Many people find the smell of plastic from a 3D printer to be particularly noxious. Plus, some studies have shown that plastic fumes are toxic, especially to small children or people who have asthma. But filtering 3D printers is tricky: evacuate too much air and there won't be enough heat for a quality print; evacuate too little air and there won't be much odor reduction.
If you have access to a window, the safest thing to do is to vent the fumes to the outside using this vent adapter. (If you use this vent, remember to tape up the flap!) But if that isn't feasible, then reduce the complaints about smells with this active carbon filter kit. It's tuned to reduce the odors associated with 3D printing while retaining enough heat for a good print. The activated charcoal filter has an especially high carbon content (300g/sq ft) and is proven to remove odors and volatile organic compounds from air down to 3 microns in size. We have no idea if that decreases the health risks since there aren't any scientific studies on the subject, but reducing complaints about the smell sure makes it easier to run a 3D printer in the house.
The carbon air filter is designed to work with any 3D printer enclosure by drilling the right-sized holes to mount the filter. Of course, all 3DUPfitters enclosures come with the mount point pre-drilled and ready to go. The 80mm filter is designed for a low CFM rate that won't create a noticeable airflow inside the enclosure that can warp prints while still filtering the air. The 120mm filter on the other hand is designed for resin printers and very large enclosures which are primarily concerned with getting the best air quality without venting to the outside.
Note the price. Industrial level filtration systems go for north of $800. If you want the best, then this isn't for you. The picky people who've complained about smells around here say it's no longer an issue. The smell went from permeating the entire upstairs to being noticeable only when sticking our noses right next to the printer.
Everyone has a different sensitivity to odor, so give it a try for 10 days, and if it doesn't meet your expectations just return it for a refund. (You pay return shipping.)
Every 3DUPFitters enclosure comes pre-drilled with the vent and mounting holes, but this kit adds:
5V USB A
Resin Printers, Large Enclosures
The 80mm fan can either be plugged into a USB power supply (not included) or the wires stripped and connected directly into some models of 3D printers. Note that USB wire is only around 12" or so, and won't reach a wall socket. We plug ours into a Raspberry Pi running Octoprint, but you'll have to purchase some other form of USB power supply if you don't have one already.