Welding Fume: Precision Sheet Metal Case Study


The Client

An engineering business, who specialises in the manufacturing of bespoke precision sheet metal products and engineering projects. Auto Extract Systems were tasked with proposing and installing a comprehensive LEV (local exhaust ventilation) system in the fabrication workshop to safely capture and remove the welding fumes that are emitted into the workplace’s air during the businesses’ operations. The LEV system was installed as part of a project to ensure the site meets stringent operational requirements to work strictly in accordance with HSG258: Controlling Airborne Contaminants at Work: A Guide to Local Exhaust Ventilation (LEV) guidance.

The Challenge

The precision sheet metal company had no form of LEV (local exhaust ventilation) in their welding workshop and were aware they needed to improve the air quality for staff, particularly so after HSE issued a new safety alert about a change in enforcement expectations for the fumes created by the welding of mild steel.

The change in enforcement expectations for mild steel welding fume have been brought in after new scientific evidence from the International Agency for Research on Cancer came to light that exposure to mild steel welding fumes can cause lung cancer, possibly kidney cancer and neurological effects similar to Parkinson’s disease in humans. As a result, the Workplace Health Expert Committee has endorsed the reclassification of mild steel welding fume as a human carcinogen. The reclassification will see HSE’s enforcement expectation for mild steel welding fumes come into force with immediate effect; primarily because general ventilation does not provide the necessary control required to safely protect workers.

The Solution

The solution was proposed and agreed to supply and install new galvanised steel ducting and fittings to accommodate 10 four-metre-long 160mm diameter fume hose extraction arms, complete with a metallic fume capture hoods. The extraction arms installed provided the business with 25% increased airflow over a traditional-styled internal knuckle extraction arm, as they feature an externally mounted supports, which reduce static pressure airdrops. Each point was connected to a common duct that ran to a centrifugal fan, which was ducted outside and turned upwards to vent the air to the atmosphere through a high-velocity cowl.

When assessing the businesses fabrication workshop, the client stated the LEV system was exclusively for the safe capture and removal of welding fume, however, there was the potential to increase the grinding processes, which would change the LEV system’s purpose. With this in mind, the extraction fan that was specified for the client was upgraded to accommodate higher airflows should a filtration unit be required to be retrofitted into the system. The fan specified also exceeds the E.U Directive 2009/125/EC ErP, which is aimed at reducing CO² emissions by 20% by using energy-efficient motors in conjunction with industry-leading blade design.