The Health Risk of Ultraviolet Radiation and Its Intensity in Shielded Metal Arc Welding

In gas-shielded arc welding, selecting the appropriate gas mixture is crucial not only for welding quality but also for reducing harmful UV radiation, which poses an occupational health risk. The aim of this research was to investigate the intensity of UV-A and UV-B radiation (290–390 nm) in the low-current range (10–45 A) using pure argon (Ar), helium (He), nitrogen (N₂), and a 70% Ar / 30% He gas mixture. The measurements demonstrated that the composition of the shielding gas drastically affects UV emission. Under identical parameters, pure argon generates around three times higher radiation levels than pure helium. But when 30% helium was added to argon, the UV emission was significantly reduced by approximately 30%. The highest UV values were recorded with pure nitrogen. The tests revealed that the main reason is severe arc instability: the expanding plasma surface area significantly increases radiation. Overall, it can be concluded that in the low-current welding range, arc stability determines the magnitude of UV radiation to a greater extent than the emission characteristics of the gases. However, further measurements are needed to draw conclusions for higher amperages.