MIG Welding FumeMIG welding of aluminium will produce particulate and gaseous welding fume. Particulate fume from aluminium MIG welding is made up mainly of aluminium oxide no matter which alloy is welded and whichever shielding gas is used. In general, as welding current increases so does fume generation rate. Gaseous fume generated by the MIG process may contain high amounts of ozone depending on the consumable composition, the shielding gas, and the welding current. Production of oxides of nitrogen gases is generally low. In general terms, more ozone tends to be generated using Al-Si filler wires than Al-Mg wires, pure argon shielding gas tends to produce more ozone than helium mixtures, and high current operation generates more ozone than low current. Ozone can be formed at considerable distance from the MIG arc. In terms of health and safety, the main hazard is ozone, and levels well in excess of exposure limits can be experienced. Control of exposure of welders and others is essential, and this will often involve the use of respiratory protection in addition to fume extraction.
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