The September 10, 2019, issue of the U.S. Environmental Protection Agency’s (EPA) Science Matters newsletter includes an article entitled “Keeping up with 3D Printing:  EPA Researchers Build on New Plastic Emissions Study.”  According to the article, EPA scientists, through an agreement with the Consumer Products Safety Commission (CPSC), are investigating whether increased use of 3D printers can lead to unintended adverse impacts to human health.  EPA states that while there have been studies on the effects of volatile organic compounds (VOC) from 3D printing, none have considered how the emissions change when certain additives are introduced to the 3D printing filament.  The scientists studied a commonly available filament that is sold both with and without carbon nanotube inclusions to determine whether VOC emissions changed between the two types of product.  The scientists quantified and characterized VOC emissions from carbon nanotube filaments under a variety of conditions intended to simulate the different heating, melting, and forming of plastics that can occur during 3D printing.  The scientists concluded that:  (1) the filaments with carbon nanotubes emitted two new VOC gases that could potentially pose an inhalation hazard to users printing several kilograms of material; (2) increased print temperature had the most significant effect on increasing VOC emissions, followed by increased length of time heating the material; and (3) carbon nanotube filament may “trap” certain VOC gases in particulates of the printed plastic.  The article notes that EPA’s research to understand exposure to and the health effects of nanomaterials is conducted as part of the interagency National Nanotechnology Initiative (NNI).  Other NNI members conducting research on 3D printer nanomaterials include CPSC and the National Institute of Standards and Technology (NIST).