The expertise of a welder cannot be understated, having to contend with a number of hazards on a continual basis requires extensive training. One such hazard that continues to blight the industry are welding fumes.
Having previously touched upon the physiological implications associated with welding fumes, we now turn our gaze towards the three classifications of filtration efficiency that surround them.
How Filtration Efficiency Is Classified
Referred to as ‘W classes’, these welding filter classifications have paved the way towards establishing a safer environment for welders in the workplace. These W classes scale linearly with the level of filtration, up to class W3 – the highest filtration efficiency.
In order to identify the filter performance required, it is a necessary prerequisite to identify the material being welded and the welding process.
Alloyed steels set the benchmark for welding filter classifications as, naturally, high-alloyed steels contain higher relative percentages of nickel and chromium, the main contributors towards carcinogenic fumes.
At a minimum, the performance of a welding filter must filter particle sizes of 100μm at a volume >10mg/m³. Conversely, maximal limits have also been established, whereupon particle sizes of 10μm at a volume >1.25mg/m³ must be filtered.
Types of W-Class
Regulations in place for welding fumes continue to grow more rigorous in an event to mitigate the risk of workers to carcinogenic compounds such as those containing chromium and nickel oxide.
The W-classes in question fall into three resolute categories with measurable parameters. They are as follows:
- W1 Class – Filtration efficiency to measure ≥95%. Suitable for unalloyed and/or low-alloyed steel.
- W2 Class – Filtration efficiency to measure ≥98%. Suitable for alloyed steels that contains ≤30% nickel and chromium.
- W3 Class – Filtration efficiency to measure ≥99%. Suitable for high-alloy steel that contains ≥30% nickel and chromium.
Why Rely on Filtration?
While a welder’s work environment can constantly shift, one thing that doesn’t shift is their exposure risk to the welding fumes in discussion. This is because ventilation systems are not an adequate method of diminishing these risks; filtration is the act of removing these contaminants, whereas ventilation simply seeks to relocate them.
In fact, poorly thought out ventilation systems can seek to exacerbate the issue at hand, allowing pollutants to settle onto areas they otherwise might not have been able to reach.
A welding filter system ensures that clean air is divided from almost all hazardous substances before being recycled back into the work area or outside. To comply with methods of best practice, it is recommended that filtration installations be surveyed once a year to ensure effectiveness.
We’ve been taking the safety of Canadian welders seriously for over 30 years at Dynamic Filtration. The filters we manufacture for welding purposes have been designed to keep not only your downtime to a minimum, but also your risk. Get in touch to weld better for longer!