Given the growing concern about welding fumes, it may be time to rethink your production systems
Welding fumes can be vicious. Short-term exposure often results in nausea, dizziness, and irritation to the eye, nose and throat. Long-term exposure has been shown to cause cancers of the lung, larynx and urinary tract, asthma, nerve damage and kidney problems. With the country's Health and Safety Executive (HSE) joining its voice to the chorus of legislators demanding tighter controls, it's a good moment for UK companies to think about reducing their employees' exposure... even if that involves a wholesale rethink of their production systems.
Understanding the threat
Welding requires your employees to heat metals to melting point. That's an intense process which results in metals being released in to the air in gaseous and vapour form. Although relatively little metal enters the atmosphere in this fashion, the small amount which does is highly reactive and thus extremely dangerous.
Legislators worldwide are increasingly conscious of the health risks posed by welding fumes. UK businesses should be aware that the HSE began issuing health alerts on this subject and that all emissions of welding fumes are subject to the Control of Substances Hazardous to Health (COSHH) Regulations. Employers are legally obliged to provide protection to workers who might be affected.
What is to be done?
One of RentArc's specialisms is the supply of fume extraction equipment. Properly-deployed extractors can significantly reduce welding fume exposure, so this article will provide a brisk introduction to the topic.
Before discussing fume extractors, however, we'll echo HSE's advice: fume reduction requires a rethink of the entire production process. This may involve any or all of the following:
* Maintaining control measures and good general ventilation
* Reassessing working practices
Could your welding processes be automated? Could you switch to distance or enclosed welding, or convert from stick to MIG processes? (This might be a good time to call in a consultant!)
* Issuing correct respiratory protective equipment (RPE) and personal protective equipment (PPE)
COSHH regards RPE and PPE issues as a fallback. If you don't have any other measures in place, you're obliged to provide them. In practice, as we'll see later, it's usually a good idea to have suitable PPE and RPE available.
* Setting up local exhaust ventilation (LEV)
LEV, also known as fume extraction, uses filtration systems to remove fumes at their source. Such systems can be very effective, but one size doesn't fit all. It's important to choose an LEV system that suits your workflow. The next section introduces the four commonest forms.
A closer look at LEV
LEV removes contaminated air at source. The four commonest forms of LEV are:
* Mobile extraction units
* Fume torches
* Extraction tables
* Engineered solutions
Mobile extraction units
Mobile extraction units are portable devices, either mounted on wheels or light enough to be carried. The operator positions a hood attached to the unit at the workpiece, enabling the inbuilt suction fan to draw foul air from the workpiece through a filtration system before releasing it. Mobile extractors are the least expensive fume extraction option and have the advantage of flexibility, enabling them to be deployed as needed. At RentArc, we take this to its logical conclusion by renting portable fume extractors.
Torch fume extraction relies on specially-made welding torches with extraction ports at the head connected to outboard suction mechanisms. These are intended to be in operation whenever the torch is switched on, so that any fumes generated are immediately removed for filtration. Once installed, such systems can be very effective, but they require complete retooling, and the necessity of attaching a suction hose to the torch may make the process of welding more awkward.
Extraction tables are welding benches with inbuilt air filtration. They're suitable for a number of machine tool operations including grinding and plasma cutting as well as welding. Although such devices can be placed anywhere, they're normally installed inside welding booths so as to minimize the release of fumes through the workshop.
Engineered solutions, also known as multi-arm systems, are large-scale suction systems designed to filter the air of an entire workshop. One or more arms with extraction ports will be positioned at each workplace, typically arranged as a row of welding booths, with additional extractors positioned as required, all connected to a single high-powered filtration/ventilation system. Such solutions are extremely effective, but best-suited for factory-type operations with predictable work patterns.
Falling back on RPE
There is no universally-applicable fume extraction solution, and, even using a combination of the methods set out above, some workshops will find it difficult to achieve a satisfactory reduction in fume exposure. This is particularly true when shops are obliged to reorganise their workflows in order to accommodate the demands of particular tasks.
Employers should always make sure that they are issuing appropriate PPE and RPE. Air-fed helmets are a widely-accepted 'first line' defence against fumes and ensuring their availability to staff will go some way to forestalling the problems arising from a hasty setup – but mobile extraction such as Plymovent’s Mobile Go or MFD Extractor may represent a more practical solution!
Keeping Welders Welding