Welding and cutting torch fumes — extraction and respiratory protection in the metalworking shop

When metal is heated, soldered, or welded, particles and gases are released into the air—what we collectively call fume. On a metal shop, daily exposure to this fume is one of the most important workplace health risks. The fume isn't always clearly visible, but it penetrates deep into the airways, and over time it can cause serious and lasting illness. That's why controlling fume isn't optional but a basic requirement of the trade.

§What does the smoke contain?

Air pollution from welding and cutting processes consists of both particles (smoke) and gases. The composition depends on the metal, the filler material and the process. When soldering, the flux and solder — e.g. zinc from brass or lead-containing solder — contribute to the smoke. When welding in alloy steel, compounds such as chromium and nickel compounds may be released. According to industry guidelines, welding fume is the most common cause of reported respiratory diseases in the metal and machinery industry.

§Extraction rather than mask.

Occupational health and safety rules are based on a prevention hierarchy: technical solutions take precedence over personal protective equipment. In practice this means smoke must be removed at the source with process extraction — e.g. an extraction arm or low-pressure extraction close to the solder point — before it reaches the airways. Contaminated air must not be recirculated back to the work room. Only when source extraction is insufficient is it supplemented with respiratory protection.

§Limit values and ventilation

The Labour Authority sets limit values — the highest permitted average concentration of a substance in the air over an 8-hour workday — in the regulation on limit values for substances and materials. In addition to source extraction the workshop must have effective room ventilation that removes small scattered pollutants. Ventilation must supply clean replacement air so extraction can work.

How you prevent pressure sores

• 01Always use process extraction as close to the smoke source as possible
• 02Place head outside smoke plume — do not lean over the workpiece
• 03Choose lead-free solder and low-zinc processes where possible
• 04Supplement with appropriate respiratory protection (e.g., P3 filter) in case of heavy smoke
• 05Provide clean replacement air and avoid recirculation of extracted air
• 06Maintain the extraction system so the suction remains effective

Respiratory protection: the last resort

Respiratory protection is not a substitute for exhaust ventilation, but a supplement when exhaust ventilation cannot reduce contamination sufficiently. The protection must fit the contamination (particle filter against smoke particles) and the wearer, and it can only be worn for as long as work requires, as it strains breathing. If choosing filtering respiratory protection, it must fit tightly — beards and glasses can break the seal.

“The smoke you can't see is often the one that does the most damage — remove it at source.”