Welding Risk Assessment
Welding Fumes · Welding Fumes overview
A welding risk assessment is the structured COSHH review of the welding processes, metals, consumables and working environment that determine welder exposure to fume — and of the controls in place to keep that exposure adequately controlled. It is the document that sits beneath every other welding fume control decision an employer makes.
What a welding risk assessment reviews
Under COSHH Regulation 6, employers must assess the risk created by exposure to hazardous substances arising from work activities. For welding, that means a substance-aware review of the welding fumes generated by each process and parent metal in use, the workers exposed, the controls in place to capture or dilute fume, and the residual risk after those controls. The assessment is the basis on which decisions about exposure monitoring, LEV provision, RPE specification and welder training are justified.
A welding risk assessment is not a generic template completed once. It is reviewed when processes, metals, consumables, workforce, layout or controls change, and at intervals appropriate to the work — the HSE expectation since 2019 is that welding fume risk assessments are revisited in light of the carcinogen reclassification.
Risk assessment vs fume monitoring, air sampling and LEV review
These four activities support each other but are not interchangeable. The welding risk assessment is the overarching document; fume monitoring and air sampling are the measurement activities that characterise actual breathing-zone exposure; LEV testing is the engineering examination of the extraction system itself.
- Welding risk assessment — substance, process, control and residual-risk review under COSHH.
- Welding fume monitoring — measured 8-hour TWA exposure vs EH40 WELs.
- Welding air sampling — the technique used to collect the monitoring sample.
- Welding LEV testing — Thorough Examination and Test of extraction under COSHH Reg 9.
Processes, metals, coatings and consumables
Welding fume composition is driven by what is being welded and what is being used to weld it. A useful risk assessment captures the welding process (MIG/MAG, MMA, TIG, FCAW, plasma, oxy-fuel), the parent metal grade, any coatings present (galvanised, painted, primed, oiled) and the specific consumable composition. The same welder, working on the same bench, can present materially different exposure profiles between consumables — particularly for manganese, hexavalent chromium and nickel.
Adjacent activities are equally relevant. Grinding, gouging, brazing and oxy-fuel cutting generate their own metal aerosols. Where these activities share a workshop with welding, the assessment should consider combined exposure rather than treating each in isolation.
Work location and arrangement
Where welding takes place influences exposure as much as how it is done. The risk assessment should consider whether welding is bench-based, in-position on a structure, overhead, in a confined space, outdoors with cross-wind, or in a fabrication cell with adjacent welders. Confined-space welding raises distinct issues including oxygen displacement by shielding gas, accumulation of fume in poorly ventilated volumes, and access constraints that complicate emergency response.
Control review — extraction, ventilation, RPE and work methods
The control review sits at the heart of the welding risk assessment. The COSHH hierarchy is applied in order: elimination or substitution (lower-fume process, lower-emission consumable, lower-coating workpiece), engineering controls (on-torch extraction, hood LEV, downdraft bench, central LEV), administrative controls (work patterns, rotation, segregation of fume-generating tasks), and finally RPE.
- Source capture — on-torch extraction or capture hoods within the recommended capture envelope.
- Workshop ventilation — general dilution to control residual and drifted fume.
- RPE — face-fit tested half-mask or PAPR matched to the metal WELs of concern.
- Work methods — torch angle, body position and welder training to keep the plume out of the breathing zone.
- Supervision and monitoring — checks that controls are used and maintained.
- LEV maintenance — filter changes and Thorough Examination and Test under COSHH Reg 9.
Common risk indicators
Several recurring indicators in a welding risk assessment suggest that exposure may not be adequately controlled and that welding fume monitoring is warranted. None of them is conclusive on its own, but they shift the balance of evidence under COSHH.
- Visible blue or grey fume layer at head height in the welding bay.
- Welders reporting metallic taste, throat irritation, cough or metal fume fever.
- On-torch extraction routinely disconnected, blocked or running on a clogged filter.
- Stainless steel or nickel-alloy welding introduced without re-assessment.
- Galvanised or painted workpieces welded without coating removal or extraction upgrade.
- RPE used inconsistently, without face-fit testing, or worn over facial hair.
- Welding LEV with no record of Thorough Examination and Test in the last 14 months.
How findings support proportionate control decisions
A welding risk assessment is only as useful as the actions that flow from it. Findings should support proportionate, prioritised control change — starting with the residual risks of highest consequence (stainless steel and nickel-alloy welding, sustained mild steel welding indoors, confined-space welding) and the controls most likely to reduce exposure (source capture, consumable selection, LEV maintenance) before secondary measures (RPE specification, work pattern adjustment).
Where the assessment cannot reasonably conclude that exposure is adequately controlled, welding fume monitoring is the appropriate next step. The monitoring results then feed back into the assessment, closing the loop between the documented risk position and the measured reality on the workshop floor.
Frequently asked questions
Who should write a welding risk assessment?
A welding risk assessment should be written by someone competent in COSHH risk assessment for welding fume specifically. That usually means an occupational hygienist, a welding-experienced H&S manager, or an external specialist working with the welding supervisor and the workshop team. Competence — not job title — is the COSHH test.
How often should a welding risk assessment be reviewed?
There is no fixed interval, but COSHH requires review whenever there is reason to suspect the assessment is no longer valid, or when there has been a significant change in work. For welding, that includes new processes, new parent metals, new consumables, layout changes, workforce changes and changes to extraction or ventilation. Periodic review every 12–24 months is common practice.
Does a welding risk assessment have to include monitoring?
Not necessarily. The assessment determines whether monitoring is required. Where exposure can reasonably be concluded to be adequately controlled without measurement — for example minimal arc-on time outdoors with effective source capture — monitoring may not be needed. Where this cannot reasonably be concluded, exposure monitoring is the route to a defensible position under COSHH.
What standards underpin a welding risk assessment?
The principal framework is COSHH (Control of Substances Hazardous to Health Regulations) supported by HSE EH40 (Workplace Exposure Limits) and BS EN 689 (strategy for comparison with limit values). Welding-specific HSE guidance — including the 2019 Safety Alert on welding fume reclassification — sets current expectations for control and assessment.
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