Understanding Plastic: The Hidden Complexities of Recycling and Strategies for a Sustainable Future

Photo by Antoine GIRET 

Recycling plastic is a complex process, and while it's not entirely impossible, many challenges make it difficult. Here are some of the reasons:

Types of Plastic: Many different types of plastics are denoted by the numbers 1 through 7 inside the triangular recycling symbol. Each type of plastic has to be recycled differently. This means that plastics must be sorted before recycling, which can be labour-intensive and costly.

Seven major types of plastics exist, each designated by a Resin Identification Code (RIC). These are

#1 PET (Polyethylene Terephthalate): Frequently used in soft drinks and water bottles. PET is relatively easy to recycle and often turns into polyester for the fibre industry.

#2 HDPE (High-Density Polyethylene): Found in milk jugs and detergent bottles. Like PET, it is widely recycled into new bottles or plastic lumber.

#3 PVC (Polyvinyl Chloride): PVC is difficult to recycle due to its high chlorine content and harmful dioxins released throughout its life cycle. It is often used for pipes, artificial leather upholstery or window frames. Its use is completely banned in many countries like Canada, Spain, South Korea, and the Czech Republic, and in some countries, it is prohibited in the production of children's toys and the packaging of food products. Germany has banned the disposal of PVC in landfills since 2005, and strict controls on PVC in 274 regions have been put into effect by local governments. On May 8, 2023, the European Union (EU) issued Regulation (EU) 2023/923 to revise the restriction of lead and its compounds falling under entry 63 to Annex XVII of Regulation (EC) No. 1907/2006 'Registration, Evaluation, Authorization and Restriction of Chemicals (entry 63 to Annex XVII of REACH).

PVC is the most environmentally damaging plastic there is. As it says in the name, Polyvinyl chloride contains chlorine, which has been linked to many toxic environmental problems, including destroying the ozone layer. Chlorine toxins build in the air and flow through the water and the food chain, leading to humans unintentionally ingesting them. When humans ingest the toxins, it can lead to several health problems, including infertility issues, hormone disruption, cancer, and much more. PVC also creates dioxins, which are very toxic to the environment and can be ingested by humans. Independent laboratories and environmental organisations have reported that dioxins are the most toxic chemical compound in the world and are extremely dangerous to humans and the environment. With environmental and health concerns, it’s no wonder why countries and companies are looking to leave PVC.

#4 LDPE (Low-Density Polyethylene): Recycling of LDPE in plastic bags and film wraps is increasing, but not widespread enough due to its low economic value.

#5 PP (Polypropylene): Often used in straws, bottle caps, or food containers. PP recycling is growing but still needs to be more prevalent than PET or HDPE.

#6 PS (Polystyrene): Commonly known as Styrofoam, PS is rarely recycled due to the cost and environmental impact of the process.

#7 Other (BPA, Polycarbonate, and LEXAN): A catch-all category for other plastics, including bioplastics. These are rarely recycled due to the mixture of different plastic types.

Each type of plastic requires a different recycling process, which adds complexity and cost to the recycling stream.

Contamination: Plastics must be clean to be recycled appropriately. Food residues or other types of contamination can interfere with the recycling process. Removing these contaminants can be costly and complex. Contamination occurs when non-recyclable materials or food waste mix with recyclable plastics. This can significantly disrupt the recycling process, discarding the entire batch. In single-stream recycling programmes, where all recyclables are collected, the risk of contamination is high, and the recycling rate is often below 10% as plastics are often mixed or are not clean for recycling. Consumer education on proper recycling is a constant challenge, and most plastics are indistinguishable in quality to the consumer, while recycling rules often vary by the local authority.

Quality Degradation: Unlike materials such as glass or metal, the quality of plastic deteriorates each time it is recycled. The polymer chains that make up the plastic shorten during recycling, which causes the physical properties of the recycled plastic to deteriorate. This means the plastic can only be recycled a few times before it becomes unusable. PP (Propylene), one of the most widely used plastics, exceeds the limit where it can maintain its physical properties after the third recycling and becomes unusable in line with its qualities. For example, PET plastic is often recycled into textiles, carpets, or plastic timber. These products can no longer be recycled again. As a result, plastic materials are eventually sent to landfill or incineration.

Non-recyclable Plastic Items: Not all plastic items are recyclable. Items like plastic bags, plastic wrap, and Styrofoam often cannot be recycled through curbside recycling programs and require special processing facilities. Plastic items like plastic bags, film wraps, and Styrofoam are challenging to recycle and often must be addressed at recycling facilities. They can get tangled in machinery, leading to costly shutdowns and repairs. While there are specialised facilities that can handle these materials, more widespread access is needed to ensure that these items often end up in landfill or the environment.

Economic Factors: Recycling plastic costs more than producing new virgin plastic. This cost can be recovered only in the case of high-cost technical plastics that can be recycled. This economic reality and fluctuating oil prices (since plastic is derived from oil) have a chilling effect on recycling efforts. The low cost of the oil from which virgin plastic is derived often makes it cheaper to produce new plastic than to recycle existing plastic. This economic reality weakens the viability of plastic recycling. Furthermore, the market for recycled plastics depends on the demand of producers, which can fluctuate depending on various factors such as oil prices, the quality of the recycled material and regulations. One of the biggest challenges for producers is the quality of the content of recycled plastic (additives, colourants, etc., used to achieve specific physical properties). Manufacturers cannot rely on recycled plastics when set or regulated quality standards and physical properties must be strictly adhered to.

Lack of Infrastructure: Not all communities or countries have the necessary infrastructure for plastics recycling (facilities for sorting, cleaning, and reprocessing plastic waste, etc.), and consumers have almost no knowledge of the issue. The infrastructure for recycling plastics needs to be more consistent globally and even within individual countries. This includes facilities to process recyclable materials and collection and sorting systems. Even if consumers are keen to recycle, their efforts are wasted if local facilities cannot adequately process the material. Some countries have a policy of exporting their existing waste to other countries to keep it out of their geography. In contrast, the geography through which microplastics enter the environment does not matter, nor can it save the sending country from the consequences of polluting the planet.

To address these challenges, efforts are being made to improve recycling technologies, design better plastic packaging, and shift towards a circular economy where waste is minimised. However, it's also critical to reduce plastic consumption, reuse where possible, and choose alternatives to plastic where feasible.

In addition to these problems, the linear economy model of "take-make-dispose" is fundamentally at odds with plastic recycling. For recycling to be part of a sustainable solution, there is a need to move to a circular economy/consumption model where waste is minimised and materials are kept in use for as long as possible.

While plastic recycling has a vital role in waste management, there are more practical options. Reduction in plastic use, redesign of plastic products, switching to alternative materials, and improvements in recycling infrastructure and technology are all critical components of addressing the plastic waste crisis.