“Chemical Recycling” — A Summer of Disillusionment

By Tessa Wardle

What is “chemical recycling”?

As a public health student, I have been disappointed with the concept of plastic “chemical recycling” (also called advanced recycling, chemical conversion, molecular conversion, or conversion technologies). At first I was excited to hear about a possible solution to the plastic waste crisis in the form of this seemingly miraculous technique that could give new life to difficult-to-recycle plastics and at the same time contribute to a circular economy. It all sounded too good to be true, and after a few weeks of research, I discovered that it was.

I learned that the most important form of “chemical recycling” that takes place in the United States is not recycling at all. Actual recycling recycles materials after use and returns them to the manufacturing cycle, where they are used to manufacture new products, giving these materials a new life as part of a circular economy. Processes like “chemical recycling” typically use plastic materials to generate a limited amount of energy in a one-time process that destroys them instead of giving them another material use. Pyrolysis and gasification of plastics are two processes that illustrate the fallacy of the term “chemical recycling” because instead of recycling plastic waste back into plastic products, these technologies turn plastic into fuel that will be burned, releasing greenhouse gases and toxic pollutants. The EPA is currently considering rules on pyrolysis and gasification units under the Clean Air Act, which according to my research are badly needed.

Figure 1. Overview of mechanical recycling, the primary form of recycling worldwide, and newer technologies considered “chemical recycling”. Possibilities for harmful emissions exist at several stages in each “chemical recycling process”. The most important form of “chemical recycling” that occurs in the United States transforms plastic into fuels that are incinerated. Image courtesy of Tessa Wardle.

Other forms of “chemical recycling” include solvent-based processes and chemical depolymerization. While some of these processes can result in the actual recycling of materials (plastic back to plastic), these processes are far less common than the practice of using plastic as a fuel. Solvent-based processes and depolymerization are not free from their own dangers. These processes try to separate the main plastic components from pollutants and additives. This is necessary because plastic contains a mixture of chemical additives that improve the material properties of the plastic, including texture, UV resistance, longevity and many others. Recent research has discovered thousands of novel chemical additives in plastics, many of which are classified as worrying substances.

Toxic emissions from “chemical recycling” of plastics

Given the number of chemicals of concern in plastic products, I suppose I should not have been surprised to find that “chemical recycling plants” emit toxic chemicals and dangerous air pollutants. The sources of these emissions are unknown, but may be from chemicals in plastics, chemical processing aids, chemicals produced during processing and / or combinations of all of these. I found permits for existing “chemical recycling plants” in the United States along with facility-specific data from the EPA that paint a very different picture than the industry’s claims of “few toxic emissions.” In fact, “chemical recycling facilities” are authorized to release or have registered the release of a mixture of highly toxic chemicals, including benzene, toluene, ethylbenzene, xylenes, dioxins and more. These data were of concern to me due to the association of the chemicals with cancer, nervous system damage, effects on reproduction and development, among other dangerous properties (Table). Knowing this worries me about the communities adjacent to “chemical recycling” facilities.

Toxic waste sent all over the country

The communities that are direct neighbors of these facilities are not the only ones for whom concern is relevant. According to EPA RCRA data, a “chemical recycling plant” operated by a company called Agilyx sent over 500,000 pounds of hazardous waste across the country in 2019 (Figure 2). Agilyx treats polystyrene foams using pyrolysis technologies.

Figure 2. Agilyx, a pyrolysis plant in Oregon, sends toxic waste across the country, where it is eventually incinerated. The size of the arrow corresponds approximately to the amount of waste sent. Data from the 2019 RCRA Biennial Report. Image courtesy of Tessa Wardle.

This hazardous waste is primarily benzene but includes lead, barium, cadmium, chromium, vinyl chloride and more. These chemicals are associated with health problems ranging from cancer to developmental toxicity to damage to several different organs (Table). The disposal techniques for these hazardous chemicals and heavy metals – including fuel blending and incineration (with or without energy recovery) – ultimately lead to the material being burned where it can be released into the air and affect neighboring communities. As this facility only processes polystyrene waste, it raises the question of what additional by-products can be produced from plants that process many different types of plastic.

Table. The chemicals generated by “chemical recycling” plants pose dangerous health hazards. (1) Hazards from chemicals sent off-site as hazardous waste by Agilyx and (2) Hazardous Air Pollutants (HAPs) listed in Agilyx’s Air Toxics Emission Inventory and air permits for Agilyx, Alterra Energy, Braven Environmental , Brightmark, Nexus Fuels, and PureCycle Technologies. Hazard trait data from the California Safer Consumer Products Candidate Chemicals list. Image courtesy of Tessa Wardle.

Need for real solutions

All in all, after completing a summer of research, I am strongly disillusioned with the false solution “chemical recycling.” The problem with plastic starts long before it ends up wasting the soil, which obsolete solutions like “chemical recycling” do not solve. Burning plastic for fuel is just another form of fossil fuel that harms the environment and our health. Many problems stem from the toxic nature of the plastic itself, and the right solution lies in eliminating unnecessary disposable plastics and dramatically changing our systems to center around sustainable materials that can be recycled and reused over and over again. The Break Free from Plastic Pollution Act provides a template for dealing more appropriately with the plastic waste crisis we are currently facing, and policy makers should not be fooled by the plastics industry’s green wash of “chemical recycling.”

Tessa Wardle is a master’s student focusing on Environmental Health Sciences at UC Berkeley’s School of Public Health. Her research interests include the intersection of science and politics, especially when it comes to toxic chemicals. She has previous research experience working with NGOs that focused on pesticides in California, urban oil drilling in Los Angeles, and drinking water pollution in the United States. She also holds a BA from Occidental College in Urban and Environmental Policy, where she graduated magna cum laude.

Originally published on NRDC expert blog.

Related story: EPA: Say no to burning plastic AKA “Chemical recycling”

Featured photo of Magda Ehlers from Pexels

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