Particle Emissions from Fused Deposition Modeling 3D Printers: Evaluation and Meta-Analysis (2018 NCSOT)
Citation:
Byrley, P., BJ George, W. Boyes, AND K. Rogers. Particle Emissions from Fused Deposition Modeling 3D Printers: Evaluation and Meta-Analysis (2018 NCSOT). 2018 NCSOT Annual Meeting, Research Triangle Park, NC, October 15, 2018.
Impact/Purpose:
Fused deposition modeling 3D printers, the most popular choice among home hobbyists, have been shown to release volatile organic chemicals (VOCs) and billions of airborne particles per minute, indicating the potential for consumer inhalation exposure and consequent health risks. Inhaled ultrafine particles have been linked to a variety of health effects including increased oxidative stress, inflammation, cardiovascular effects and cytotoxicity (Madl et al., 2009; Stefaniak et al., 2017). VOCs may contribute to the development of asthma, allergies, obstructive pulmonary disease and lung cancer with styrene classified as a known carcinogen (Gałęzowska et al., 2016; Lee et al., 2006). Publications on FDM 3D printer emissions; however, contain large heterogeneity of testing methods and analytical procedures making it difficult to reach overall conclusions from particle characteristics or particle number emission rates across the field.
Description:
PURPOSE & BACKGROUND Fused deposition modelling (FDM) 3D printers, the most popular choice among home hobbyists, have been shown to release volatile organic compounds (VOCs) and billions of airborne particles per minute, indicating the potential for consumer inhalation exposure and consequent health risks. Inhaled ultrafine particles have been linked to a variety of health effects including increased oxidative stress, inflammation, cardiovascular effects and cytotoxicity (Madl et al., 2009; Stefaniak et al., 2017). VOCs may contribute to the development of asthma, allergies, obstructive pulmonary disease and lung cancer (Gałęzowska et al., 2016; Lee et al., 2006). Publications on FDM 3D printer emissions; however, contain large heterogeneity of testing methods and analytical procedures making it difficult to reach overall conclusions from particle characteristics or particle number emission rates across the field. METHODOLOGY Data were collected over the printing time from 3D printer emission studies including particle count diameters (PCDs) (nm), particle number concentrations (PNCs) (particles/cm3), and particle number emission rates (PNERs) (particles/min). These data were sought to describe particle emissions across publications and to determine if two popular filament materials, acrylonitrile butadiene styrene (ABS) and poly-lactic acid (PLA) differed in the PCDs and PNCs of particles emitted. In addition, a mixed linear model was fitted for mean PNCs to explore the impact of nozzle temperature and filament material. Individual run data of PNC were also obtained from three authors and submitted to five PNER equations to determine if the calculation method affected reported PNERs (Azimi et al., 2016; Stefaniak et al., 2017; Zhang et al., 2017). RESULTS Despite heterogeneity in methods, the majority of particles released were ultrafine in size (i.e., <100 nm). The observed difference in means of 8.1 nm (48.5 nm for ABS and 40.4 nm for PLA respectively) indicates there is no substantive difference in particle inhalation exposure risk between ABS and PLA in terms of mean PCDs (Miller et al., 2016). Mean PNC emitted in 3D printing tests ranged over several orders of magnitude across publications with overall means of 300,980 particles/cm3 for ABS and 65,482 particles/cm3 for PLA. After adjusting for nozzle temperature, there was a substantial difference between filament types (235,498 particles/cm3). Finally, the PNER calculation method, especially regarding influxes and losses, varied widely across studies and directly impacted the PNERs reported. CONCLUSIONS Using both ABS and PLA may present a risk of inhalation of ultrafine particles and subsequent health risks. Although mean PNC data were available from only 7 of the 16 papers reviewed, results indicate that ABS use may lead to greater particle number exposure risk than PLA. To strengthen direct comparability of results going forward, it is recommended that standard emissions testing protocols be developed for FDM 3D printers and particle influxes and losses be more uniformly calculated.
