Welding Fume Extraction Requirements UK: What Changed and What You Must Do

In 2019, the HSE changed its enforcement position on welding fume. The change was significant. Before 2019, mild steel welding in a well-ventilated area was generally considered acceptable without local exhaust ventilation. That's no longer the case.

If you carry out any welding — mild steel, stainless steel, aluminium, anything — you now need effective fume extraction. General ventilation alone is not sufficient.

What Changed in 2019

The shift came after the International Agency for Research on Cancer reclassified mild steel welding fume as a human carcinogen. Previously, only stainless steel and high-alloy welding fume carried that classification. The reclassification meant that all welding fume — regardless of the base metal — is now recognised as causing lung cancer.

The HSE responded by updating its enforcement expectations. The key changes:

• All welding fume is now treated as a carcinogen. This applies to MIG, TIG, MMA, flux-cored, and every other process.
• The workplace exposure limit for all welding fume is 1 mg/m³ (respirable dust, 8-hour TWA) under EH40. For specific components like manganese in the fume, the limits are even lower.
• General ventilation is not sufficient as the sole control measure. The HSE's position is that LEV, on-tool extraction, or respiratory protective equipment (RPE) is required for all indoor welding. LEV is the preferred control under COSHH's hierarchy.
• Outdoor welding still requires controls. Even outdoors, welders need RPE unless a risk assessment demonstrates that exposure is controlled below the WEL.

This wasn't a change in the law. The COSHH Regulations already required employers to control exposure to hazardous substances as far as reasonably practicable. What changed was the HSE's interpretation of what "reasonably practicable" means for welding fume — and the enforcement stance that followed.

HSE's Enforcement Position

The HSE adopted a zero-tolerance approach to welding fume exposure from 2019 onwards. Inspectors visiting welding workshops expect to see engineering controls in place. The HSE's welding guidance makes the position explicit.

In practice, this means:

• Indoor welding without LEV or RPE will result in enforcement action. An improvement notice is the minimum. Prohibition notices — stopping the welding operation entirely — are issued where the risk is immediate.
• "We've always done it this way" is not a defence. The reclassification applies retrospectively to exposure assessment. If your risk assessment still says mild steel welding fume is low risk, it's out of date.
• The HSE checks both the control measures and the records. Having extraction fitted isn't enough. You need evidence that it works, that it's maintained, and that it's tested under COSHH Regulation 9.

Types of Welding Fume Extraction

The right extraction method depends on your workshop layout, the type of welding, and where the work happens.

On-torch or on-gun extraction

A shroud fitted around the welding torch captures fume at the point of generation. The fume is drawn through a hose built into or attached to the torch assembly, then filtered.

This is the most effective capture method because the extraction point travels with the arc. It works well for MIG welding in fixed positions and on production lines. The trade-off is that the torch is heavier and bulkier, which matters for manual welding over long shifts. Some welders resist using them for this reason — but the legal position is clear: comfort preferences don't override health protection duties.

Flexible arm extraction

A flexible or articulated arm with a capture hood, positioned near the welding point. The welder adjusts the arm as they move along a joint. These are the most common LEV solution for general fabrication shops.

Effective capture depends on correct positioning. The hood should be within 300mm of the welding point, on the opposite side from the welder. Too far away and the capture velocity drops rapidly — fume escapes into the workshop. Too close and it disturbs the shielding gas.

Training matters here. A flexible arm system is only as good as the welder's discipline in repositioning it for each weld.

Downdraft benches

A workbench with an integrated extraction surface that draws fume downwards, away from the welder's breathing zone. Suited to smaller work that can be placed on the bench — short fabrication pieces, brackets, small assemblies.

Downdraft benches are effective for their designed purpose but won't work for large fabrications, overhead welding, or work that can't be positioned on the bench surface. They're a solution for specific applications, not a universal answer.

Fixed or semi-fixed hood systems

Canopy hoods or side-draft hoods installed over fixed welding stations. These work best where the welding happens consistently in one location and the work piece doesn't vary much in size.

Their capture effectiveness reduces quickly with distance. A canopy hood more than about 1 metre above the welding point will capture very little fume before it disperses.

What general ventilation cannot do

Opening the roller shutter doors and running a roof fan is general ventilation. It dilutes fume throughout the workshop but doesn't capture it at source. Under the HSE's current enforcement position, this is not an acceptable primary control for any indoor welding operation.

General ventilation has a role as a supplement — it helps manage background fume levels and residual fume that escapes capture. But it cannot replace LEV.

Specific LEV Requirements for Welding Workshops

Once you have extraction in place, the COSHH duties apply in full:

Maintenance. Under Regulation 9, welding fume extraction must be maintained in efficient working order and good repair. Filters clog, flexible arms lose their positioning tension, hoses crack. A maintenance schedule between inspections is essential — not just reactive repairs when something obviously breaks. See HSG258 for practical maintenance guidance.

Thorough examination and testing. Your welding fume LEV must undergo a TExT at least every 14 months. The examiner will measure capture velocities, assess filter performance, and check the system against its design specification. Check our due date calculator to track your testing schedule.

Record-keeping. TExT reports must be retained for 5 years. Maintenance and user check logs should be kept alongside them. Use our record-keeping requirements checker to confirm what you need to retain.

User checks. Daily checks before welding starts: confirm extraction is running, position flexible arms correctly, check for visible fume escape during the first welds of the day.

Common Compliance Gaps in Welding Shops

These are the issues the HSE finds most frequently:

No extraction at all. Still the most common finding, especially in smaller fabrication shops. Some businesses haven't updated their approach since before 2019.

Extraction fitted but not used. The flexible arm is pushed out of the way. The on-torch extraction is disconnected. The system is switched off to save energy. All of these leave the welder exposed and the employer in breach.

Extraction fitted but positioned incorrectly. The flexible arm hood is too far from the welding point. A difference of 200mm in hood position can halve the capture efficiency. Welders need training on correct positioning — and supervision to ensure it happens.

Outdated risk assessment. The COSHH risk assessment still reflects the pre-2019 position on mild steel welding fume. If your assessment doesn't identify mild steel welding fume as a carcinogen and specify LEV as a required control, it needs updating immediately.

No TExT records. The extraction system may be working perfectly, but without a current thorough examination report, you can't demonstrate compliance. The 14-month testing cycle is a legal requirement, not a recommendation.

RPE not provided as backup. Even with good LEV, some welding operations — confined space work, awkward positions where the arm can't reach, outdoor welding — need RPE as well. Your risk assessment should identify when RPE is required in addition to LEV.

Getting Compliant

If your welding workshop doesn't currently have adequate fume extraction, act now. The HSE's enforcement stance is established and consistent. The steps:

1. Update your COSHH risk assessment to reflect the carcinogenic classification of all welding fume.
2. Assess your extraction needs based on the type of welding, workshop layout, and work patterns.
3. Install appropriate LEV — on-torch, flexible arm, downdraft bench, or a combination.
4. Train all welders on using the extraction correctly and repositioning it for each weld.
5. Set up maintenance and user check schedules.
6. Arrange your first TExT within 14 months of installation.

You can start with a tailored compliance checklist using our LEV compliance checklist generator.

Tracking It All

Managing fume extraction compliance across multiple welding bays, each with its own TExT schedule and maintenance log, takes organisation. LEVproof is built to keep welding shops audit-ready without the paperwork burden. Join the waitlist for early access.

Sources

• Control of Substances Hazardous to Health Regulations 2002 (COSHH) — legislation.gov.uk
• HSE welding guidance — HSE
• HSG258: Controlling airborne contaminants at work — HSE
• LEV guidance for employers — HSE
• COSHH main page — HSE
• Work-related lung disease — HSE

This guide summarises published HSE and government guidance. It does not constitute legal advice. Consult a qualified professional for advice specific to your situation.