It appears that Chromium 6 is not only to be found in paints and coatings but also in certain types of welding fumes. This means that the health risks could be much greater than previously thought.
The last few years, more and more information about the dangers of chromium 6 (hexavalent chromium) in welding fumes has surfaced. It targets the respiratory system, liver, kidneys, skin, nose, and eyes, and is known to cause cancer and COPD1. Approximately 400,000 workers2 in the Netherlands regularly work in circumstances with welding fumes.
Exposure to chromium 6 in welding fumes is primarily associated with welding stainless steel. That doesn’t mean it is limited to this material. Usually, chromium is not added to other types of steel, but it can be around at low levels, due to the use of scrap steel in the production process. You will find exposure to welding fumes in multiple sectors. Workers in the metal industry, shipyards, construction work, and transportation sector are the possible prime victims.
Welders are not the only ones affected by the hazards of chromium 6. If there is no adequate exhaust ventilation and filtration in the workplace various other workers in the sectors mentioned above are at risk as well, like people who undertake cutting, grinding and sanding, or even forklift drivers, maintenance workers and team leaders.
In the Netherlands the maximum allowable concentration for hexavalent chromium is 1 µg/m3 for an 8-hr TWA exposure during a 40-hr workweek, for welding fumes in general this is 1 mg/m3.
In the USA the advice is more strict. The NIOSH recommends that airborne exposure to all Cr(VI) compounds be limited to a concentration of 0.2 µg Cr(VI)/m3 for an 8-hr TWA exposure during a 40-hr workweek3).
There are international standards for the preferred order to in which welding fumes must be captured. First reduction or avoidance of the production of welding fumes. Secondly at-source capture of welding fumes. Then separation of the source and human by automation and e.g. an extraction hood over the welding robot. When the previous is not possible or insufficient, e.g. because of very large work pieces, general ventilation and personal protection is recommended.
But equally important is the correct use of these extraction equipment by the workers and the maintenance of the system by the employer to keep the extraction as effective as anticipated.