Lung cell toxicological effects of 3D printer aerosolized filament byproducts

As 3D printing has become more compact and affordable, the use of the technology has become more prevalent across household, classroom, and small business settings. The emissions of fused filament fabrication (FFF) 3D printers consist of volatile organic compounds (VOCs) and aerosolized particulate matter (PM) dependent upon the filament in use. This study investigates the hazards posed by these emissions through aerosol characterization and cell exposure. Seventeen filaments were obtained from five manufacturers, consisting of fourteen plastic filaments (polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), or polycarbonate (PC) polymers) and three filaments with metal filler (copper, bronze, and steel). For 1-h trials, BEAS-2B human bronchial epithelial cells were directly exposed to aerosolized 3D printer emissions at the air-liquid interface (ALI). Particle characterization showed ABS filaments produced more PM and VOC emissions with particles in the ultrafine size range. ABS filaments also elicited a greater biological response, with significant shifts in mitochondrial activity compared to the PLA filaments. Significant changes in amounts of glutathione (GSH) were observed after ABS and PLA emission exposure. Exposure to emissions from the steel filament resulted in the lowest average amount of glutathione, though insignificant, and a significantly lower mitochondrial activity, revealing a unique cause for concern among filaments tested. 3D printer emissions and subsequent cell responses appear filament-dependent, and users should mitigate personal exposure to aerosols.