Manganese and hexavalent chromium

Protection against manganese and hexavalent chromium

Welding fumes are very fine solid metal particulates. Welding fumes are formed when metal is heated above its boiling point generating vapours which quickly goes through the deposition process to become particulate. Welding fumes are mainly composed of metal oxide particles from the metal being welded and from the electrode being consumed (but this may vary depending on the process).

Stainless Steel: Welders use many different names when referring to this type of metal: alloy steel, mangalloy steel, mixed steel, inox steel, austenitic stainless steel and may call it coated steel or even galvanized steel (although galvanized steel is covered with zinc oxide where stainless has chromium in it to prevent oxidation or “rusting”, for example). Stainless steel is used in a multitude of different applications in everything from housewares to larger welded items like cars, oil and gas platforms, ships, bridges or water and sewage piping. A major hazard to a welder are the fumes generated when welding (the majority of which cannot be seen with the naked eye). Two of the most common fume exposures while welding on stainless steel are manganese and hexavalent chromium. Most carcinogens are classified based on evaluations made by the International Agency for Research on Cancer (IARC). Hexavalent chromium is a known carcinogen (IARC 1) and there is a well-established link between hexavalent chromium exposures and lung cancer.

Mild Steel: Mild steel has a much lower chromium content than stainless steel. Unlike stainless steel, mild steel will rust when exposed to moisture and air. Fumes from mild steel welding contain mainly iron with small amounts of additive metals (chromium, nickel, manganese, molybdenum, vanadium, titanium, cobalt, copper etc.). The International Agency for Research on Cancer also classifies welding fumes and UV radiation from mild steel welding as known carcinogens (IARC 1).