Weld spatter properties and ways of spatter formation were analyzed in the article. It was deter-mined that solidified spatter can be considered as an active agent in environment pollution due to high dispersion, and there is a mass excess comparing with spatter spray. Hot metal droplets were used to track the flow of jets. The major part of spatter being under solidification has the size of 200 micron by dispersion and can be picked up by modern exhaust devices. The time of droplets solidification reaching heat content magnitudes able to cause firing of cloth filters in dust-tripping devices was determined during the experiment. There was elicited 100 % capture performance of hot metal droplets being under solidification in a uniflow cyclone CP-2500 (ЦП-2500) using marking tracers from particulate matter determination method.