Norwaste, with funding from the Retail Environmental Fund and Grønt Punkt Norway, has investigated product residues in plastic packaging from households. Plastic packaging from households faces a challenge in that it contains more contamination than the goal set by Plastretur. Grønt Punkt Norway has investigated and found that collected plastic packaging from municipalities contains more than 11 percent contaminants, while the goal is 5 percent. The most common forms of contamination included are other plastic products (non-packaging) and other waste (residual waste) that are not plastic or food, as well as product residues in the packaging.
In this analysis, it is the product residues that have been examined more closely. Two methods were used to assess product residues: original product quantity and based on the size of clean packaging. The average percentage of product residue from all similar products was used.
Looking at product residue per gram of product, the content of product residue was lower in source-separated plastic packaging than in centrally sorted plastic packaging. An exception was soaps in HDPE. The content of product residue was significantly higher in products from unsorted residual waste from municipal waste companies. Toothpaste, jam, cream, yogurt containers, and chocolate spreads are products with the greatest difference in product residue between centrally sorted and source-separated plastic packaging. Dressing and liquid butter are relatively similar, while soaps have less product residue in centrally sorted than in source-separated plastic. A common characteristic of these products is that they are more liquid, and any product residue may have leaked out onto other waste in the residual waste. It is noted that there were different numbers of samples for the various products.

- These are very interesting findings, and there is a need for more knowledge on how we can make plastic packaging even cleaner.
Johannes Daae, Development Manager at Grønt Punkt Norway Tweet
Can design affect product residues in plastic packaging?
The design of packaging can have a significant impact on whether the packaging is recycled or not, both in terms of user-friendliness for the consumer related to understanding the material and cleaning the packaging, as well as how easy it is to sort it in the waste system. For example, design elements such as bottle openings, such as how easy the cap is to remove, can be crucial for using up the product and getting the packaging clean. Another example is foil packaging, which usually needs to be cut open by the consumer to be completely clean. Packaging that can be easily opened can also be more easily refilled. Another possible trend is the use of transparent packaging, such as PET bottles for soap, which makes it easier for consumers to see if there are any product residues left. In the project, the relationship between how much product the packaging could contain with as little packaging as possible was also investigated. Here, examples emerged that design can play a role, including in the design and choice of polymer for the cap. Heavy or large caps result in less utilization of the packaging per gram of product.
The report also highlights how labeling on packaging can help consumers sort correctly. Much of the packaging has transitioned to the new labeling scheme, however, not all packaging adheres to the regulatory system of the scheme. For instance, there were several instances of incorrect background colour on the symbol for plastic packaging (see the image at the top right). Additionally, it is noted that the secondary labelling (black colour with the plastic symbol, see image at the bottom right) can be confusing, as the black colour at first glance may also be misinterpreted as residual waste.
- These are important findings that all manufacturers should take note of regarding design for recycling. We know that people find it challenging to sort correctly, so clear and accurate labeling is crucial to increase
Cecilie Lind, Managing Director of the Retailers' Environmental Fund. Tweet

More PE film is sorted out by central sorting than in source-separated plastic.
The project also examined the distribution of various packaging forms and polymer types. Adjusted for sorted tonnage from the central sorting facility, it is estimated that PE film constitutes 56 percent of the plastic packaging sorted from central sorting. This is significantly higher than what was observed in source-separated plastic, which was 26 percent. In this analysis, bags used as waste bags were not categorized as plastic packaging. If waste bags and other non-packaging plastics are included, PE film and waste bags together account for a total of 60 percent in centrally sorted and 30 percent in source-separated plastic. In central sorting, waste bags for residual waste can also be sorted out, which may explain some of the difference from source-separated plastic. The distribution of PP rigid plastic, HDPE bottles (non-beverage), PET beverage bottles, and other HDPE is approximately equal. In source-separated plastic, a larger quantity of PET trays with film and PET trays without film was found compared to centrally sorted plastic delivered for material recycling. One reason for this could be that some PET is sorted into the mixed plastic fraction, the remaining fraction of plastic left after the four other plastic fractions are sorted out. 25 percent of the plastic packaging in mixed plastic consisted of PET trays with film.

The project has contributed to providing an overarching insight into the distribution of polymers in packaging and product residues in selected products. The report concludes that further analysis is needed to substantiate the findings in this report.
The entire report can be downloaded here (only in Norwegian), or from the Retailers' Environmental Funds webpage.