A repair takes ten minutes, the workshop door is open and the welder has a visor. None of those facts proves that breathing exposure is controlled. HSE says all welding fume can cause lung cancer, including fume from mild steel. COSHH duties apply to occasional welding as well as specialist fabrication. The assessment must explain how this particular job will be controlled, not simply record that welding happens on the premises.
Assess the job, not just the welding machine
Start with the process, parent metal, consumable, coatings and contamination. Include preparation and finishing where they introduce separate exposures. HSE identifies both particles and gases as potential respiratory hazards; for example, galvanised-metal work is associated with metal fume fever, while some welding processes generate ozone. A generic entry labelled 'metal fume' can hide important differences.
Record how often welding happens, its duration, the workpiece size, working position and location. Then walk the surrounding area: who is assembling parts, cleaning, supervising or passing through? Give the assessor a realistic picture of the busiest combination of jobs, rather than demonstrating a single quiet weld after everyone else has left.
For a Teesside fabricator, a change from small bench assemblies to large frames can alter where people stand and whether extraction reaches the weld. For a vehicle workshop, an occasional repair becoming a daily service changes the basis of the original assessment. Treat those changes as decisions to review, not administrative details.
HSE: welding fume duties and health risks ↗ · HSE: health risks from welding ↗
Reduce the fume before relying on personal protection
First consider whether the joint can be made without welding, or with less welding or a lower-fume process. Any alternative still needs to meet the engineering specification and have its own risks assessed. Do not substitute a different process simply because its plume looks smaller.
For indoor welding, HSE's general approach is source capture using local exhaust ventilation, backed by suitable respiratory protection where exposure is not adequately controlled. Choose extraction around the job: on-torch capture, a bench, a booth or a movable hood may suit different work. The control must function while the weld progresses, not only at the starting position.
Arrange a practical demonstration using representative workpieces before committing to equipment. Ask the operator to show the awkward seam as well as the easy one. Record the arrangement that works, its limitations and who authorises a different setup. Our separate LEV guide covers the maintenance and examination system in more detail.
HSE: avoid or reduce welding-fume exposure ↗ · Related guide: managing LEV →
Understand the limited provision for sporadic welding
HSE's detailed guidance says engineered fume controls will not normally be expected for occasional welding carried out less than once each week and lasting less than one hour. In that situation it still requires suitable RPE and good general ventilation, with protection for other people nearby. This is guidance on proportionate controls, not an exemption from COSHH or a safe-exposure threshold.
Do not stretch 'occasional' to cover regular production or several workers doing repeated repairs. Document the actual pattern and review it when workload changes. If the task does not fit the guidance, or protection of nearby people is uncertain, obtain competent advice on the control arrangement rather than treating a stopwatch as the assessment.
HSE: controlling welding risks, including sporadic welding ↗
Review the welding task before relying on yesterday's controls.
HR + SAFETY can help assess the work pattern, identify gaps in COSHH arrangements and coordinate specialist extraction or occupational hygiene input where needed.
Discuss welding-fume controlsSelect RPE for the contaminant, person and duration
HSE requires suitable RPE for outdoor welding because LEV cannot be relied on to capture the fume effectively. Indoors, residual exposure may also require RPE. A welding visor alone is not respiratory protection. Selection must cover the actual contaminants: particulate filters do not protect against welding gases.
HSE's general advice identifies FFP3 or half-mask/P3 protection for short-duration work and powered air-fed protection with at least APF20 for longer work. These are not universal purchasing instructions: check suitability for the task and wearer. Tight-fitting facepieces need face-fit testing and a clean-shaven sealing area; assess compatibility with the welding helmet and other protection.
Make charging, spare filters, cleaning and storage part of the job plan. A technically suitable unit is ineffective if its battery is flat or it is lifted during exposure. Confined-space welding needs a separate, competent assessment; this workshop guide is not an entry procedure.
Check performance and act on defects
Train operators to position the hood, stay within its effective capture zone and keep fume away from their breathing zone. Include a demonstration of what to do when extraction fails or a task no longer fits the agreed setup. Supervisors should observe the work, not rely solely on a signed training sheet.
HSE calls for daily damage checks, prompt repairs and competent LEV thorough examination and testing at least every 14 months, with examination and test records kept for at least five years. Routine checks and maintenance remain necessary between examinations. Stop affected work when its required controls are unavailable, and verify the repair before restarting.
HSE: welding-fume training ↗ · HSE: maintaining exposure controls ↗
Decide health surveillance and link the other risks
Health surveillance follows the assessment; it does not replace exposure control. HSE recommends respiratory health surveillance for stainless-steel welding where an asthmagen such as chromium is present, unless the assessment shows no reasonable likelihood of asthma developing. A competent occupational health provider should advise on the programme and response to symptoms.
New or changed welding also introduces fire considerations. The responsible person must review and update the statutory fire risk assessment where the change affects it. If existing coverage is inadequate, complete a linked welding/hot-work assessment and incorporate its findings into the main FRA, emergency arrangements and controls. Consider vulnerable occupants and adjacent sleeping or care premises, where consequences may be greater. A fume assessment or hot-work permit does not replace the FRA.
HSE: welding health surveillance ↗ · GOV.UK: fire risk assessment responsibilities ↗ · Related guide: hot-work controls →
Before-work decision checklist
Legal claims and official guidance checked on 16 October 2026. This guide addresses current Great Britain health-and-safety duties, with fire guidance relevant to premises in England. It does not announce a new law or replace a competent, task-specific assessment.
- Identify the process, metal, consumable, coatings and relevant exposures.
- Confirm the real frequency, duration, location and people affected.
- Consider avoidance, reduction and suitable source capture.
- Verify any reliance on the narrow sporadic-welding guidance.
- Select suitable RPE and confirm fit, compatibility and readiness.
- Show operators the controls, limitations and stop-work response.
- Arrange maintenance, examination and any required health surveillance.
- Review linked fire precautions and reassess when the work changes.
A welding fume risk assessment must lead to controls that work during the real job. Short duration does not remove the duty to protect the welder or the people nearby.
This guide provides general information for UK employers. It is not legal advice and should not replace advice based on the facts of a specific matter.