This article discusses a problem….and solutions.
The problem is air purity. A recent study identifies a startling variety of potentially toxic aerosols produced by 3D printer emissions, and the conditions under which they’re produced. Our health is certainly not something to be taken lightly. At i3D, we believe it’s important to be aware of the nature of the identified hazards and the solutions currently available to mitigate them.
Previous studies had suggested that desktop 3D printers released minute particle emissions. However, these studies had lacked controlled testing and did not specifically characterize the particles and chemicals emitted. However a two-year investigation conducted by scientists at UL Chemical Safety and Georgia Institute of Technology has provided better information about the nature of the emissions and the consequent impact of desktop 3D printers on indoor air quality. The results were recently published in two separate studies in Aerosol Science and Technology (here and here), and they were not encouraging. Testing had identified hundreds of different compounds, including some known health hazards.
These findings come at a time when these low-cost machines are increasingly appearing in commercial, medical, and educational settings. Marilyn Black, vice president and senior technical adviser at UL and a co-author of both studies, says her team’s findings should serve as a wake-up call, and they’re asking health researchers, scientists, and other institutions to investigate further.
Standard desktop 3D printers produce detectable amounts of ultra-fine particles, or UFPs, while printing. UFPs are nano-scale particles that are invisible to the human eye, but could lead to serious health issues, particularly if inhaled and delivered to the body’s pulmonary system.
“Ultra-fine particles are very fine particles that are less than 0.1 micron (100 nanometers) in diameter,” said Black. “More than 90 percent of the particles we found emitting from 3D printers were in the nanoparticle range. These small particles, when inhaled, can reach the deepest part of the lungs, where they can enter tissues and cells, and can lead to cardiovascular and pulmonary effects in humans.”
When a printing process is initiated, a burst of new particles is created, which then becomes airborne. It’s this initial batch that tends to contain the smallest sizes and the highest UFP concentrations during the entire print, according to the new research.
In tests, the researchers primarily looked at filament fabrication printers that use more common thermoplastics like PLA, ABS and nylons. Specifically, the researchers looked at FDM 3D printers (fused deposition modeling), which are not only the most popular 3D printing technology currently in use, but also known to produce some of the highest levels of UFPs.
Black’s team conducted a small number of toxicity tests on these printers using several methods, including chemical tests and in vitro cellular assays (the use of live cells). ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic Acid) filaments were tested, and all tests indicated at least some level of toxic response, though the toxic response varied by filament type.
As much as the volume was an important finding, the variety of different substances contained in the emissions was of equal importance.
No less than 200 different volatile organic compounds (VOCs) were detected in the invisible puffs emanating from the printers during operation —including many known and suspected irritants and carcinogens. Common VOCs detected included formaldehyde (a carcinogenic organic compound), styrene (a flammable chemical and irritant), and caprolactam (a compound known to cause irritation and burning of the eyes and throat, headaches, confusion, and gastrointestinal problems).
The researchers also documented the different factors involved in the production of UFPs. Factors that affected the types of UFPs produced include the temperature of the nozzle, the type of filament used, the filament and printer brand, and filament color. Factors that affected emission levels included extrusion temperature, filament material, and the filament brand.
“Our research provides technical information on the mechanism for particle formation and shows the operational factors make a difference. This information can assist manufacturers in adapting new technologies and controls to minimize or reduce the emissions.”
It is important to note that this study was not designed to be a detailed look into the long-term health effects of 3D printers. Accordingly, the researchers are now asking scientists to perform complete risk assessments to determine dangerous levels of toxic emissions, while asking manufacturers to do what’s necessary to minimize emissions.
So what solutions are available? How can these concerns be effectively addressed?
The study recommended desktop 3D printers be used in well-ventilated spaces with outdoor air flow. Users are also advised not to stand close to the printer during operation.
The use of filtration systems capable of filtering out VOCs and UFPs can also play a significant role in addressing the problem.
Stand-alone filtration systems are also available and may be an excellent solution for retrofitting existing printer systems to better air quality standards. The ZIMPURE filtration system that can be adapted to fit almost any 3D printer, and the 3DPRINTCLEAN Model 660 enclosure provides air filtration along with excellent thermal controls and security.
The bottom line? Implement these solutions and print safe.