I use ABS and PLA. PLA seems to gum up the outer surface of the nozzle a bunch more and I always have a little trouble getting ABS restarted after using PLA. In a lot of ways, I feel that ABS is easier than PLA – it definitely looks nicer. I set up a simple vented hood and I don’t notice any smell from ABS.
I would be careful about exposure to fumes, even if you can’t smell them. I had an allergic reaction to HIPS fumes (small numerous water blisters on the sides of my fingers, which itch, pop, produce scaly skin that itches for a month till my skin turns over – fumes that hit my face when looking at a printing object, caused a sunburn like reaction on my face). About 5-6 years ago, I did a ton of work on a fiberglass boat and was exposed to a lot of epoxy and polyester resin and became sensitized to those things. Even the smallest amount on my skin now causes that hand reaction I mentioned (the sunburn like reaction is new). Now, whether repeated exposure to HIPS would cause that sensitization to occur, or whether you need to bathe in other resins first like I did – I don’t know. The thing with some of these chemicals though is that at first they don’t have any effect on you, but once you hit the sensitization threshold, using them becomes very complicated or even inadvisable.
Long way of saying, even if you don’t smell anything, you aren’t going to go wrong by rigging up some ventilation and eliminating the chance you’ll develop a sensitivity to the fumes.