3d printers

3D printers can be toxic to humans

Several new studies have revealed that 3D printers emit toxic particles that can be harmful to humans.

The studies, presented at 2020 Virtual annual meeting of the Society for Risk Analysis on December 15, showed that particles released during the printing process can affect indoor air quality and public health.

For the uninitiated, 3D printers typically work by melting filaments of plastic or other base materials such as nanoparticles, metals, thermoplastics, etc., and then stacking the melted materials layer upon layer to form an object. When plastic or other base materials are heated to melt, they release volatile compounds into the air near the printer and the object.

Chemical by-products and particles that are released into the environment during the printing process can build up the longer the process takes and some are small enough to seep into the lungs and cause damage.

The studies presented today at the meeting looked at various types of emissions and the magnitude of the risk.

For example, two of the Environmental Protection Agency (EPA) studies analyzed emissions from a 3D printer filament extruder – a device used to create 3D printer filaments – and then used a simulation model to see how many particles were produced, as well as where they were deposited when using a 3D printer in different age groups.

The studies found that the filament extruder released amounts of small particles and vapors similar to those found in other 3D printer studies, and the simulation model predicted higher particle mass deposition per surface in the lungs for children nine and under. But more research is needed to determine what the inhaled dose would be.

Another of the featured studies, led by Yong Qian of the National Institute for Occupational Safety and Health, investigated the potential toxicity of acrylonitrile butadiene styrene (ABS) emissions generated during 3D printing by examining cells human lungs and rats exposed by inhalation. It found that the emitted particles cause moderate toxicity in human lung cells and minimal toxicity in rats.

It should also be noted that while much of the research presented today is still in its infancy, it adds to the growing evidence the potential toxicity of 3D printers.

For instance, research published last year found that ABS and polylactic acid (PLA) particles negatively impact cell viability, with the latter eliciting a more toxic response.

“Toxicity tests showed PLA particles to be more toxic than ABS particles on a per-particle comparison, but since the printers emitted a lot more ABS, it was the ABS emissions that ended up being more concerning,” Rodney said. Weber, a professor at Georgia Tech’s School of Earth & Atmospheric Sciences, who led the research. “Taken together, these tests indicate that exposure to these filament particles could over time be as toxic as the air in an urban environment polluted by vehicles or other emissions.”

The study also found that the higher the temperature required to melt the filament, the more emissions were produced and the ABS particles emitted from the 3D printers had different chemical characteristics than the ABS filament.

“When filament companies make a certain type of filament, they may add small mass percentages of other compounds to achieve certain characteristics, but they generally don’t disclose what those additives are,” Weber said. “Because these additives appear to affect the amount of emissions for ABS, and there can be great variability in the type and amount of additives added to ABS, a consumer may purchase certain ABS filament , and it could produce a lot more emissions than just one from another provider.”

This is important, especially as 3D printers become more common in homes, schools, and other places where people spend a lot of time.

“To date, there is little awareness among the general public of possible exposures to emissions from 3D printers,” Peter Byrley, one of the lead authors of the EPA studies, said in a statement. “A potential societal benefit of this research is to raise public awareness of 3D printer emissions and the possibly higher sensitivity of children.”

And 3D printing might not just be harmful to humans, another study led by Duke University’s Joana Marie Sipe found that byproducts of printer-made plastics can also be harmful to humans. environment.

For the study, Sipe developed a machine that can measure how much a plastic product, like a water bottle, can break down through friction and sanding during use and in the environment. The plastic particles were then fed to the fish to see what effects the plastic nanoparticles had on their organs.

What she discovered is that when plastics break down, the embedded nanomaterials are exposed to the environment. The researchers were able to predict the percentage of nanoparticles that released from the plastic when eaten by fish, providing a Matrix Release Factor (MRF) that could be used to find out how much plastic and nanoparticles are released when someone eats them. one chews a product or when it breaks down in the ocean.

“This research can help establish regulations on the amount of nanomaterial fillers that can be added to particular consumer products, based on their MRF value,” Sipe said in a statement. “The data can help determine how much plastic and/or nano-filled products are releasing contaminants into the environment or the human body.”

So while 3D printing is making many products more readily available and cheaper, as we have seen with the manufacture of face shields, respirators and other Covid-19 personal protective equipment, it is important to consider the potential risks. And as 3D printing technologies become more mainstream, regulators, manufacturers, and users may need to focus their attention on better managing these risks.

For instance, some measures that can be taken by 3D printer operators to reduce their impact on air quality include:

  • Use 3D printers only in well-ventilated areas
  • Setting the nozzle temperature at the lower end of the suggested temperature range for filament materials
  • Stay away from running machinery
  • Use machines and filaments that have been tested and verified to have low emissions.