Energy efficiency is the most important factor for reducing environmental impact from welding equipment. Welding consumables on the other hand, generates welding slag, fumes and/or stub ends depending on type of consumable. The analysis of welding slag depends on the consumable used, but CaF2 and oxides of Ca, Mg, Al, Mn, Ti, Fe, Si are common components. When welding high alloyed steel, oxides of Cr and/or Ni are also present. We have made studies on leaching of metals and fluorides from slags under different conditions. These studies shows that leaching is slow but does occur. Welding fumes may be hazardous and should be kept away from the welders breathing zone. Fume components contributing to the health hazard are mainly heavy metals and fluorides. This is discussed in more detail in the publication Welding and Cutting - risks and measures.