Definition(s)
Fume
Small diameter particulate matter formed when vaporized high molecular weight materials condense from the gaseous state. Although solids, fumes are small enough to behave like gases.
API RP 2009, Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries, Seventh Edition, February 2002 (Reaffirmed, March 2012), Global Standards