The American Welding Society suggests that 90% of all welder emissions come from ____________________.

The American Welding Society suggests that 90% of all welder emissions come from ____________________.

• A. Shielding gas
• B. Electrodes
• C. Workpiece
• D. Fume collection system

Answer: (B)

The amount of welding fumes largely comes from the materials in the consumables, especially the electrode coatings and flux. When the arc heats the electrode, the flux and alloying compounds in the coating vaporize and form fumes that rise into the worker’s breathing zone. This is why electrodes are the biggest source of emissions: they bring with them the coatings and metals that become fumes as they melt and oxidize. Shielding gas mainly serves to protect the weld pool and does not contribute significant fumes, so it isn’t a primary emission source. The workpiece itself can contribute oxides, but its contribution to total welding emissions is much smaller in comparison to the electrode coatings. A fume collection system is a mitigation tool to capture fumes at the source, not a source of emissions.

The amount of welding fumes largely comes from the materials in the consumables, especially the electrode coatings and flux. When the arc heats the electrode, the flux and alloying compounds in the coating vaporize and form fumes that rise into the worker’s breathing zone. This is why electrodes are the biggest source of emissions: they bring with them the coatings and metals that become fumes as they melt and oxidize.

Shielding gas mainly serves to protect the weld pool and does not contribute significant fumes, so it isn’t a primary emission source. The workpiece itself can contribute oxides, but its contribution to total welding emissions is much smaller in comparison to the electrode coatings. A fume collection system is a mitigation tool to capture fumes at the source, not a source of emissions.