3D printer

3D printing is becoming increasingly popular and is being used in a wide range of applications. The applications of 3D printers extend from the private sector to teaching, research and development, and industrial production.

Among the 3D printing processes, fused deposition modeling (FDM) is one of the most widely used techniques. The filaments often consist of thermoplastics such as polylactic acids (PLA) and acrylonitrile-butadiene-styrene copolymers (ABS). These plastics are melted and applied to a work surface by an extruder under pressure. The temperatures during the melting process are usually between 180 °C and 270 °C. Ultrafine particles (UFPs) and volatile organic compounds (VOCs) can be released during this process.

As a result, the operation of a 3D printer can also affect indoor air quality. Under certain circumstances, the emissions can be harmful to health.

Emissions of SVOC und particles

Due to the heating during the melting process, the thermoplastics used as filaments can release semi-volatile organic compounds (SVOCs) into the air. These are, for example, plasticizers, flame retardants and antioxidants that have been added to the filament to achieve certain desired properties (so-called additives). Particles are also released during the printing process. These are primarily ultrafine particles. Factors that influence the formation and emission rate of particles include the type of plastic used (thermoplastic) and the printing temperatures. In general, higher emission rates are observed when using ABS than when using PLA. In addition, higher printing temperatures usually also lead to higher emission rates. To avoid emissions of particles and SVOCs, it is therefore recommended to choose the lowest possible printing temperature.

Emissionen of VOCs

A large number of VOCs are also released during the 3D printing process. These are mainly decomposition products, so the substances emitted depend on the type of plastic used. For example, styrene is a characteristic emission of ABS. PLA, on the other hand, emits lactide, a cyclic ester of lactic acid. Polyamide releases caprolactam. According to the latest studies, the plastics PLA and PETG (polyethylene terephthalate modified with glycol; PET) have the lowest emission potential. Higher VOC concentrations are released by ABS and polyamide (in that order).

If adhesives are also used, these can also contribute to emissions, although usually to a lesser extent. The emission of organocyclosiloxanes during the warm-up phase of a 3D printer indicates that greases and lubricants used in the mechanics of the printer can also emit VOCs.

Gu, J. et al. (2019) Characterization of particulate and gaseous pollutants emitted during operation of a desktop 3D printer. Environment International 123: p. 476-485.

Stabile, L. et al. (2017) Airborne particle emission of a commercial 3D printer: the effect of filament material and printing temperature. Indoor Air 27(2): p. 398-408.

Azimi, P. et al. (2016) Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments. Environmental Science & Technology 50(3): p. 1260-1268.

Gümperlein, I. et al. (2018) Acute health effects of desktop 3D printing (fused deposition modeling) using acrylonitrile butadiene styrene and polylactic acid materials: An experimental exposure study in human volunteers. Indoor Air 28(4): p. 611-623.