"The toxicity tests showed that PLA particles were more toxic than the ABS particles on a per-particle comparison, but because the printers emitted so much more of the ABS"
But I would be very scientifically comfortable that ANY plastic brought at or above its glass transition state is going to outgas toxic materials. And that includes PLA, ABS, HIPS, polycarbonate, PETG, PET, ASA, and more. And printing is usually quite a bit above tg. Higher temp = more nastiness.
That's why my 3d printers are in my workshop, separated from our house. And they are also enclosed printers, so I'm less worried of particulate exposure. But again, anybody starting off early in 3d printing knew this was a definite threat and a concern.
Anybody talking about the toxicity of lactic acid on the context of perfectly fine breathable air is bull of bullshit.
And yes, we have known since forever that it is highly toxic. It's also common on your organism, on much higher concentrations than you will get from your printer.
Anyway, the common advice applies. If you get a 3D printer, use it on ventilated spaces, and if you will print with anything that isn't PLA, make sure it is well ventilated and doesn't ventilate into anybody. What really surprised me was this:
> these tests indicate that exposure to these filament particles could over time be as toxic as the air in an urban environment
I expected it to be much worse. Printing ABS does surely not smell like an urban environment. I guess a 3D printer generates much fewer silent poisons than a city.
"The toxicity tests showed that PLA particles were more toxic than the ABS particles on a per-particle comparison, but because the printers emitted so much more of the ABS"
so, not just ABS