» 3D Printing–Is It Safe for the Earth? Is It Safe for Us? Angles (2024)

Wouldn’t it be cool to live in a 3D-printed house? It turns out you can, thanks to technology created by Behrokh Khoshnevis, a professor at the University of Southern California. In a 2012 TEDx talk, Khoshnevis spoke about a process he pioneered, in which a robot would squeeze cement out of a nozzle like toothpaste to form a house, layer by layer. Traditional construction of houses requires many materials, which results in a lot of waste. In addition, the machinery used to construct a house emits harmful gases into the air. One of the bolder claims that Khoshnevis makes is that unlike traditional construction, “there will be no waste in construction” with the new method (Contour 2017). This is just one example of the claims that 3D printing is safer for the environment and for humans than traditional manufacturing and construction methods. But how trustworthy are these claims?

Although 3D printing of houses is an ambitious idea, the term 3D printing more commonly refers to desktop 3D printing, in which a tabletop machine uses melted plastic to form shapes. The environmental claims linked to 3D printing of houses parallel the claims linked to tabletop 3D printing.

Although 3D printing technology has been around for a few decades, usage of the technology has grown rapidly in the past few years. It is becoming increasingly popular among educators and hobbyists, and desktop 3D printers are becoming more broadly available. Despite the rise in popularity, however, there is little information about the environmental impact of 3D printing. So, until further research is conducted, we only have small-scale experiments to rely on for this information.

Is It Safe for the Earth?

A major environmental concern about 3D printing is that it uses plastics to create shapes. In particular, the usage of support material can make 3D printing wasteful. Support material is simply plastic that is printed before the actual part to make sure the shape of the part matches what the user wants.

This support material is useless after printing, so it is usually thrown away. For this reason, 3D-printing instructors will likely advise users to employ the smallest amount of support material. However, it is impossible to completely avoid throwing away 3D-printed plastic, and this plastic ends up with the other plastic wastes that the world creates – in landfills and oceans. In 2010, it was calculated that 5 to 10 million metric tons of plastic waste entered the ocean, but those numbers are expected to be ten times higher by 2025 if things don’t change (Jambeck 2015). Although the waste from 3D printing only makes up a small portion of the world’s total plastic waste, every contribution has an effect, and the waste caused by 3D printing will only grow with the popularization of the technology.

One obvious solution to the problem of waste associated with 3D printing is to find better ways to recycle 3D-printed plastics. This solution can be seen in the growing popularity of polylactic acid (PLA). PLA is a popular plastic to print with, and the thing that makes it special is that it is theoretically biodegradable. However, it is only barely so. To properly degrade, PLA has to be exposed to certain enzymes at certain temperatures and just the right pH, and even then, it could take months before the material has completely degraded (Lee 2014). To make this problem worse, there are not many places that recycle PLA. For example, as a student at MIT, I have found that 3D printing plays a big role in education here. There is a program called MakerLodge that educates first-year MIT students in how to use workshop machines, including 3D printers. Naturally, there are many 3D printers located all around campus. However, when I asked the MIT Environment, Health & Safety department about recycling 3D plastics, they said that PLA “is technically compostable. That said, MIT’s organics management program is for food waste only” (Kelly 2017). Even with the abundance of 3D printers, MIT doesn’t collect PLA to degrade it. This means that all of the scrap PLA heads towards landfills, which lack the conditions to properly break it down.

Despite the environmental concerns about the plastics used in printing, there are claims that altogether, 3D printing is better for the environment than CNC (computer numerical control) milling, which is very popular among hobbyists and manufacturers due to its speed. CNC milling uses a computer-controlled tool to carve a shape out of material. The bits of material that are carved away from the original shape end up as waste. A study conducted at the University of California at Berkeley compares the environmental impact of CNC milling to 3D printing, measured in ReCiPe points (the more points a process has, the more negative its effect on the environment). This study shows that, although the waste produced by 3D printing has a smaller effect on the environment than CNC milling, the difference is very slight (Faludi 2015).

This slight difference is not only in the waste produced, but also in the electricity required to run the machines. From this, we can conclude that, when it comes to the environment, 3D printers and CNC mills have very similar impact.

As the UC-Berkeley study shows, the most environmentally harmful thing about CNC routing is the electricity that is required to run it. This electricity is generated by fossil fuels, so the large consumption of electricity means the large consumption of fossil fuels and the emission of greenhouse gases into the air, causing a significant change in the climate. Together, these factors create an incentive to find a more energy-efficient method of creating 3D parts. Unfortunately, 3D printing requires the same electricity as CNC routing, so the search for more energy-efficient methods must continue.

Is It Safe for Us?

In addition to the issues of waste and energy consumption, the fumes produced in 3D printing may pose distinctive health risks.

In addition to the issues of waste and energy consumption, the fumes produced in 3D printing may pose distinctive health risks. 3D printing requires melting plastic and pushing it through a nozzle to form layers of plastic. The heating of plastic breaks apart some of the plastic molecules into smaller parts, which end up floating in the air around the printer. Arguably the most concerning example involves the widely used plastic ABS, composed of acrylonitrile, butadiene, and styrene (Lenau 2003). When heated to high temperatures, ABS molecules split apart into these smaller components, which are then emitted into the air. Each of the three components has its own degree of toxicity. Workers who are chronically exposed to acrylonitrile have a significantly increased risk of developing lung cancer. In addition, there is already a report of a child dying from respiratory malfunction due to breathing in acrylonitrile (U.S. EPA 2000a). Butadiene is known to be a human carcinogen and to increase the risk of heart disease (U.S. EPA 2000b). Inhaling styrene particles is known to cause damage to the central nervous system (U.S. EPA 2009). The health risks of 3D printing are not significant for the occasional user of 3D printers. However, those who use 3D printers frequently should consider how much they’re being exposed to these particles.

A group of scientists at the Illinois Institute of Technology (IIT) did a small experiment on the emission of these particles due to 3D printing. In this experiment, they measured how many particles were being emitted in a room with five active 3D printers. What they found was that within 25 minutes of run-time, the space around the 3D printers had a concentration of 150,000 particles per cubic centimeter, enough to classify them as “high emitters” of these particles. The IIT group also compared the number particles released from 3D printing to the number of particles released from cooking – there are carcinogens that have been identified in the fumes caused by cooking meats (Seow 2000). The experiment shows that an individual desktop 3D printer emits these particles at a rate that is very similar to cooking meat indoors (Stephens 2013)

In addition to the high emission of particles, the time required to print objects creates another concern for 3D printers. All3DP.com, a 3D-printing informational site, features an article by Franz Grieser in which he compared how long it took to 3D print various models. One of the models he used for comparison was a 6x3x5 centimeter boat, small enough to fit in the palm of your hand. This small boat takes 2 hours to 3D print (Grieser 2016). At this rate, printing larger parts could require printing for more than 24 hours.

The combination of the high emission of the small particles and the long printing time makes 3D printing a potentially hazardous process, for the environment and humans alike. Someone cooking for long periods of time would be likely to turn on the hood vent above the stove, or at least to open a nearby window. Similarly, it would be appropriate to provide ventilation when 3D printing. However, most desktop 3D printers sold for hobbyists are stand-alone printers and don’t come with a ventilation system. This lack of ventilation could pose a risk to those who frequently use 3D printers.

Soare 3D printers safe enough for people to be buying them and putting them in their homes? If hobbyists or students are looking to create physical models of their ideas, should they stick with traditional methods or turn to 3D printing for the sake of the environment? Without more research on the subject, there’s not a clear answer to that question. However, the evidence we do have suggests that it would be best to look further into the issue, especially with the increasing popularity of 3D printing.

Works Cited

Contour Crafting Corporation. (2017). Building Construction. Retrieved December 03, 2017, from http://contourcrafting.com/building-construction/

Faludi, J., Bayley, C., Bhogal, S., & Iribarne, M. (2015). Comparing environmental impacts of additive manufacturing vs traditional machining via life-cycle assessment.Rapid Prototyping Journal,21 (1), 14-33. doi:10.1108/rpj-07-2013-0067

Grieser, F. (2016, April 15). 3D Printing Speed: How Fast Can 3D Printers Go? Retrieved December 03, 2017, from https://all3dp.com/3d-printing-speed/

Jambeck, J. R., Geyer, R., Wilcox, C., Siegler, T. R., Perryman, M., Andrady, A., . . . Law, K. L. (2015). Plastic waste inputs from land into the ocean.Science,347(6223), 768-771. doi:10.1126/science.1260352

Kelly, N. (2017, December 12). Email.

Khoshnevis, B. (2012). “Contour Crafting: Automated Construction: Behrokh Khoshnevis at TEDxOjai.” YouTube, YouTube, 28 Apr. 2012,www.youtube.com/watch?v=JdbJP8Gxqog.

Lee, S. H., Kim, I. Y., & Song, W. S. (2014). Biodegradation of polylactic acid (PLA) fibers using different enzymes. Macromolecular Research, 22(6), 657-663. doi:10.1007/s13233-014-2107-9Lee, S. H., Kim, I. Y., & Song, W. S. (2014). Biodegradation of polylactic acid (PLA) fibers using different enzymes.Macromolecular Research,22(6), 657-663. doi:10.1007/s13233-014-2107-9

Lenau, T. (2003). ABS – acrylonitrile butadiene styrene. Retrieved December 09, 2017, from http://designinsite.dk/htmsider/m0007.htm

Seow, A., Poh, W. T., Teh, M., Eng, P., Wang, Y. T., Tan, W. C., . . . Lee, H. P. (2000). Fumes from meat cooking and lung cancer risk in Chinese women.Cancer Epidemiol Biomarkers Prev.,9(11), 1215-21. Retrieved January 12, 2018, from øhttps://www.ncbi.nlm.nih.gov/.

Stephens, B., Azimi, P., Orch, Z. E., & Ramos, T. (2013). Ultrafine particle emissions from desktop 3D printers.Atmospheric Environment,79, 334-339. doi:10.1016/j.atmosenv.2013.06.050

U.S. EPA. (2000a, January). Acrylonitrile. Retrieved December 9, 2017, from https://www.epa.gov/sites/production/files/2016-09/documents/acrylonitrile.pdf

U.S. EPA. (2000b, January). Styrene. Retrieved December 9, 2017, from https://www.epa.gov/sites/production/files/2016-09/documents/styrene.pdf

U.S. EPA. (2009, March). 1,3-Butadiene. Retrieved December 9, 2017, from https://www.epa.gov/sites/production/files/2016-08/documents/13-butadiene.pdf