Testing of particles and volatile organic compounds emitted during 3D printing using the FDM/FFF method

The Chemical Insights Research Institute at UL Research published a new study examining volatile organic compounds (VOCs) and particle emissions during the FDM/FFF 3D printing process. The answer to whether they are harmful to the health of users of this type of 3D printers turned out to be quite complicated…

In the research model, the worst possible scenario of exposure to harmful compounds was assumed to be a distance of approximately 1 meter from the operating 3D printer. In simulated non-industrial environments, scientists assumed that the only source of emissions was the 3D printer. Although 3D printing conditions in FDM/FFF technology play a key role in influencing emissions, the main factor is the material from which additive manufacturing is carried out. Different materials require different 3D printing settings. Filaments such as ABS, polyamide (nylon) and HIPS consistently had the highest particle emission rates, followed by metal-doped filaments and PLA. Formaldehyde was among the 5 most common VOCs in 7 of the 9 materials tested.

The metal-doped filaments showed larger particle sizes and higher mass emission factors, indicating a distinct emission behavior of these materials compared to pure polymer filaments. Total volatile organic compound (TVOC) emission rates varied between different materials, with ASA, PETG, ABS and some nylon filaments emerging as high emitters. On the other hand, metal-doped composite filaments showed lower TVOC emissions, probably due to the high metal alloy content. The five most frequently emitted VOCs were associated with the host polymer material, providing information on the specific chemicals released during the 3D printing process.

However, the study noted that correlating particulate matter and volatile organic compound emissions was difficult, as low or no correlation was generally observed. The article also notes that there is a large variation in emissions between different types of materials. Manufacturer-specific formulations and additives have emerged as potential contributors to high levels of certain VOC emissions, regardless of other 3D printing conditions.

While ABS and HIPS materials generated the highest concentrations, PLA, PETG, and PVA showed lower comparable median concentrations. The levels released were comparable to (but sometimes higher than) typical levels of ultrafine particles found in homes, offices and schools. The study suggests that personal exposure to emissions from FDM/FFF 3D printing is similar to indoor activities such as cooking on a gas stove.

Even though the study assumed an environment in which the 3D printer is the only source of emissions, in the real world, everything from our furnaces to air conditioners are a source of emissions in our homes and offices. These conditions may naturally result in spaces with higher than recommended particle concentrations. Airflow into and out of the room also plays a key role in all of this.

The most important conclusions from the article were as follows:

• avoid using high-emitting materials such as those containing styrene monomer
• avoid using the 3D printer in closed rooms or with limited ventilation.

Source: www.sciencedirect.com