Anyone who uses a 3-D printer at work or home knows the tell-tale scent of the machine at work, a slightly burnt chemical odor that fades over time. If you're like me, you've long wondered whether you should worry about it. Now, a team of scientists from have published a study proving that yes—there are hazards in 3-D printing in enclosed spaces, especially with certain materials. But there are ways to mitigate it, so don't panic.
The study, which was published in Environmental Science & Technology, tested five major brands of 3-D printers, looking for two things: one, the level of "ultrafine" particles they emit, which can be dangerous to inhale. Second, the level of dangerous volatile organic compounds emitted from heating plastic, also linked to health hazards in animals. It's a serious issue, the authors say, because most commercial 3-D printers or printing materials haven't been studied. "Only a very limited number of makes and models of printers have been tested to date, and even fewer filament materials have been characterized for gas and/or particle emissions," they write.
According to co-author Brent Stephens, who works at the Illinois Institute of Technology, the impetus for the study came from very close to home. "We were prompted to study this back in 2013 when a student in my class was curious about odors emanating from 3-D printers operating in his office," he told Co.Design. "So we first conducted a pilot study of ultrafine particle emissions from just one type of printer with only two types of filaments, and then once we realized that those could be quite high, we figured that they were also emitting gas-phase pollutants as well."
The methodology was simple. Each of the five printers tested (FlashForge Creator, Dremel 3D Idea Builder, XYZprinting da Vinci 1.0, MakerBot Replicator 2X, and LulzBot Mini) spent between two and four hours printing out a sample object that looked like this. A particle counter tallied the number of ultrafine particles each test was spewing into the airtight room, while also sampling air quality for VOCs following the EPA's own standards. They also tested more than a dozen materials, ranging from ABS and PLA to wood and clear polycarbonate.
What they found was that the level of harmful particles and fumes depended mostly on the filament material, not the maker of the printer. For example, ABS emitted styrene, a type of chemical that's toxic and carcinogenic. Other materials based on nylon emitted caprolactam, a chemical linked to a laundry list of health problems. Meanwhile, the PLA filament emitted lactide, which is actually pretty benign. All told, the levels of ultrafine particles reached concentrations 10 times as high as a normal office or lab.
So, what does this mean for you? First, make sure your fab lab is well-ventilated. Second, try to limit your exposure when you're using ABS and nylon-based materials. But the authors end by pointing out that the onus is on the industry to develop new, non-toxic printing materials for consumers—and if that proves impossible, to change the design of the printers themselves to be air-tight. Chicago Tribune points out that there are a few startups at work on this very problem already. "Until then," the paper's authors write, "we continue to suggest that caution should be used when operating many printer and filament combinations in enclosed or poorly ventilated spaces or without the aid of gas and particle filtration systems."
Hopefully, the inherently unpleasant experience of huffing hot plastic fumes means that you already limit your time near your 3-D printer. But if not, now's the time to start. We're only just beginning to understand how this rapidly evolving technology affects us.