Ultrafine Particles Emitted by Flame and Electric Arc Guns for Thermal Spraying of Metals

The ultrafine aerosol emitted by thermal spraying of metals using flame and
electric arc processes has been characterized in terms of particle size
distribution and emission rates based on both particle number and mass. Thermal
spraying of Zn, Zn/Al, and Al was studied. Measurements taken using an
electrical low pressure impactor and a condensation nucleus counter reveal an
aerosol made up of very fine particles (80-95% of number distribution <100 nm).
Ultrafine particle emission rates produced by the electric arc process are very
high, the largest values being recorded during spraying of pure aluminium. This
process generates high particle emissions and therefore requires careful
consideration and possible rethinking of currently implemented protection
measures: ventilated cabins, dust collectors, and personal protective

More info - Source: Annals of Occupational Hygiene