AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Aerosol and Gaseous Pollutants Emission from a Desktop Laser Cutter and Engraver
JUN WANG, Kevin O'Neill, University of Oklahoma
Abstract Number: 752 Working Group: Aerosol Exposure
Abstract The emission of laser generated airborne contaminants (particles in respirable fraction mass and sub-532 nm fraction numbers, VOCs, and CO) were examined in this study. The experimental matrix comprised of four different materials (cardboard, wood, plastic, and glass) and three different currents. The efficiency of exhaust ventilation was evaluated. Particle emission in the respirable fraction and the ultrafine fraction is particularly a concern for nanotoxicity and potential user exposure. A large percentage of the experiment resulted an overexposure to respirable particulate mass comparing to OSHA PEL of 5 mg/m3 despite the short period of sampling time. Cardboard consistently produced highest respirable particulate mass (0.37 mg), high emission rate of particles smaller than 532 nm (2.37 × 1010 #/min) with the smallest geometric mean diameter (82.1 nm without ventilation). This hints that cutting cardboard should be exercised cautiously. On the contrary, glass was very robust and resist to thermal cut and less amount of respirable particulate mass (0.12 mg, in some cases below LOD), with a close to the background level of particle size distribution in the sub-532 nm range. Wood and plastic were in between cardboard (high) and glass (low) in terms of respirable and ultrafine particle production. Materials with relative higher carbon content were able to generate more VOCs and CO such as wood and cardboard. Plastic cutting emitted more VOCs while CO was absent. Glass was very inert to gas emission and no VOC or CO was observed when engraving glass. Ventilation control was able to mitigate all aspects of emission to certain scales. It can effectively reduce respirable particulates mass by averaging 61%, and decrease ultrafine particle emission rate by magnitudes. Ventilation was able to completely remove all gaseous contaminants generated. Therefore, it is highly recommended to implement ventilation while conducting laser cutting/engraving.