Evaluation of emissions and exposures at workplaces using desktop 3-dimensional printers

Abstract

There is a paucity of data on additive manufacturing process emissions and personal exposures in real-world workplaces. Hence, we evaluated atmospheres in four workplaces utilizing desktop “3-dimensional” (3-d) printers [fusedfilamentfabrication(FFF) and sheer]forproduction, prototyping, orresearch.Airborne particle diameter and number concentration andtotal volatile organic compound concentrationswere measured using real-time instruments.Airborne particles and volatile organic compoundswere collected using time-integrated sampling techniques for off-line analysis. Personal exposures for metals and volatile organic compounds were measured in the breathing zone of operators. All 3-d printers that were monitored released ultrafine and fine particles and organic vapors into workplace air. Particle number-based emission rates (#/min) ranged from 9.4 109 to4.4 1011 (n = 9 samples)forFFF3-dprinters andfrom1.9 to3.8 109 (n = 2 samples)for a sheer 3-d printer. The large variability in emission rate values reflected variability from the printers as well as differences in printer design, operating conditions, and feedstock materials among printers. A custom-built ventilated enclosure evaluated at one facility was capable of reducing particle number and total organic chemical concentrations by 99.7% and 53.2%, respectively. Carbonyl compounds were detected in room air; however, none were specifically attributed to the 3-d printing process.Personal exposure to metals (aluminum, iron) and 12 different organic chemicals were all below applicable NIOSH Recommended Exposure Limit values, butresults arenotreflectiveof allpossible exposure scenarios.More researchisneeded tounderstand 3- d printer emissions, exposures, and efficacy of engineering controls in occupational settings.