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Circular Economy

Assembly Plant
Photo Credit: The Chrysler 200 Factory Tour, an interactive online experience using Google Maps Business View technology, takes consumers inside the new 5-million-square-foot Sterling Heights Assembly Plant for a behind-the-scenes peek at how the 2015 Chrysler 200 is built.



An unsustainable economy (i.e., an economy that expends limited effort to preserve resources) is, typically, a result of decisions made by individuals and firms from their stakeholder perspective. It develops primarily as a result of a misalignment of incentives where those that bear the costs of increased sustainability do not receive commensurate benefits. Successful solutions to this problem will tend to alter the economy so that the logical and rational outcome for the individual or business matches that of society. Alternatively, successful solutions might mitigate negative outcomes. NIST AMS 100-48 focuses on standards and technologies as a solution to facilitating a more sustainable economy. Four means of achieving sustainability are identified: increasing product longevity, reusing/repairing products, reducing material and energy use, and recycling.

Product Life Expectancy and Repairability


Extending the useful life of products is an effective means for reducing environmental impact for durable goods (e.g., automobiles, machinery, computers, and appliances). Three means for extending the use of a product is to design the product to last longer, reusing a product, and repairing a product rather than discarding it. A 50 % increase in life expectancy of a product decreases the needed replacements by up to approximately 33 %, which can equate to a 33 % reduction in environmental impact to produce that type of good and a potential savings of up to $316.6 billion in U.S. consumer savings. A 100 % increase in life expectancy reduces needed replacements by up to 50 %, which can equate to up to a 50 % reduction in environmental and up to $474.9 billion in savings. Note that these are upper bound estimates. Producers have limited means for signaling their product has a longer life expectancy, likely resulting in decreased sales of long-life expectancy products. The following needs were identified:

  • Ability to differentiate product brands and models by life-expectancy
  • Ability to differentiate product brands and models by repairability

The ability to differentiate quality products can increase the longevity of products, thereby reducing environmental impact, benefit consumers by not having to replace products as frequently, and disproportionally benefit U.S. manufacturers, as they likely have a tendency to use differentiation as a competitive strategy. Energy Star is an example of successfully differentiating products. In the case of Energy Star, it is by the amount of energy the product consumes. It is estimated that for every dollar invested into Energy Star, there are $350 in energy savings (U.S. Environmental Protection Agency and U.S. Department of Energy 2022). In 2020 alone, Energy Star helped save $42 billion in energy costs (U.S. Environmental Protection Agency and U.S. Department of Energy 2022). This program addresses a problem that is similar to differentiating by life-expectancy in that both can harness the savings that consumers experience in order to reduce environmental impact.

The type of differentiation that Energy Star facilitates can also be used to extend the useful life of products. The ability to differentiate by life-expectancy is similar to the potential NIST action item in NIST Special Publication 1500-204 regarding expected lifetime certification. There are many needs for extending product longevity; however, differentiating products by life-expectancy and repairability stands out as it can motivate manufacturers and consumers to work toward solving the other challenges. That is, it can have a chain reaction. Additionally, other efforts to increase life-expectancy and repairability may have limited impact if manufacturers have little or no incentive to lengthen the useful life of a product and consumers have no ability to select the longer lasting products.



Recycling is an additional avenue for decreasing environmental impact. Two key topics are plastics and metals which are a limited resource that often contaminate the environment when discarded; constitute a significant amount of the material in technology products, including electronics, automobiles, and appliances; and they are often recycled at a low rate.

Plastics Recycling

Currently, a mere 8.7 % of plastics are recycled (U.S. Environmental Protection Agency 2021). It is estimated that if we recycled all plastics it would result in a 25 % decrease in carbon equivalent emissions (Zheng and Suh 2019). However, the cost of using recycled plastic material can be as much as twice as high as virgin material for some applications. Virgin plastic is sourced from raw materials that are concentrated at relatively few locations while recycled material is widely dispersed, combined with other materials, and often contaminated. An analysis revealed that 20 % of plastic collection efforts had a 15 % return on investment or higher for recycling, 50 % had positive returns but were less than the selected 15 % threshold for investment, and 30 % had negative returns (Gao 2020). There are many challenges to recycling plastic: the material typically degrades after being mechanically recycled, there are problems with contamination, there are many types of plastic that cannot be recycled together limiting economies of scale, plastics are often integrated into a product with other material types (e.g., metal), and there are many variations in additives that need to be addressed. Additionally, there is not always a customer for recycled material. The following needs were identified in plastics recycling:

  • Aggregate streams to increase volume and economies of scale, which could include:
    • Understanding the economics of individual plastic streams, including which ones, if any, could be substitutes for one another
    • Reducing the number of plastic types used
    • Standardizing and/or tracking the additives in plastic
  • Low cost means for
    • Separating post-consumer plastic types
    • Preventing and/or removing contaminants
  • Ability to differentiate product brands and models by recyclability

Some of the potential NIST action items in NIST Special Publication 1500-204 relate to the needs above, including the action items on research on purity tolerances for post-consumer feedstocks; rapid material composition fingerprinting; publicity of product materials/composition; and AI and robotics to identify, assess, and/or disassemble products. It is important to note that the last need listed above is unique in that the ability to differentiate products by recyclability can motivate manufacturers and consumers to work toward solving sustainability challenges, resulting in a chain reaction.

Metal Recycling


Despite scrap metal having a high value, 29 % of discarded nonferrous metal and 54 % of ferrous metal ends up in a landfill. Out of 60 metal types, 34 are recycled at a rate of less than 1 % (Reck and Graedel 2012). The difficulty in separating alloys emphasizes the need to consider the end of life when designing a product. For most unrecycled metals, it is estimated that a price increase of one or two orders of magnitude might be needed to make them essentially economical. Research suggests that factors such as the concentration of metal in a product has more impact on the recycling rate than the value of metals, which emphasizes the need to consider product design regarding increased recycling. The following needs were identified:

  • Ability to differentiate product brands and models by recyclability
  • A low cost means for identifying and separating materials
  • A low cost means for reprocessing materials, which might include
    • Reducing the material variation within a product
    • New technologies and innovations in reprocessing

The NIST action items in NIST Special Publication 1500-204 regarding materials/composition; material science for the reduction/replacement of rare materials; and AI and robotics to identify, assess, and/or disassemble products relate to the needs listed above. Again, it is important to note that differentiation by recyclability stands out as it can have a domino effect where producers and consumers might be motivated to solve sustainability challenges. 

Common Barriers to Sustainability

There are some common barriers that inhibit solutions to creating a sustainable economy. Research in manufacturing and many other fields tends not to be selected/guided using measures of return such as return-on-investment or benefit-cost ratio to identify those that will have the largest impact per dollar of investment. There is also a mismatch of incentives for researchers, as they are rewarded for increasingly complex and innovative discoveries or findings published in journal articles. If superior solutions are simple or involve reiterating previous findings, the reward to the researcher is often significantly diminished. Another barrier is that there are frequently misunderstandings among the general public. People and organizations often sensationalize information, selecting statistics, data, and/or language that is often more appealing to their audience but does not necessarily represent an accurate depiction of events or reality. This can result in popularizing sustainability solutions that are suboptimal. A final barrier is that there is a tendency to value the ‘me and now’ – that is, the tendency to value short-term individualized rewards. Frequently, sustainability involves sacrificing resources for benefits to society that occur in the future, often making it difficult to gain broad support.


Created January 4, 2023