I have just bought my own 3D printer. However, I am now reading that there may be some safety risks to 3D printing. I will be taking some precautions, such as buying an enclosed 3D printer (the FlashForge Adventurer 3), using PLA instead of ABS, and putting my 3D printer in my garage. However, I am still concerned about the possible risks. What are some other good safety tips and best practices when 3D printing? Am I doing enough, or should I do more? What have other users of 3D printers done to mitigate potential safety issues? Please let me know.
Check where the moving cables (especially for the heaters) are bending. The bending radiuses should be as wide as possible and connections or soldering points should never see any direct force from movement. Add a strain reliev if there are any such connenctions to prevent them from failing over time and possibly melting down.
There are several ways to be injured with a 3D printer. The biggest threats come from the printer running under normal conditions. The uncommon, exceptional, and difficult to quantify threats come from fire and fumes.
For fire, consider the 3D printer to be like any other 400W heating appliance in your house, with the advantage compared to, say, a television in that you can inspect most of the failure points.
Check the feed points where the power connects to the power supply, main board, and the power lines to the bed heater and hot-end heater cartridge. After a few hours of printing, these should still not be hot.
There is always the possibility of a thermistor failure and thermal run-away. Most good control firmware should detect this possibility and fail with an error. If you are using custom firmware, you might want to check that this is included.
For fumes, the evidence is real that fumes are produced. It is less clear the nature and dosage of their effects. If the fumes bother you, don't breath them. If you are concerned, consider an enclosure with an activated carbon filter.
For the more immediate threats, you need to always take care when working with the printer. The hot end can burn you quickly. The heated bed can burn you more slowly. Gears, belts, and moving parts cause pinching hazards, and blood blisters can be raised easily.
Glass beds may have sharp edges, and can break to create thousands of sharp edges.
In conclusion, remember that stamped sheet metal parts, present on some printers, can bear burrs and sharp edges, inviting you to leave bloody finger prints.
A 3D printer, like many things, is dangerous in many ways. I've experienced the common threats, and have avoided the less common ones.
Be careful, but in my view a personal 3D printer is by far safer than any metalworking machine. I have been more injured by a drill press, and welding fumes are more noxious then filament out-gassing.
Technically, you should never leave your printer running unattended. Printer fires are rare, but it can happen, especially with cheap printers with poor quality control. Personally, I would just make sure that there is a fire alarm near by, so you'd be alerted if there was a fire.
Also, the fumes concern is valid in the sense that you don't want to sleep in the same room as your 3D printer. The following article points out that if you are spending time in the same room without proper ventilation you'd benefit from potentially using an enclosure with a HEPA filter. Also, the article points out that using PLA may be a safer choice than other materials such as ABS or Polycarbonate when it comes to harmful particles: https://3dinsider.com/3d-printer-fumes/
Assuming you are using PLA filament, it is plant-based and very safe. The reason some 3D printers have enclosures is becasue it helps keep some materials warm, its not for safety and especially not for fumes. You could run the thing in your bedroom 24/7 and I guarantee you would be plenty safe.