[WhiteDawn]

The results of this study actually presents that PLA fumes are more toxic than ABS fumes.

In practice though, the study shows PLA is safer because of significantly less fume creation with the lower printing temperature.

So relative risk for PLA is significantly lower than ABS, but it is incorrect to state that PLA is less toxic.

[postalrat]

You can smell the ABS fumes so they must be worse for you. The nose knows! /s

[calibas]

The human nose is an extremely sensitive chemical detector, and should not be dismissed. It's effective down to a fraction of parts per trillion for certain chemicals.

https://en.wikipedia.org/wiki/Odor_detection_threshold#Odor_...

[ClumsyPilot]

But for others, like carbon monoxide, it is useless and leaves you to die.

[LarryMullins]

You can't count on your nose to warn you, but when your nose does warn you it pays to heed that warning. If your nose is screaming at you to GTFO, listen to it.

You listen to your other senses, right? When you touch something hot, you listen to your sense of touch telling you that you're about to get burned. That doesn't mean your sense of touch can warn you of all hazards, but you certainly shouldn't ignore it when it does.

[Fomite]

That's my usual line when people talk about smell being indicative of how safe something is.

Farts smell. Carbon monoxide doesn't.