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Carbon nanotubes (CNTs) are a family of thin, cylindrical carbon nanostructures. The applications and toxicity of CNTs are still being researched, but they may be used to fabricate strong, lightweight composite materials, high-performance electronics, and energy storage devices. In 2019, the Swedish nonprofit ChemSec added CNTs to its Substitute It Now (SIN) List due to the material’s carcinogenicity, persistence, and possible reproductive toxicity. ChemSec states that the SIN List applies the criteria of the European Union’s REACH legislation to identify chemicals that should be removed as soon as possible from articles, products, and manufacturing processes.

In 2024, six academics representing the fields of pharmacology, biophysics, and public policy authored an article in Nature Nanotechnology (PDF) that responded to proposals to restrict CNTs by ChemSec and other organizations. According to the authors, increased use of CNTs and concerns about their health and environmental impacts “highlight the unmet need for a standardized, science-based approach to assess their risks and exposures from a life cycle perspective and to provide accurate information on these risks to policymakers.”

The authors also addressed the potential role of CNTs in decarbonization and sustainability strategies, noting that CNTs may require less energy and materials and have fewer environmental and social consequences than alternatives. “Of course, any movement along this pathway must give due consideration to ensuring social equity, human health, and environmental safety throughout the life cycle,” the authors stated.

Rachel Meidl, LPD, CHMM, the deputy director of the Center for Energy Studies at Rice University’s Baker Institute and one of the co-authors of the 2024 article, stressed that effective sustainability strategies require a systems-based, life-cycle-oriented approach. In an email to SynergistNOW staff, she explained that narratives portraying sustainability as a simple compliance checklist are overly simplistic. “Without a systems perspective,” she wrote, “product stewardship and sustainability efforts risk becoming reactive, short-sighted, and susceptible to promoting surface-level solutions that shift burdens rather than consider holistic interactions.”

What Is a “Systems-Based” Approach?

“Sustainability in its truest form is a systems-level approach that considers the wide array of environmental, social, and economic factors and assesses how they interact,” Meidl wrote in an article for Forbes in 2021. That is, for a material, process, or product to be truly sustainable, product stewards must consider its impact across its entire life cycle, rather than focusing on a subset of issues. The proposal to restrict CNTs demonstrates the importance of developing this systems-based perspective, although the organizations in question were more concerned with potential health risks than environmental consequences. Instead, product stewards should evaluate the full range of causes and effects related to their products and processes, including but not limited to geopolitical circumstances, impacts on vulnerable communities, and laws relating to health, safety, labor, and the environment in jurisdictions where materials are extracted, processed, or disposed of. Only by taking this broad approach can product stewards ensure that their organizations’ products and services are truly sustainable, rather than simply transferring negative impacts to regions where they are less visible.

Meidl also stressed that sustainability efforts should not be treated as checklists, prescriptive frameworks, or static sets of metrics. A systems-based approach to sustainability is more nuanced, holistic, and realistic. “[S]ustainability is not about eliminating impacts or achieving perfection,” she wrote to SynergistNOW staff, “but about making deliberate, pragmatic choices that minimize and balance risks, where the benefits and burdens of progress are shared rather than shifted, recognizing that trade-offs are inevitable and reflect the realities of dynamic global systems.”

“Sustainability is a feature of a system in its entirety, not a singular focus on any individual part,” Meidl wrote for Forbes. “It embodies how the parts interrelate to enable effective overall outcomes.”

Life Cycle Assessments

Life cycle assessments (LCAs) are a significant part of a systems-based approach to sustainability. Writing for the Baker Institute in 2021, Meidl described LCAs as “an analysis technique to evaluate the full spectrum of impacts associated with every stage of a product, service, or activity, from cradle to grave.” LCAs may consider raw material extraction, materials processing, and the manufacture, distribution, use, transportation, and disposal of products. Understanding the environmental, social, and governance impacts of products throughout their life cycles helps decision-makers understand and measure sustainability and develop accurate public policy.

“LCAs are rigorous scientific tools for understanding the environmental impacts of products, processes, and services,” Meidl wrote to SynergistNOW staff, “but they are only as useful as the scope, boundaries, data quality, and metrics they employ.” In her view, LCAs are often “narrowly constructed” in that they focus mainly on the climate and emissions impacts of a portion of the supply chain, rather than more extensive environmental, social, and economic factors. “This limited view distorts sustainability profiles, misguides public perception, and contributes to misguided policies and investments,” she wrote.

“As LCAs become mainstream in business strategies, ESG reporting, and policy frameworks,” Meidl continued, “it is vital to expand their scope and contextualize their findings to reflect full life cycle realities.”

Practical Implications

Adopting a systems-based perspective on sustainability has practical implications for product stewards and their employers. A more nuanced approach helps product stewards navigate complicated regulatory and market landscapes. One area in which product stewards may find themselves making different decisions is in materials selection. “Instead of choosing a material solely for its low carbon footprint,” Meidl wrote to SynergistNOW staff, “a steward might also evaluate recyclability, human health implications, geopolitical sourcing risks, and regional waste infrastructure—factors often missed in narrow LCAs or narrow applications of sustainability.”

Broadening the scope of LCAs may help product stewards vet suppliers and procure more sustainable materials. “With expanded life cycle insights,” Meidl continued, “product stewards can identify upstream and potential downstream vulnerabilities—such as mining impacts or human rights concerns—and work with supply chain partners to address them proactively.”

A systems-based approach also helps organizations better substantiate their claims to sustainability because their sustainability metrics will reflect conditions in the real world, rather than selective or simplified data points, Meidl explained. With global organizations such as the International Sustainability Standards Board and jurisdictions from California to the European Union issuing sustainability disclosure rules, “product stewards play a vital role in ensuring that sustainability narratives are credible, balanced, and rooted in defensible data,” Meidl wrote.

She stressed that product stewards must engage with the methodologies, metrics, and narratives that shape sustainability decisions. Sustainability narratives “are essential for building trust, aligning stakeholders, and reinforcing the authenticity of sustainability efforts,” Meidl wrote to SynergistNOW staff. These narratives may communicate qualitative aspects of sustainability, such as community well-being, cultural relevance, ethical trade-offs, and long-term resilience. They may also connect high-quality data with real-world scenarios and translate results into language that resonates with regulators, investors, employees, and customers.

Reframing Sustainability

A systems-based, life-cycle-oriented approach will be the focus of Meidl’s opening keynote session at PSX 2025, “Reframing Sustainability: A Systems Perspective on a Sustainable and Circular Economy.” According to Meidl, her keynote “will underscore that sustainability is complex and dynamic—not a fixed destination.”

“By deepening their understanding of systems thinking, trade-offs, and the inherent uncertainties in sustainability frameworks,” she wrote, product stewards "will be better positioned to lead cross-functional efforts, communicate more transparently, and build strategies that are not only credible but also resilient, equitable, and grounded in reality.”

PSX 2025, the Product Stewardship Society’s annual conference, will be held Sept. 16–19 at the Westin Gallery in Houston, Texas. For more information or to register, visit www.psx.org.

Resources:

Baker Institute for Public Policy: “Sustainability and Life Cycle Assessments: Occam’s Razor Does Not Apply” (Feb. 20, 2025).

Baker Institute for Public Policy: “Waste Management and the Energy Transition: The Path to Sustainability and a Circular Economy” (Feb. 19, 2021).

Forbes: “A Circular Economy Does Not Necessarily Translate To Sustainability” (Aug. 3, 2021).

Nature Nanotechnology: “Banning Carbon Nanotubes Would Be Scientifically Unjustified and Damaging to Innovation” (March 2020).

Nature Reviews Materials: “Human and Environmental Safety of Carbon Nanotubes Across Their Life Cycle” (PDF, January 2024).

*Original Source: SyngeristNOW