Subtopic 3: Types of plastic – which are safe and which to avoid?

Through recycling it is possible to convert waste into a base material, so there is no longer a need for a third party to manage this type of waste. In addition, the amount of source material needed to carry out production decreases.

Additionally, if plastic waste is collected separately at source, it is possible to reduce the energy required for its recycling.

In order to recycle these plastics, the first thing to do is separate them. Not all plastics are the same. There are different types, each with different properties and uses. Depending on the type, they can also be recycled differently. However, products often consist of a mixture of different types of plastics.

Understanding the different types of plastics and their recycling codes will help you make informed decisions about the proper recycling of plastic items.

One common type of plastic is polyethylene terephthalate (PET), which is used in plastic bottles and food containers. PET is usually labeled with the recycling code “01 PET” and is widely accepted for recycling. However, PET used in plastic bottles secretes the liquid acetaldehyde which is harmful to humans.

Another type is polyethylene (PE), which is used in milk jugs, detergent bottles, and plastic bags. PE is labeled with the recycling code 04 PE-LD (Low-Density Polyethylene) or 02 PE-HD (High-density Polyethylene) and is often used for disposable packaging.

Other types of plastics include polyvinyl chloride (03 PVC), which is very difficult to recycle, polypropylene (05 PP) and polystyrene (06 PS) (Global2000).

Figure 2. Plastic recycling codes (Global2000).

Figure 3. The plastic roundabout (Plastic Atlas, 2020)

These plastics have varying recycling codes and may or may not be widely accepted for recycling depending on local recycling programs. It is important to check with your local recycling facilities to understand which types of plastics are accepted in your area to promote responsible plastic recycling and reduce plastic waste pollution.

It must be taken into account that, usually, the quality of reused plastics is not the same as that of the original material. This is due to the fact that plastics gradually suffer thermal degradation due to injection and extrusion processes, where temperatures rise considerably. Therefore, it is convenient to incorporate this reused plastic mixed with original plastic, to achieve the same or very similar properties to the original parts. Depending on the type of plastic, the percentage of reused material may be higher or lower.

There are several methods for recycling or regaining energy from plastic waste. Mechanical recycling is a common method where plastic waste is collected, sorted, cleaned, and then melted down to be used as raw material for manufacturing new plastic products. Another approach is chemical recycling, which involves breaking down plastic waste into its chemical components to create new plastics or other materials. This method has the potential to recycle a wider range of plastics, including those that are difficult to recycle mechanically, such as mixed plastics or multilayer packaging (Barrett, 2020).

Energy recovery is also an option, where plastic waste is burned in waste-to-energy facilities to generate electricity or heat. However, it is important to note that this method should be used as a last resort after all other recycling options, as it results in the release of greenhouse gases. Additionally, methods such as upcycling, where plastic waste is transformed into new products, and reducing plastic consumption through waste reduction strategies are gaining popularity as sustainable ways to manage plastic waste (WU, 2021).

However, not all plastic is recyclable – or is recycled; at some point, recycling comes to an end.

Closed-loop recycling is possible with some types of plastic, especially PET bottles, but it is not the rule. Recycling is often “downcycling”: For example, disposable PET bottles are not turned into new bottles, but into fibers for the textile industry, which cannot be recycled again. The plastic types, PE and PP, i.e. the polyolefins used in the majority of cases, lose quality with every treatment.

For recycling to be as effective as possible, pure, and uncontaminated plastic is needed. A detergent bottle that is colored black or a shampoo bottle that is completely enclosed in a thin printed film can only be recycled with difficulty or not at all. Therefore, it is important to consider recyclability as early as the design stage (source).

Efforts to increase plastic recycling rates require a new approach that combines scientific research, technological advancements, and behavioral changes as a society as well as individuals.

In Europe, significant progress has been made in recent years, with an estimated 46% of plastic packaging waste being recycled in 2020 (Plastics Europe, 2022).  However, challenges continue to exist, as a large part of plastic waste is still burned, landfilled, or ends up in the environment, leading to pollution and environmental degradation. New kinds of “green plastic” that are biodegradable seem promising, however, there is a need for further research and development to reduce the time they need to degrade (European Parliament, 2023).

Additionally, promoting awareness and understanding plastic recycling among adolescents and the wider population, along with policy decisions, such as producer responsibility and circular economy strategies, can create a better environment for increasing the amount of plastic that is recycled in Europe.

As awareness about the problems of plastic usage grows in the general public and more and more people refrain from using it altogether, businesses and corporations acknowledge the need to adapt their marketing strategies for products containing plastic. According to a study by the Federation of German Consumer Organisations, the majority of people living in Germany consider the reduction of plastic packaging waste as “very important” (Verbraucherzentrale Bundesverband, 2018).

However, as companies observe this public trend, they take advantage of it by selling plastic products advertised as being “recycled” or made from “ocean plastic”. In these cases, the products often lack labels that indicate how much plastic has been recycled.

The term “ocean plastic” (or ocean-bound plastic, OBP) refers to products containing recycled plastic that has been fished out of the ocean. Customers are led to believe that the plastic originates directly from the ocean. Yet, plastic waste swimming out in the open ocean often cannot be recycled due to its decayed condition. Instead, most of the “ocean plastic” is gathered from coasts and beaches, a fact that companies rarely mention in their advertising. Furthermore, most legislations lack an exact definition of the term “ocean plastic”, which means manufacturers are free to label any product as “recycled from the ocean” even though only parts of it have been recycled (Schulz, 2020).

Despite the apparent greenwashing surrounding “ocean plastic”, products with this label may still be a better choice than “conventional plastics” (Schulz, 2020).