The 3D Printing Revolution-Environmental Health & Safety - Carnegie Mellon University

Wednesday, January 1, 2014

The 3D Printing Revolution

Enterprising people say, “If you build it, they’ll come!” But how do you build it, if it is small, intricate or has never been made before? Thanks to three-dimensional (3D) printing technology, the new motto is, “If you can draw it, you can build it!” 3D printers have been used to make all sorts of things, including a bionic ear, spare parts for just about anything, microscopic objects crafted with incredible precision, and even synthetic meat. 3D-printed clothes and accessories are “the new black.”

While desktop 3D printers have made rapid prototyping and small-scale manufacturing easier and more accessible, they are not without their hazards. In some 3D printing processes, thermoplastics are heated, nozzle-extruded and then deposited onto a surface to build the object. As a by-product of the process, nanoparticles (ultrafine particles less than 1/10,000 of a millimeter) are emitted. For a 3D printer that uses a low-temperature polylactic acid (PLA) feedstock, 20 billion particles per minute can be released, while a higher temperature acrylonitrile butadiene styrene (ABS) feedstock can release 200 billion.

Nanoparticles are of concern because they are very small, have a large surface area and can interact with the body’s systems, including the skin, lungs, nerves and the brain. Exposures to nanoparticles at high concentrations have been associated with adverse health effects, including total and cardio-respiratory mortality, strokes and asthma symptoms. While PLA feedstock is designed to be biocompatible, the thermal decomposition products of ABS feedstock have been shown to have toxic effects on lab rodents. Since most 3D printers do not have exhaust ventilation or filtration accessories, placement of the printer and selection of printing materials must both be carefully considered.  “Vive la Revolution,” but safely!

By: Michael J. Patrick, mjp@andrew.cmu.edu, 412-268-4931