Creating a Closed Loop Economy to Mitigate the Ocean Plastics Crisis

August 8, 2019
Each year, between 4.8 and 12.7 million tons of plastics make their way into the ocean.1 This is in addition to the estimated 150 million tons that currently circulate our marine environments.2 Contrary to popular belief, ocean plastics are not just a coastal problem. The Alliance to End Plastic Waste estimates that 80% of global ocean-bound plastics come from land-based sources, with the vast majority flowing from just 10 rivers.3 Although this highlights the need for better waste management, it’s wrong to blame the problem solely on this issue. To effectively mitigate the ocean plastics crisis, plastics manufacturers, waste converters, and consumers must come together to improve the life cycle of a piece of plastic from cradle to grave. In fact, researchers have found that there is an existing $120 billion addressable market in the United States and Canada for plastics and petrochemicals that may be captured in part by recovering waste plastics 4. This concept of recovering and harvesting value from used plastics is known as the circular or “closed-loop” economy. The British Plastics Foundation provides interesting insight: “we need to stop thinking of plastic as ‘waste,’ but as a renewable resource that needs to be disposed of correctly." 5

This article discusses several strategies that can contribute to an effective closed-loop economy and begin to mitigate the ocean plastics crisis. Strategies include consumer education; recycling programs to collect difficult-to-recycle plastic waste; and developing recoverable plastics, compostable plastics, and programs for plastic reuse.

Recycling Initiatives

Many players in the plastics economy erroneously believe that once they have stamped the recycle symbol on the bottom of their material, their work is done. However, plastics manufacturers and waste management entities can also play an important role in consumer education. Consumers are often unaware that plastic films on food packaging and plastic bags can ruin recycling equipment if they are placed into the same recycling stream as plastic bottles. Many also fail to realize that recyclers will not handle “dirty” plastic that is contaminated by food or other waste because the recyclers lack the cleaning methods to ensure that contamination does not make its way into the recycled plastic feed. Plastics manufacturers can benefit from conducting human factors testing to understand how consumers look at a piece of plastic waste and what they do with it. Do consumers readily and easily see the recycle symbol? Do they understand which plastics are recyclable and which are not? Do they know what steps they can take to prepare waste for recycling? By enhancing recycling throughput, we can reduce the amount of plastic waste that can pollute our oceans, while gaining value in the form of recycled plastic feedstock. In other words, when plastics manufacturers and waste management industries better understand how consumers are currently treating their plastic waste and what type of additional education may be needed to ensure more effective recycling, plastic waste can become a beneficial resource.

Plastics manufacturers can also partner with waste converters to identify methods for improving the collection and treatment of difficult-to-recycle plastic waste, including plastic films and bags, dirty plastics, and medical plastics. For sterility and biohazard purposes, nearly all medical plastics begin as virgin material and are disposed of via incineration or landfills. One environmentally friendly alternative is to develop programs that recover, clean, and sterilize biohazardous medical plastics and then reintroduce those materials as recycled feedstock.6

Over time, savvy plastics manufacturers and waste converters are likely to develop new protocols to collect difficult-to-recycle plastic waste, as well as buy-back programs and incentives to enhance results.

Development of Recoverable and Compostable Plastics

Some plastics manufacturers are exploring the development of plastics that purposefully break down into monomers that can then be resynthesized into new plastic (i.e., “recoverable” plastics). Although scientists have begun to explore work in this area7, further technological advancements are needed to identify what is feasible. In parallel, innovators will need to consider how best to incorporate recoverable plastics into reliable products and practical industrial processes.

The plastics industry can also consider compostable plastics for many applications, including single-use products. This approach involves the engineering of plastics that break down into safe byproducts under appropriate conditions. Appropriately qualified compostable plastics would not persist in the environment in the same manner as traditional plastics; consequently, they might play a role in curbing the accumulation of plastics in the ocean.

Repurposing and Reusing Plastic Waste

Finally, all stakeholders in the plastics life cycle can do more with transforming plastics into fuel, energy, or other raw materials. Plastics have the ability to be transformed into hydrogen8,9, diesel, crude oil, or sulfur-based fuels, as well as other energy sources. This technique, which businesses and other entities are currently capitalizing on, provides a new purpose for plastics that would otherwise pollute our environment. Our team at Exponent recently partnered with a large global company to conduct a market and technical analysis for the reuse of textile and rubber scraps that typically ends up in landfills (e.g., using rubber scraps as playground flooring). We identified several niche applications that would enable the client to drive the reuse of these scraps and recover cost. These types of scrap materials are not traditionally recyclable or compostable; however, by repurposing these materials they can provide added value in the closed-loop economy.

Potential Challenges

It is important to note challenges to the above strategies. “Plastic” is a general term that incorporates a broad range of families and grades of polymers and specific additives, with a vast range of functional properties and uses. Understanding the complexity of the plastic landscape is necessary for implementing sustainable efforts. For example, because of the wide range of sources for plastics, creating and processing reliable, consistent plastic feedstock from recycled content is difficult. Here, questions related to reliable sourcing, chemical purity, and material consistency are focal points in the plastics industry. In addition, there are many ways to recycle or reuse plastics which will result in different functional consequences. For example, plastics have the potential to lose their physical properties over time due to polymer degradation, particularly as a result of continued thermal or mechanical recycling treatments. This means that plastics cannot necessarily be continuously recycled forever. The process of managing contamination in recycled feedstock is also difficult and not yet well understood. Sampling, testing, and analyzing quality control procedures are essential for managing degradation byproducts and other contaminants that could be present in recycled feedstock.

Finally, the scientific community recognizes that compostable, recoverable, or repurposed plastics require a significant R&D effort, which will take many years to reach widespread implementation. Global cooperation among governments, food contact and environmental regulators, not-for-profit entities, nongovernmental organizations, and consumers must complement the efforts of plastics manufacturers and waste converters to fully close the loop and mitigate the ocean plastics crisis.

How Exponent Can Help

Exponent’s multidisciplinary team of environmental scientists, toxicologists, materials engineers, chemists, physicians, and regulatory experts can partner with plastics manufacturers and plastics converters to provide many services, including but not limited to:

  • Assisting plastics manufacturers or converters with material selection, characterization, qualification, and process enhancement for the use of recycled, recoverable, or compostable plastic feedstock in place of virgin, nonbiodegradable plastics.

  • Providing guidance related to applicable standards for non-virgin plastic feedstock or plastic products (e.g., ASTM, UL, ISO, etc.).

  • Identifying niche reuse applications for scrap plastic materials or difficult-to-recycle plastic waste.

  • Identifying risks and trends for plastics in the environment.

  • Identifying contamination or chemical exposure risks in recycled, recoverable, compostable, or reused plastic feedstock or products in the context of human health (e.g., California’s Proposition 65 and REACH).

  • Providing guidance on human factors–based concepts to improve waste recovery, recycling, or buy-back efforts at the manufacturer, consumer, or waste-converter level.


1 Jambeck, JR, et al. 2015. Plastic waste inputs from land into the ocean. Science 347. 6223:768–771.