SAW welding, or also automatic submerged welding is a very effective and high-quality method at all. It is characterized by minimal emissions and UV radiation. In fact, it is welding with the help of an electrical arc by a consumable electrode. The electrode is a form of a rod wound on a coil and with the help of electric motor-driven pulleys, it is moved into a burning arc.
The principal difference between MIG/MAG and SAW methods is in a protective weld pool against oxidation (air access). For MIG/MAG methods the protection is provided by shielding gas, while for flux welding, powdered flux provides protection.
The weld pool is constantly covered with the flux during welding, so the arc is not visible at all, it is hidden under the layer of the flux and thus it becomes minimally harmful (emissions, UV radiation).