RMIT scientists investigate health hazards of 3D printing

Additive manufacturing, commonly referred to as 3D (three-dimensional) printing, refers to technologies capable of making 3D objects from raw materials such as polymers and metals based on computer 3D parametric models.

Instead of cutting or ablating material, 3D printers build objects by depositing material, layer by layer, hence they are referred to as additive manufacturing technologies.

3D printers are more popular than ever, with the technology being used to create everything from running shoes to supercars. The popularity of 3D printers is at an all-time high, with the market predicted to be worth over $21 billion in worldwide revenue by 2020.

Given the increasingly widespread use, RMIT researchers believe that greater attention should be paid to how potentially harmful common 3D printing materials may be.

A team led by Associate Professor Donald Wlodkowic has conducted a pilot study that discovered that parts made using certain 3D printing processes could be unsafe, as they appear to leach large quantities of toxic substances when in contact with water.

"Critical biocompatibility issues and potential hazard risk implications of widespread usage of 3D printed polymers have so far received only marginal attention", Wlodkowic said.

"We used both cell-based assays as well as whole-organism biotests to screen for risks of exposure to 3D printed parts as well as potential leachates of toxic molecules from 3D printed plastics.

"This process highlighted the toxicity of 3D printed polymer and allowed us to establish a predictive analytical workflow to rapidly determine the toxicology of a burgeoning number of polymers used in 3D printing.

"We have already found one very toxic substance that has recently been reported as leaching from plastic ampoules used for intravenous injections."

Currently, the precise material composition used to create 3D printed parts is not always disclosed by manufacturers, so it's difficult to accurately assess the long-term risks they pose.

It is anticipated that the study will enable a fundamental characterization of health and environmental risks posed by exposure to new 3D printed materials.

Health risks are currently unknown but allergies through skin contacts are possible, as skin is the most common route of exposure to photopolymers during handling of parts and 3D printing materials. Moreover, there are significant environmental ramifications as 3D printed plastic pollution is on a horizon.

"We live in an era of explosive growth of 3D printing industry. It is estimated that by the end of 2019 we will achieve more than 5.6 million shipments of 3D printing technologies globally," he said.

"This will translate to large volumes of 3D printed waste materials that need to be safely disposed."

Wlodkowic said that at present there are no regulatory systems in place to evaluate consequences of increased human exposure to 3D printed parts, their environmental impact on food chains and most importantly, strategies for the safe collection, treatment and disposal of parts and waste generated during additive manufacturing processes.

"Based on our pilot studies, we garnered evidence that many of the polymerized resins used are unsafe. This data warrants development of a larger study to perform comprehensive exploration at genomic, cellular, and organismal levels.

"The impact of our research is significant. 3D printing is being rapidly adopted in multiple Australian industries. In light of this manufacturing revolution, the Australian population's exposure to a variety of new polymers will be increasing exponentially.

"The results carry significant consequences for researchers within healthcare, bioengineering and biomedical devices communities, in which 3D printing and more generally rapid prototyping technologies have provided an opportunity to generate physical parts or devices in a short period of time, directly from computer-based designs.

"Similarly researchers within the broader field of life sciences have now recognised the benefits of these technologies, and our findings provide a route towards assessment of a plethora of devices fabricated using additive manufacturing to ensure biocompatibility."

In light of that, the researchers from Wlodkowic’s team believe that their findings highlight the need for better regulation of the 3D printing industry, particularly regulations related to the materials used to create 3D printed parts.

The researchers have recently published their pilot findings in the Lab-on-a-Chip and Biomicrofluidics journals as well as proceeding of SPIE - the international society for optics and photonics.

Story: Petra van Nieuwenhoven