Physicochemical characterization of oily particles emitted from different machining processes

Oily particles emitted from different machining processes can get deep into the respiratory system and have adverse effects on human health. But the toxic associated physicochemical characterization of the oily particles is still not fully understood. This study combined with an improved strategy and off-line analysis to obtain the characteristics of the oily particles emitted from different machining processes. A factory was selected for our study where the grinding, wet-lathing, dry-lathing, milling and intercritical hardening processes intensively lay together with operational workers. The results showed that the particle concentration of the various machining processes ranged from 2.1×105 to 2.8×105 p/cm3 with a large proportion of fine and ultrafine oily particles. Most of these particles agglomerated into flakes having small spheres attached to them, but a special rod shape particles were observed in the milling processes. The oily particles contained Fe, Si, Na, Mg and Al, and the metallic elements had a comparable mass in both fine and coarse particles. In addition, ultrafine particles had higher oil portion than the larger particles. The results could be employed for exposure assessment and were helpful for industrial hygienists to develop better strategies for the removal of the particles from workplaces.