Exactly how many nanoparticles were emitted and how toxic they were varied wildly, depending on printer temperature and filament type, but all the emissions levels were high. The lowest emissions, for instance, were still on the order of 20 billion particles per minute. On the high end, over ten times that number of were recorded. These are particles which can hang in the air and be easily breathable, potentially poisoning you while you sleep, as long as you're printing stuff in your bedroom in the middle of the night. And once inhaled, these tiny plastic particles could not only deposit themselves in your lungs, but might even work their way up into your brain by way of your olfactory nerve.