Characterizing 3D Printing Emissions and Controls in an Office Environment
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3D printing or additive manufacturing allows users to “print” a variety of items, from airplane parts to prosthetic limbs. 3D printing is still a relatively new technology and there are many gaps in the information available about health and safety implications. As with many innovations, workers are the first groups exposed to potential hazards. Based on prior knowledge from air pollution research and industrial processes (e.g., welding) there are concerns over 3D printing emissions and their potential impact on workers’ health.
MakerBot, a Brooklyn-based manufacturer of 3D printers, has partnered with the NIOSH Nanotechnology Research Center (NTRC) Advanced Materials and Manufacturing field team to conduct measurements to characterize 3D printer emission rates. Several MakerBot 3D printer models and types of filament were evaluated. The thermoplastic filament materials used in the 3D printers at the time of the study included True Orange PLA (polylactic acid), True Yellow ABS (acrylonitrile butadiene styrene), and Slate Grey Tough PLA (impact-resistant PLA).
At MakerBot, the NIOSH field team used two different methods to evaluate and compare emissions. The field team evaluated particulate and volatile organic compounds (VOCs) emitted from simultaneous operation of up to 20 desktop 3D printers in a conference room. Emissions from individual 3D printers were also evaluated using a portable isolation chamber developed by NIOSH researchers. Methods included:
- collecting filter-based area air samples for detection of fine and ultrafine particulate by electron microscopy and gravimetric methods;
- collecting area air samples for VOCs using charcoal tubes, vacuum cylinders, and direct reading instruments;
- using direct reading data logging particle counters to monitor the number and size classes of airborne particles.
Findings
During 3D printing, respirable particulate concentrations were non-detectable (below 0.03 micrograms per cubic meter, µg/m3) and VOC concentrations were well below applicable occupational exposure limits (OELs). Particulate and VOC concentrations measured in the conference room during 3D printing with 20 printers were much lower than those measured in the test chamber. This was likely due to general dilution as a result of the conference room’s larger ventilated space compared to the enclosed test chamber. However, local exhaust ventilation could reduce or eliminate the concentrations of ultrafine particle emissions that were measured in the conference room.
Another key finding of our study was that True Orange PLA filament produced lower ultrafine particle emissions compared to published results from other emission tests in the scientific literature such as He, et al [2007], Stephens et al. [2013], and Stefaniak et al. [2017]. However, additional research should be conducted to identify other lower emitting filaments as an option to reduce ultrafine emissions in the workplace and to develop a system to categorize 3D printer emission rates.
Occupational exposures and potential exposure-related health effects associated with 3D printing/additive manufacturing are areas that require further evaluation and research. There are currently no OELs for 3D printer emissions and potential toxicological effects of exposure to emissions from 3D printing are not fully understood. While more information is being gathered and assessed related to these issues, we recommend the following actions to reduce potential for uncontrolled emissions from filaments used in the 3D printers.
Recommendations
Our recommendations are based on an approach known as the hierarchy of controls, and would be applicable for all brands of 3D printers and filaments. This approach groups actions by their likely effectiveness in reducing or removing hazards. In most cases, the preferred approach is to eliminate hazardous materials or processes and install engineering controls to reduce exposure or shield employees.
- Ventilation is an important engineering control to help control/reduce emissions from 3D printers. Examples of ventilation controls could include single unit local exhaust ventilation system, snorkel fume extractors, or for situations where multiple printers are used, operating 3D printers on enclosed ventilated racks that exhaust to the outdoors may be appropriate. These ventilation approaches may reduce energy costs compared to general dilution ventilation. Because the majority of 3D printer emissions are nanoparticles, another option would be to exhaust the air from printers through a room air cleaner equipped with high-efficiency particulate air (HEPA) filtration.
- More research is needed to identify additional low emitting filaments for use in 3D printers so that filament selections can be made based on low emission rate in addition to other filament properties. Low emitting filaments will reduce energy costs associated with ventilation and filtration controls and may be particularly important for workplaces in leased facilities or other settings where ventilation modifications are not feasible or allowable.
- Integrate local exhaust duct connections and/or particulate filtration into the design of individual 3D printers to reduce ultrafine particle emissions into the indoor work environment.
Use of 3D printers is likely to continue to increase. As much remains unknown about 3D printer emissions, NIOSH would like to conduct further evaluations and research to assess additional additive manufacturing scenarios, processes, or exposures. Please contact Kevin L. Dunn at kgd8@cdc.gov or use the comment box below if you are interested in collaborating with NIOSH on this work.
Kevin L Dunn, MS, CIH, is the Advanced Materials and Manufacturing Field Team leader in the NIOSH Division of Surveillance, Hazard Evaluations and Field Studies.
Duane Hammond, MS, PE, is a Mechanical Engineer in the NIOSH Engineering and Physical Hazards Branch.
Jennifer Tyrawski, PhD, is a Health Communication Specialist in the NIOSH Division of Surveillance, Hazard Evaluations and Field Studies.
Matthew G. Duling, MS, REHS, is an Industrial Hygienist in the NIOSH National Personal Protective Technology Laboratory, Evaluation and Testing Branch.
References
He, C. Morawska, L. and Taplin, L. [2007]. Particle Emission Characteristics of Office Printers. Environmental Science & Technology 2007 41 (17), 6039-6045 .DOI: 10.1021/es063049z
Stephens, B. Azimi, P. El Orch, Z. Ramos, T. Ultrafine particle emissions from desktop 3D printers. Atmospheric E nvironment 2013 (79) 334-339. https://doi.org/10.1016/j.atmosenv.2013.06.050
Aleksandr B. Stefaniak, Ryan F. LeBouf, Jinghai Yi, Jason Ham, Timothy Nurkewicz, Diane E. Schwegler-Berry, Bean T. Chen, J. Raymond Wells, Matthew G. Duling, Robert B. Lawrence, Stephen B. Martin Jr., Alyson R. Johnson & M. Abbas Virji (2017) Characterization of chemical contaminants generated by a desktop fused deposition modeling 3- dimensional Printer, Journal of Occupational and Environmental Hygiene, 14:7, 540-550, DOI:10.1080/15459624.2017.1302589
28 comments on “Characterizing 3D Printing Emissions and Controls in an Office Environment”
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It is really interesting blog. You are giving good and beautiful 3d printing info. Thanks for this.
thanks for the heads up Good Blog, very usefull
Thank for sharing
You have discussed an interesting topic that everybody should know. Very well explained with examples.
Very helpful article thanks.
Hello, I conducted an assessment of our universities 3D printing lab for my graduate capstone project and came to the same conclusion. We are working on determining if the printers are cause for elevated levels of Ozone in the lab. Please reach out if you wish to learn more about the study which we conducted.
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Thank You For Sharing this Article
Really this is awesome tips sir thanks for guiding me
Very informative and helpful post. Thanks for this sharing with us.
We conducted testing in an office environment as well, and came to a same / similar conclusion. What I’m curious about is, how are other organizations controlling filaments other than PLA? i.e. carbons / kevlars / metals, etc.
We haven’t gone that direction, but there is interest. Would a set up with a vacuum table (similar to a nail table, or machine table) with a poly cover over it, and the particulates being vacuumed in to a bag house of some sort? What kind of designs are being used? Filtration systems? Are there good resources available for learning?
Obviously we can see and read SDS’s, but how are people controlling the hazardous ultra-fine particulates when they don’t follow general air flow patterns?
Good Morning TC,
Thank you for the comment and question. Here at NIOSH we are focusing our research on developing ways to control exposures based on print method rather than material feedstock. For example, there are many possible filament options in fused filament fabrication (FFF) printing, and the potential risks of these materials is still being researched. Thus, we are working on engineering controls to reduce or eliminate ultrafine emissions at the print head, regardless of filament material. In our work, we are finding that local exhaust ventilation with high-efficiency particulate air (HEPA) filtration is effective.
Many of the sites we have visited are also controlling 3D printer emissions by using enclosures or other local exhaust ventilation solutions combined with HEPA filtration or exhausting air to the outdoors. However, we appreciate your question about whether using vacuum tables, machine tables, and poly covers would be appropriate. These or similar engineering controls that protect workers by controlling the source of hazardous materials or isolating the worker from the hazard, could be effective control strategies. The use of HEPA filtration should provide a good approach to capturing nanoparticles. Work practices, such as limiting access to printing areas, observing printing from a remote location via a camera feed, and waiting several minutes before approaching the machine when there is a print failure, could also reduce the potential for exposure to ultrafine particulate.
We are currently working on several products related to controlling hazards when working with 3D printing technologies, including metal powder printing and FFF printing. These products will be similar to our nanomaterials guidance found here: https://www.cdc.gov/niosh/docs/2018-103/default.html
Again, thank you for the comment and watch for several new NIOSH publications and products to be released in the next few months.
Good question. I would like to see some kind of recommendations for size of filter/exhaust system for a given printer type and build volume.
Thanks Very Helpful Content.
This is very helpful in future, really informative post.
Good morning! I am writing to request permission to reprint the information this blog in a newsletter for public schools (primary and secondary schools). Full credit will be given of course. I appreciate your consideration.
Please feel free to reprint this information. You may also be interested in the blog Potential Hazards of Additive Manufacturing http://blogs.cdc.gov/niosh-science-blog/2019/04/09/am
Very simpely and usefull content.
Hello! Has there been any development on HEPA filter effectiveness for the UFP’s, as there is a debate on how well they work with the sub 0.3 micron particles (smallest size listed for filter effectiveness)? This would be very helpful for office / home applications where filtering outside is not an option.
This is something very important and useful topic to discuss. Great article.
Nice post.
Hello. Very informative article. I wonder do you have any recommendations for the ventilation system (ACH rates) that exhausts air to the outdoors? I appreciate your reply.
General ventilation and filtration provided by heating, ventilating, and air-conditioning (HVAC) systems can reduce the airborne concentration of ultrafine particles and VOCs in makerspaces and other locations where 3D printers are in use. However, implementing local exhaust ventilation controls to capture and reduce emissions near the source of generation is often the preferred approach and typically results in much lower airborne concentrations while consuming less energy compared to increasing the general dilution ventilation. The amount of ventilation needed in a makerspace may also depend on a number of other factors such as the number and type of 3D printers, the filaments or feedstock in use, post processing equipment and chemicals used, as well as other manufacturing processes used in the surrounding work environment. Additionally, some manufacturers of additive manufacturing or 3D printing equipment include recommended ventilation improvements and ACH rates with their equipment installation guides. Collaborating with your facility management team and the environmental health and safety department at your facility is an important first step before setting up a maker space in any work environment or before deciding on improvements to your ventilation system. Finally, it is important to rely on applicable codes and industry standards before deciding on improvements to your facility HVAC system. For example, ANSI/ASHRAE Standards 62.1 and 62.2 are commonly used industry standards for ventilation system design and acceptable indoor air quality (IAQ). ANSI/ASHRAE Standards 62.1 and 62.2 were recently updated in 2019 and specify minimum ventilation rates and other measures to minimize adverse health effects for occupants.
3d printing uses are at a greater pace and none can deny this. Especially this COVID contribution of 3d printing is much higher
The covid-19 has created a wide range of opportunities for the 3D printing market.
I read your article very carefully. I think you should also write article about 3d metal parts. This will be beneficial for others i guess thank you.
Very useful post i really appreciate thanks for sharing such a nice post.
Great article, I have not considered how desktop 3D printers impact VOC’s, with all of the printers I have used they are never ventilated. I enjoyed the research and data that went into this study. I also recently found a blog that talked about all of the different filaments, and it made me wonder how VOCs impact the many different types of filament that is on the market. Have you thought about doing a study on other materials?
I understand the particulate matter. How about the IPA cleaning part? Does anyone have any recommendations for that in NY State? I was asked by my Engineers about a new printer that we are purchasing, and it holds 11.4 gallons of Isopropyl. Any thoughts on how to handle that?
Thank you for the question. Generally, we have not observed high air concentrations of isopropanol, however with heavy use like you have described, hazards can include inhalation, dermal, and eye contact. These would likely be dependent on the duration of use and way the isopropanol is used (e.g., closed system or open system). Solvents should be used in an area with adequate ventilation and with appropriate gloves and eye protection for chemical handling and other activities. Isopropanol and other similar solvents are flammable, and precaution should also be taken for receiving and storage of flammable materials. Associated vapors can create an explosion hazard in areas with inadequate ventilation. The new NIOSH guidance document Approaches to Safe 3D Printing: A Guide for Makerspace Users, Schools, Libraries and Small Businesses (cdc.gov) has a brief section (3.6) on solvent use.
Since your equipment and work environment are specific to your site, performing a job hazard analysis for the tasks needed to service and operate your equipment will help identify safety and health hazards and prevention control measures. Some resources for performing this analysis include: Safety Management – Hazard Prevention and Control | Occupational Safety and Health Administration (osha.gov) and Identifying Hazard Control Options: Job Hazard Analysis (osha.gov).
There are NY state requirements and there may be local requirements as well, regarding flammable and combustible liquids (e.g., Fire Code of New York State). If you have a company Environment, Health and Safety team, you should consult them to ensure compliance with these requirements.