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.

What does this all mean to the home gamer?

Oooook……

Plot twist!

This took an interesting turn!

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

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.

Wow who would have thunk the chemicals getting dumped into the environment by the fucking oil industries could be dangerouse. There are a million 3d printing materials u can use and have decent extraction and ur fine. Guy u need to be scared 3d printers might give the consumer too much power, cant have foss technology winning out.