[Joel_Mckay]

There are active studies on chopped CF inhalation/contact hazards, and the SEM images in the above post prove how it occurs.

A lot of plastics contain wide assortments of additives to obtain mechanical properties. Outdoor ventilation is absolutely preferable to filtration or smell reduction filters that does practically nothing about carcinogens.

PLA is comparatively low emission, but a slow cooking PTFE tube in many hot-ends is not something people should be around. ymmv =3

[dgroshev]

There are different kinds of carbon fibres. It'd be great if it wasn't just Prusa disclosing which type they are using or offering studies on their impact, but in the meantime we can just use CF Prusament to be sure: https://www.reddit.com/r/3Dprinting/s/nQ5zUwnrWZ