Evaluation of Particle and Nanoparticle Emissions in Fiber and CO2 Laser Cutting Processes

Laser cutting processes entail the cutting of metal sheets by the emission of a laser source that melts the material along defined paths, potentially generating incidental metal nanoparticles (IMNPs). These particles have been associated with genotoxicity, oxidative stress, and pro-inflammatory responses. However, quantitative data on IMNP emissions remain limited. This study assessed IMNP emissions from CO2 and fiber laser cutting through two monitoring days at a high-precision metalworking facility in Italy. The first day dealt with environmental monitoring, while the second included both personal and environmental monitoring. Personal sampling consistently indicated elevated particle number concentrations and lung-deposited surface area, with average values reaching up to five times the background level (161,960 n/cm3) and peak concentrations as high as 2,781,962 particles/cm3. Environmental concentrations increased significantly only during CO2 stainless steel cutting (95,670 n/cm3). Depending on the process, 73–89% of the emitted particles were <300 nm, with substantial enrichment in the nanoparticle fraction. Emission profiles varied by laser source, metal, and sheet thickness, with the highest concentrations recorded during CO2-laser cutting of stainless steel. These findings provide preliminary evidence of occupational exposure to IMNPs during laser cutting and highlight the need for systematic exposure assessments to quantify the potential occupational health risk.