It's worth bearing in mind that those bar charts on the Nevermore repo are showing the ratio of VOCs rather than the quantity, so make particularly nasty materials like ABS appear comparable to much safer ones like PLA. It's not going to do you any good if you melt several kilos of PLA in a pan then take the lid off and huff the fumes, but running a single 3D printer with PLA in a large room is going to be pretty safe. The main VOCs emitted by PLA aren't that harmful - some like acetone and acetaldehyde are produced by the human body and found in food (athough turning alcohol to acetaldehyde is what causes hangovers), methyl methacrylate is used to glue in hip replacements, and isobutanol is often a fermentation byproduct that ends up in alcoholic drinks. That doesn't mean that PLA fumes are completely harmless, but means that it's not worth worrying about the level of harm as running a printer in a room with the door open for a whole day is probably somewhere around the level of harm as eating cooked food or having a small beer.