The composition and quality of welding fumes and gases are dependent upon the metal being welded. The process, procedure and electrodes used. Other conditions which also influence the composition and quantity of fumes and gases to which workers may be exposed include: coatings on metal being welded (such as paint, plating or galvanizing), the number of welders and the volume of the workers area, the quality and amount of ventilation, the position of the welder’s head with respect to the fume plume, as well as the presence of contaminants in the atmosphere (such as chlorinated hydrocarbon vapors from cleaning and degreasing activities). When the electrode is consumed, the fume and gas decomposition products generated are different in percent and form from the ingredients listed in Section II. Decomposition products of normal operation include those originating from the volatilization, reaction, or oxidation of the materials shown in Section 3, plus those from the base metal and coating, etc. as noted above. Reasonably expected fume constituents of this product would include: Primarily iron oxide and manganese oxides; secondary complex oxides of chromium, potassium, silicon and sodium.
The fume limit for Chromium, Nickel and/or Manganese may be reached before the general limit for welding fume of 5.0 mg/m3 is reached. Monitor fumes for Chromium, Nickel and Manganese.