Warning: Reading this post may increase your desire to browse WebMD, a database known to the State of California to contain cancer.
The Smell of FFFear
It’s no secret that overheated plastics smell a bit…odd. What may surprise the average person is how complex and dangerous that smell can be. Researchers from the Underwriter’s Laboratories (UL) and the Georgia Institute of Technology noticed that a lot of people like to buy plastic on spools and melt it for amusement, or as practitioners prefer to call it, “3D Printing.” The most common and affordable type is Fused Filament Fabrication (FFF), and the TR Forums include a number of people interested in the process.
In basic FFF printing, a 3D computer model is created by the user and then digitally sliced by the software into a stack of 2D layers. A 3-axis printer then feeds a spool of thermoplastic material into a high-temperature printing nozzle that recreates each pattern layer in succession. Eventually, 3D objects of either great use or great disaster are constructed, depending on how well the the plastic, the printer, and the source model agreed with each other’s needs. The applications are nearly endless. If YouTube hits are a decent barometer, the Warhammer community alone has been advanced at least 50 years. (Just 37,931 more to finally get there.) Want to combine old and new? Perhaps you might be interested in 3D printing at HO scale?
Now for the catch: heated plastics can release Volatile Organic Compounds (VOCs) and tiny particulates into the air. According to the August research paper, which was picked up again this week by TechRadar, at least 216 unique compounds have now been identified, with the lowest average concentrations generated by typical PVA blends and the highest by nylon. While this is not the first study on 3D printing emissions, the authors claim to have identified a far greater range of compounds than previously reported.
Benzene for Breakfast
The output of this robotic vaping is classified variously as odorants, irritants, and carcinogens. As long as a compound only hits the first two, i.e. “it smells” or “it itches and my eyes are watering,” the effects may only be nuisance. But that latter list includes chemicals with suffixes like “-ene” and “-aldehyde,” which will cause your local organic chemists to sit up in unison and adjust their spectacles (or beards). Meaning, your monofilament kit’s Proposition 65 label finally got one right.
At casual glance, a slowly devolving spool of glorified fishline may not look like a hazard to anything but your hobby budget. The problem is that 3D printing, especially on lower-cost kits that a home hobbyist might run, is time-intensive and often performed in enclosed spaces like offices, basements, or other small workrooms. Residential settings also tend not to have continuous-flow HVAC systems. After running a 3D printer all night behind a closed door, things add up — both for your wallet, and for airborne VOCs.
Time To Meet Your Biggest Fan
Purportedly, the best solution is more ventilation. To recap Paracelsus, “All things are poison and nothing is without poison; only the dose makes a thing not a poison.” So, reduce the risk by lowering the dose: treat your 3D printing sessions as you would treat a round of painting or woodworking, and get the fresh air moving. That is, unless you’re one of those odd birds who thinks that mind-altering fumes are a side benefit of your hobbies, in which case (a) we can’t help you further and (b) the WebMD diagnosis was, in your case, likely correct.
The study authors worked with 25 filaments of various types, and print durations in the 3-5 hour range, producing long lists of emissions data and equally long words. If you want more details on their methods and results, or just a lot of really neat charts and plots like we used to give you around here, check out the study paper. It can be viewed online or as a PDF download.