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FEATURE
3D Printing on a Shoestring:
How to Avoid a Costly Ventilation Retrofit
by Wilhelmina Randtke, Lee Bareford, and Alley Tooley
| Libraries wishing to start 3D-printing programs must address safety without clear standards. |
This article is based on our experiences launching a 3D-printing program at Georgia Southern University’s libraries. 3D printers are cheap. However, 3D printing releases fumes, and dedicated ventilation retrofits are expensive. With a limited budget, we wanted to operate safely but without installing costly dedicated ventilation.
Introduction and Overview
3D printing is a rapidly growing industry appealing to a wide audience.1 Academic and public libraries are taking advantage of the affordability and accessibility of 3D printers by acquiring them for patron use. Thermoplastic filament printers are the most popular type used in libraries. They work by feeding a strand of thermoplastic filament through a heating block, melting the plastic, and then extruding it from a nozzle and depositing it in layers that harden to form a solid, 3D object. Filament 3D printers are relatively easy to operate and low-cost. But there are health and safety concerns related to filament printers, including the potential toxicity of ultra-fine particles (UFPs) and volatile organic compounds (VOCs) emitted during the printing process. Exposure to UFPs and VOCs in high concentrations over an extended period of time increases the risk of adverse health effects, which include respiratory irritation, eye irritation, headache, shortness of breath, and other symptoms while, or shortly after, operating one or more of these printers.2
The amount of UFPs and VOCs emitted during printing varies among the types of filament used. The three most common types of thermoplastic filaments are acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and nylon. While each of these filaments emits UFPs and VOCs, several studies indicate that ABS and nylon emit considerably higher concentrations of UFPs and VOCs than PLA.3 A study by Chan et al. showed that PLA filament could be used in up to three simultaneously operating 3D printers in a small room without UFPs and VOCs exceeding industry-established safe exposure limits.4 PLA is the widely recommended type of filament to use in order to minimize health and safety concerns of fumes. However, all research consulted for this article identified the need for further testing and research.
Due to the limited research into the detrimental health effects of 3D-printer emissions to date, authorities such as the American National Standards Institute (ANSI)5 and the National Institute of Occupational Safety and Health (NIOSH)6 recommend that 3D-printer operators wear personal protective equipment, ensure that the 3D printer and its surrounding work area are clean and dust-free, and use 3D printers in ASHRAE-certified ventilated rooms away from high-traffic areas. Of these recommendations, providing dedicated ventilation is the most significant challenge to libraries due to costs. In contrast to the low prices of 3D printers, dedicated ventilation is astronomically expensive. The Creality 3D printers used at Georgia Southern University’s libraries cost less than $300 each, but laboratory-quality ducted fume hoods can cost $1,200–$2,500 per square foot.7 Installation costs for dedicated ventilation in a single room can cost in the middle five-figure range. In order to launch a 3D-printing program on a shoestring budget, we identified limitations to allow safe printing without retrofitting ventilation. We researched workplace safety rules, government regulations, and environmental health and safety (EHS) policies at other institutions, and we connected with our campus EHS office for assistance in assessing spaces and safety considerations.
Safety Regulations: Coming Soon, but Not Here Yet
While 3D printing is now widespread and affordable, safety regulations haven’t quite caught up. With most potential hazards, determining safety doesn’t require detailed research. In most fields, regulators such as the Occupational Safety and Health Administration (OSHA) have published standards that are quickly located and easy to apply. However, 3D printing is new enough that similar, easy-to-find safety regulations are not yet available. At the time of this writing, the closest thing to a governmental safety regulation is NIOSH’s informational poster, 3D Printing With Filaments: Health and Safety Questions to Ask.8 This poster lists several 3D-printing safety recommendations, including limiting exposure to UFPs and VOCs by using PLA instead of ABS. It identifies using a dedicated ventilation system as a best practice, regardless of printing method or filament type. The poster recommends dedicated ventilation for finishing work such as grinding rough parts and spray-painting, so at least some anticipated emissions occur outside of the actual printing process.
Meanwhile, workplace safety standards are coming, but likely not for years. In 2016, the International Standards Organization (ISO) and the American Society for Testing and Materials (ASTM) began drafting safety standards for 3D printing.9 The joint ISO and ASTM group will establish 3D-printing standards across all aspects of 3D printing, not just safety. To give a feel for the speed with which safety standards might be published and what ISO and ASTM prioritize, the standards organizations released their first 3D-printing safety standard, ISO/ASTM DIS 52931 (a 3D-printing standard for printing with powdered metals) in draft form on Dec. 2, 2021.10 The 5-year development period of this draft standard demonstrates the pace at which industry standards will develop and shows prioritization of the most dangerous materials first. For example, since metal powder is universally recognized as more dangerous than plastic fumes, the standards organizations have prioritized it. ISO and ASTM are researching plastic filament toxicity in partnership with Georgia Tech, but it can be expected that a standard for plastic filaments is years away. This research group released a standard for how to do testing and measure fumes, but it has not yet developed any standard on safe levels of fumes.11 Government regulators such as OSHA will likely wait for standards to be published before adopting them. Easy-to-look-up safety standards on plastic filament fumes are likely years away. In the meantime, libraries wishing to start 3D-printing programs must address safety without clear standards.
3D Printing Without Dedicated Ventilation: Limitations to Expect
To reduce the possibility of the health and safety impacts of 3D printing, libraries can commit to some limitations on 3D-printing programs.
Print Only With PLA
As mentioned previously, the vast majority of published research indicates that printing with plastic filament is safest and that PLA is the least-toxic filament. Filaments such as ABS and nylon that print at higher temperatures release more UFPs and VOCs than PLA, which prints at lower temperatures.12 However, PLA has significant limitations. Unlike ABS—which is used to produce long-lasting, durable items such as milk crates, aircraft parts, and prosthetics—PLA is short-lived and weak. PLA tends to absorb moisture from the air and become brittle over time, which is why PLA filament is shipped in a vacuum-sealed package with a silica gel packet enclosed. Filament exposed to air can quickly degrade and become too brittle to print with. This also affects printed items, which absorb moisture from the air over time. Prints with intricate, interlocking, or movable pieces are especially susceptible to breakage. PLA can work for decorative objects or prototypes, but it is not the best choice for fabricating durable, reliable, and precisely made materials.
Measure Existing Ventilation
Choosing the space with the best existing ventilation to locate 3D printers is another low-cost mitigation strategy. Policies released by university EHS offices can help identify ways to reduce risks. The table on page 26 lists EHS policies that we reviewed. Most policies allow only two types of filament to be used without dedicated ventilation: PLA and polyvinyl alcohol (PVA). PLA is used for structural printing, while PVA is used for scaffolding only—which is to say, it’s used to support other materials during the printing process, but then removed and discarded after printing. Essentially, without a ventilation retrofit, PLA is the only option allowed under most EHS policies. For PLA printing without dedicated ventilation, EHS policies stipulate a minimum of anywhere between four and 12 air changes per hour. Measuring air changes per hour and picking a space with sufficient existing ventilation is a low-cost way for a library to mitigate risks.
Working With Your EHS Office
Librarians tend not to have backgrounds in chemical exposure or ventilation, but Georgia Southern University’s EHS office has employees who do. Any academic library that is part of a bigger system should have similar access to an EHS office. Public libraries should have access to an EHS office through their city government. EHS offices can assist in connecting employees with applicable workplace safety standards, writing policies, and structuring work to minimize risk.
At Georgia Southern University, the libraries did preliminary research, opted to limit printing to PLA only, and approached EHS with a request to measure air changes per hour in the spaces that we might want to use for 3D printing and for an assessment of the safety of printing with PLA specifically. Measuring air changes had a prompt turnaround time. Finalizing a 3D-printing safety policy is a long process and is not yet complete. We suspect our EHS office prioritizes the most dangerous situations and that, based on our pre-work and limitations, the libraries’ plans for 3D printing didn’t raise any immediate health and safety concerns.
Although getting a 3D-printing policy was slow going, we did get prompt and useful assistance from EHS. They promptly connected us to university HVAC technicians who measured air changes per hour in potential 3D-printer locations at the libraries. This was extremely helpful in identifying specific spaces that would work for our program. For example, the libraries had recently discontinued hosting servers in-house. This left an empty server room featuring a massive air conditioning system that blasts air like a windy day. HVAC technicians nixed this room immediately because the system is designed only to cool the air, not ventilate. As a result, the server room has a very low rate of air changes per hour. Essentially, that space would become an air-conditioned hot box that would trap 3D-printer emissions. A short visit from the HVAC technicians allowed us to identify which spaces had the most air changes per hour. We had been concerned about locating the printers near a busy entryway, because it would expose high-traffic areas to emissions, but HVAC technicians estimated that area to have more than 40 air changes per hour.
We recommend that libraries connect with an EHS program early and get input before planning or launching a 3D-printing program. EHS staffers have the skills to assess existing physical spaces, read through scientific research on toxicity, and know the difference between an acceptable risk and a serious, unacceptable hazard. Connecting with EHS during the planning phase ensures that libraries will later have the support of their institution, that potential costs will be fully known, and that expectations about a 3D-printer program can be managed around the limitations inherent in not having a budget for dedicated ventilation.
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Endnotes
1. PR Newswire. (July 27, 2021). “3D Printing Market Worth $34.8 billion by 2026—Exclusive Report by MarketsandMarkets.” PR Newswire. prnewswire.com/news-releases/3d-printing-market-worth-34-8-billion-by-2026--exclusive-report-by-marketsandmarkets-301341846.html.
2. Chan, F.L., House, R., Kudla, I., Lipszyc, J.C., Rajaram, N., and Tarlo, S.M. (2018). “Health Survey of Employees Regularly Using 3D Printers.” Occupational Medicine, 68(3), 211–214.
3. Mohammadian, Y. and Nasirzadeh, N. (2021). “Toxicity Risks of Occupational Exposure in 3D Printing and Bioprinting Industries: A Systematic Review.” Toxicology & Industrial Health, 37(9), 573–584. doi.org/10.1177/07482337211031691.
4. Chan, F.L., Hon, C.Y., Tarlo, S.M., Rajaram, N., and House, R. (2020). “Emissions and Health Risks From the Use of 3D Printers in an Occupational Setting.” Journal of Toxicology and Environmental Health, Part A, 83(7), 279–287.
5. Chemical Insights. (2021). “3D Printer Safety: A Guide for Institutions of Higher Education to Support Indoor Air Quality & Human Health.” Retrieved from hub-media.aashe.org/uploads/509-Toolkit_Higher_Ed_012221.pdf.
6. Glassford, E., Dunn, K.L., Dunn, K.H., Hammond, D., and Tyrawski, J. (March 2020). 3D Printing With Filaments: Health and Safety Questions to Ask (DHHS NIOSH Publication Number 2020–115). National Institute for Occupational Safety and Health. cdc.gov/niosh/docs/2020-115.
7. National Laboratory Sales. (2022). “How Much Does a Fume Hood Cost?” nationallaboratorysales.com/blog/how-much-does-a-fume-hood-cost.
8. Glassford, E., Dunn, K.L., Dunn, K.H., Hammond, D., and Tyrawski, J. (March 2020). 3D Printing With Filaments: Health and Safety Questions to Ask (DHHS NIOSH Publication Number 2020–115). National Institute for Occupational Safety and Health. cdc.gov/niosh/docs/2020-115.
9. Naden, C. (Oct. 7, 2016). “ISO and ASTM International Unveil Framework for Creating Global Additive Manufacturing Standards.” iso.org/news/2016/10/Ref2124.html.
10. ISO/ASTM DIS 52931:2021. (2021). “Additive Manufacturing of Metals—Environment, Health and Safety—General Principles for Use of Metallic Materials.” ASTM International, West Conshohocken, Pa., standards.iteh.ai/catalog/standards/cen/3a664163-038a-4816-8a97-18cfcb075c84/pren-iso-astm-5293.
11. Underwriters Laboratories. (Feb. 5, 2019). Underwriters Laboratories Publishes ANSI/CAN/UL 2904 Standard for 3D Printers. ul.org/news/ul-publishes-ansicanul-2904-standard-3d-printers.
12. Zhang, Q., Pardo, M., Rudich, Y., Kaplan-Ashiri, I., Wong, J.P.S., Davis, A.Y., Black, M.S., and Weber, R.J. (Jan. 1, 2019). “Chemical Composition and Toxicity of Particles Emitted From a Consumer-Level 3D Printer Using Various Materials.” Environmental Science & Technology, 53(20), 12054–12061. doi.org/10.1021/acs.est.9b04168. |
