The U.S. Environmental Protection Agency (EPA) recently researched the volatile organic compounds (VOC) emissions of ABS filament that contained carbon nanofibre reinforcement.
VOC emissions arise from the melting of polymers in FLM/FFF/FDM processes and have been studied for its harmfulness in the last years. A 2017 study from Poland concluded that the melting of ABS, PLA, PET, and nylon filaments do not cause harm as long as adequate ventilation and precautions are taken care of.
In collaboration with the Consumer Products Safety Commission (CPSC), researchers from EPA have now explored and compared the VOC emissions of nanomaterials in 3D printing filaments on the example of ABS and carbon nanotube filaments (CNT). They used a Lulzbot TAZ 3D printer to quantify and characterize VOC emissions produced by the printing of carbon nanotube filaments (CNT) under a variety of different conditions such temperature, material heating duration and oxygen concentration. The team later used these factors in a System for Thermal Diagnostic Studies (STDS), to identify and compare combustion-related emissions. Compared to plain ABS, they found that CNT materials emitted two new VOC gasses with the potential to harm users when several kilograms of CNT material is printed, and the emissions are inhaled.
The print temperature showed the most significant effect on increasing VOC emissions, followed by the duration of heat applied to the material. The researchers call for further investigations to understand the potential impact on human health.