, 12 out of 25 (likelihood 4 × severity 3)
Risk with controls	Low, 6 out of 25 (likelihood 2 × severity 3)

Follows HSE, Noise at work.

4. Hand arm vibration

What could happen	Hand arm vibration syndrome and carpal tunnel syndrome from regular use of vibrating tools such as grinders, drills, breakers, sanders and strimmers. Permanent damage to nerves and blood vessels in the hands.
Who could be harmed	Welders using angle grinders for preparation and finishing, up to two hours a day
Controls in place	Low vibration tools are chosen, kept sharp and maintained, and the vibration data for each tool is known Daily trigger time is limited and tracked so exposure stays below the action value Tasks are rotated between staff and breaks are taken from vibrating tools Staff keep their hands warm and dry and know the symptoms to report Health surveillance is in place for staff regularly exposed above the action value
Risk before controls	High, 16 out of 25 (likelihood 4 × severity 4)
Risk with controls	Low, 6 out of 25 (likelihood 2 × severity 3)

Follows HSE, Hand arm vibration.

5. Manual handling of loads

What could happen	Back injury, strains and hernias from lifting, carrying, pushing and pulling loads that are heavy, awkward, or handled often. Musculoskeletal injuries build up over time as well as happening in one lift.
Who could be harmed	All staff moving steel sections, gas cylinders and welding sets
Controls in place	Trolleys, sack trucks or other lifting aids are provided and used for heavy or repeated loads Heavy loads are split into smaller ones or lifted by two people Staff who lift regularly have been shown how to lift safely and how to assess a load before they pick it up Heavy items are stored between knee and shoulder height, and the heaviest at waist height Cylinders are moved on a cylinder trolley, never rolled or carried
Risk before controls	Medium, 9 out of 25 (likelihood 3 × severity 3)
Risk with controls	Low, 6 out of 25 (likelihood 2 × severity 3)

Follows HSE, Manual handling at work; HSE INDG143, Manual handling at work: a brief guide.

6. Electrical equipment and installations

What could happen	Electric shock and burns from damaged leads, plugs and equipment, faulty installations or water near electrics. Fire from overloaded sockets and faulty equipment.
Who could be harmed	Welders using welding sets and grinders, on site sometimes in damp conditions
Controls in place	Staff look at plugs, leads and equipment before use and report anything damaged, which is then taken out of use Portable equipment is inspected and, where needed, tested at intervals that match how it is used, and the record is kept Equipment used outdoors or in wet areas runs through an RCD Only a competent electrician does repairs or alterations; staff do not open equipment or replace fuses without training Welding return clamps are placed close to the work so current cannot pass through structures or pipework
Risk before controls	Medium, 10 out of 25 (likelihood 2 × severity 5)
Risk with controls	Low, 5 out of 25 (likelihood 1 × severity 5)

Follows HSE, Electrical safety at work; HSE INDG236, Maintaining portable electric equipment in low risk environments.

4. Further action required

Noise: Look for ways to cut noise at source: quieter equipment, damping, enclosure or distance.Owner: ________. By ________
Manual handling of loads: Look at whether each regular lift can be avoided: deliveries to the point of use, smaller packs, or equipment moved by the supplier.Owner: ________. By ________
Manual handling of loads: Clear and shorten the routes loads are carried along.Owner: ________. By ________
Manual handling of loads: Check who is doing the lifting and take heavy loads away from anyone with a health reason not to lift.Owner: ________. By ________
Electrical equipment and installations: Book an inspection of the fixed electrical installation by a competent electrician.Owner: ________. By ________
Electrical equipment and installations: Remove daisy chained and overloaded extension leads and add sockets where they are needed.Owner: ________. By ________
Electrical equipment and installations: Move electrical equipment away from sinks and wet areas.Owner: ________. By ________
Fit on torch extraction to the second MIG set so both welding bays have extraction at sourceOwner: Tom Merrick. By 30 November 2026
Book baseline hearing and hand arm vibration health surveillance for all four staff with occupational healthOwner: Tom Merrick. By 31 October 2026

5. Notes

The apprentice does not do hot work on customers' sites and does not issue permits. Fire watch after hot work is one hour in the workshop and as the customer's permit requires on site, never less than an hour.

Hazard descriptions and controls drawn from HSE guidance: HSE, Welding; HSE, Fire safety; HSE, Noise at work; HSE, Hand arm vibration; HSE, Manual handling at work; HSE INDG143, Manual handling at work: a brief guide; HSE, Electrical safety at work; HSE INDG236, Maintaining portable electric equipment in low risk environments. This assessment follows the five steps in HSE guidance on risk assessment. It is a starting point; the employer must review it against the actual workplace before relying on it. Review by the next review date, and sooner if the activity, the equipment or the people doing it change, or after an accident or near miss.

Hot works risk assessment

Why these controls

1. The activity

2. Hazards at a glance

3. Hazards, who could be harmed and the controls in place

4. Further action required

5. Notes

Hazards in this assessment

Common questions

Other completed examples

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