As an emerging technology, three-dimensional (3D) printing has gained much attention as a rapid prototyping and small-scale manufacturing technology around the world. In the changing scenario of library inclusion, Makerspaces are becoming a part of most public and academic libraries, and 3D printing is one of the technologies included in Makerspaces. Owing to the ease of availability and cost effectiveness, most libraries use fused-deposition-modeling-based 3D printers compatible with plastic printing materials, such as polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). During the printing, PLA and ABS emit ultrafine particles (UFPs) and volatile organic compounds (VOCs) that may deteriorate the indoor air quality. In this article, first, we have discussed the background of 3D printing, the most common technologies used for 3D printing and printing materials, its applications in chemical education and sciences, as well as 3D printing health and safety concerns. Second, we measured and analyzed the number of UFPs (0.02-1.0 µm) in the 3D printing lab in a library and found that the number of particles/cubic centimeter significantly increased during the printing procedure (36-60 times) and does not return to baseline even 24 h after shutting down the printers. We also provide some recommendations that should be considered when hosting a 3D printing lab in libraries.