As someone who does R&D testing on plastics that are used in medical devices, I have some insight. Of course the type of plastic matters, but all plastics use carcinogenic chemicals during the manufacturing/extrusion process.

To make most plastic, a polymer resin is mixed with additives such as solvents, plasticizers, and stabilizers at high temperatures. Ideally, you want the additives to evaporate out during production so that you're left with just the newly formed plastic.

But some of these additives get trapped in tiny air pockets between polymer chains. When they're reheated, the polymer chains relax and release the volatile, carcinogenic additives into the air.

This is likely where the toxicity is coming from, not the polymer chain itself. So regardless of the type of plastic used, reheating the polymer during 3D printing will release some volatile additives.

tl;dr maybe don’t sleep where you print

Does this mean that 3D printing causes cancer? No, not by a long shot. But, it’s clear that under lab conditions, exposure to either PLA or ABS particulates seems to be related to some of the cell changes associated with carcinogenesis.

There was that video from a few months ago from... Prints with layers I think? That looked at the actual particulate and volatile counts and found that PLA actually gave off very little? Other plastics were much worse.

So remember that the particle counts matter as much as the danger of the particles.

(Disclaimer, that was a video, not a peer reviewed scientific paper)

I misread the headline. I thought 3D printers were evolving into crabs.

Printing using PLA in the basement, with a filter, not being in the room until the print is actually done. I feel pretty safe.

What does this all mean to the home gamer?

Oooook…..

Plot twist!

This took an interesting turn!

I wonder when the government will control water washable print resins.