Mobile and On-Tool Welding Fume Extraction: LEV for Site and Fabrication Work

Not every welder works at a fixed bench under a permanent extraction hood. Maintenance welders, site fabricators, mobile repair teams and one-person workshops weld in changing positions, on large structures, and in places where fixed LEV cannot reach. For them, controlling welding fume means portable and on-tool extraction — and the legal duties that come with it are exactly the same as for a fixed system.

This guide covers how mobile and on-tool LEV controls welding fume away from a fixed bench, and the COSHH obligations — including thorough examination and testing — that apply to portable equipment. For the wider picture of why all welding now needs fume control, see our guide to welding fume extraction requirements in the UK.

Why Mobile Welders Still Need Fume Control

The HSE's position on welding fume changed because the science changed. The International Agency for Research on Cancer reclassified all welding fume — including mild steel fume — as a cause of lung cancer. In response, the HSE strengthened its enforcement expectation: suitable engineering controls are required for all welding indoors, regardless of duration, because general ventilation does not achieve the necessary control.

That expectation does not stop at the workshop door or apply only to full-time bench welders. A maintenance welder who spends twenty minutes welding a bracket indoors needs fume control for that task. The phrase the HSE uses — "irrespective of duration" — is deliberate. A short job is not an exemption.

For welders who move from job to job, the practical answer is portable LEV: a mobile fume extraction unit, or extraction built into the welding torch itself.

Types of Mobile and On-Tool Welding LEV

Mobile (portable) fume extractors. These are self-contained units on wheels, with a flexible capture arm or hood that you position close to the weld. They draw fume into a filter and either recirculate cleaned air or discharge it. Their advantage is flexibility — you bring the extraction to the work. Their limitation is positioning discipline: a capture arm loses effectiveness fast as it gets further from the arc, so it must be repositioned for every weld.

On-torch (on-gun) extraction. For MIG and MAG welding, extraction can be built into the welding torch, drawing fume away right at the point it is created. On-torch extraction captures fume at source and moves with the welder, which removes the repositioning problem. It needs the right balance of extraction so it captures fume without disturbing the shielding gas.

On-tool extraction for associated tasks. Welding work often involves grinding, cutting and surface preparation that generate their own dust and fume. On-tool extraction fitted to grinders and cutters controls that exposure at source, in the same way it does for silica dust in construction work.

Portable LEV Is Still LEV Under COSHH

A mobile fume extractor and an on-torch extraction system are local exhaust ventilation. They capture a hazardous contaminant at source and remove it from the breathing zone. That means the full set of COSHH duties applies — the equipment being on wheels or built into a torch makes no difference.

Portable LEV must be:

• Suitable — the right capture rate for the welding process and consumables, with the capture device able to reach the fume
• Used correctly — switched on, positioned close to the arc, and repositioned as the work moves
• Maintained — filters monitored and replaced, capture arms and hoses kept in good order, airflow kept up
• Thoroughly examined and tested — at least once every 14 months under COSHH Regulation 9

The duty to use it correctly is especially important for mobile equipment. A fixed hood is always in the right place; a mobile arm is only effective if the welder actually positions it well, every time. Training and supervision matter more, not less, with portable LEV.

Thorough Examination and Testing for Portable LEV

COSHH Regulation 9 requires LEV to be thoroughly examined and tested at suitable intervals — at least every 14 months for most systems. Portable and on-tool extraction used routinely to control welding fume falls within this requirement.

A common misconception is that a portable unit, because it is "just a box on wheels," does not need a formal TExT. It does. The thorough examination checks that the unit is still capturing fume effectively — measuring extraction performance, checking the filter condition and the capture device — not simply confirming the fan runs.

Between formal tests, carry out and record regular user checks: is the airflow indicator showing adequate extraction, is the filter due for replacement, is the capture arm undamaged. Our guide on how often LEV must be tested explains the 14-month rule, and the LEV testing due date calculator tracks the next deadline for each unit.

The Record-Keeping Challenge for Mobile Operators

Mobile and multi-unit welding operations face a particular record-keeping problem. A single fixed system is easy to track. But a fleet of portable extractors — moving between sites, vans and welders — is easy to lose sight of. Each unit has its own 14-month test cycle, its own filter-change schedule, and its own user-check history.

When an HSE inspector or a client's safety auditor asks for evidence, "we have extraction" is not enough. You need to show, for each unit, a current TExT report, maintenance records, and user checks. Scattered paperwork across vans and sites is exactly the situation that leads to missed deadlines and failed inspections.

The record-keeping requirements checker sets out what you must keep, and the LEV log book guide explains why paper records fail for operations with equipment on the move.

Practical Compliance Steps

1. Inventory every extraction unit. List each portable extractor and on-torch system, where it lives, and which welders use it.

2. Control all indoor welding. Provide and use engineering controls for every indoor welding task, regardless of how short. Use the LEV compliance checklist generator to assess your setup.

3. Train welders to position capture. Mobile LEV only works if it is positioned close to the arc and repositioned as work moves. Make this part of welder training.

4. Put every unit on a 14-month test cycle. Each portable and on-torch system needs thorough examination and testing within 14 months.

5. Track filters and airflow. Falling extraction or a loaded filter means a unit is no longer controlling fume. Build filter checks into routine use.

6. Provide RPE for residual fume. Where engineering controls alone cannot control exposure — confined spaces, awkward positions — suitable, face-fit-tested RPE controls the residual risk.

7. Keep records per unit. A current TExT report, maintenance log and user checks for every extractor — not one folder for the whole fleet.

LEVproof is being built to help mobile and multi-site operators manage LEV compliance — tracking the 14-month cycle for every unit, storing reports, and reminding you before each deadline. Join the waitlist for early access.

Sources

• Control of Substances Hazardous to Health Regulations 2002 (COSHH) — legislation.gov.uk
• Change in Enforcement Expectations for Mild Steel Welding Fume — HSE
• Welding — health and safety — HSE
• HSG258: Controlling airborne contaminants at work — HSE
• COSHH main page — 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.