Particulate fume

From GAWDAwiki

Particulate fume is the discrete solid particles produced during welding and cutting. It consists of the complex oxides and silicates of metals in the parent plate and filler wire, which are generally under 0.5 microns in diameter. This falls into the "respirable" size range, meaning that the particles can be breathed in and reach the lungs.^[1]

References

1. http://www.bocindustrial.co.uk/bocindustrial/technical/glossary/a.asp