Monitoring of mixed plastic collections

How it all began

Mixed domestic plastic waste now makes up a large proportion of municipal waste in terms of volume. When recycled, it can make a key contribution to the circular economy, conserving resources and cutting CO2 emissions. To take this fact and also the population’s need for separate collection and release of mixed domestic plastics into account, offers for the collection and recycling of plastics have been set up in various regions of Switzerland.

In 2018, three of the largest collection systems collaborated with the Association of Swiss Plastic Recyclers (VSPR) to develop a plastic charter¹ that defines the essential requirements for the collection and recycling of plastic waste from Swiss households. Empa developed a monitoring system in 2019 based on the charter and environmental regulations. It consists of verifiable requirements², an inspection protocol, a manual³ and an Excel-based data collection tool. The model was the Swico and SENS inspection system, which Empa was also involved in setting up and further developing over the years. The idea was that collection systems could voluntarily subject themselves to monitoring by participating in a licensing system, with the aim of ensuring credible and transparent monitoring of plastic collection as an industry solution.

Pilot certification

An independent inspection body, which audits the system operators and their treatment partners in terms of requirement compliance, as well as assessing their conformity, was established with the licensing system. dss+ (then still known as Sofies-Emac AG) won the bid to set up the inspection body and perform the first pilot audits. The main task of the inspection body even today is still to ensure that the collected plastics are sorted, processed and recycled according to the state of the art and are returned to the cycle as high-quality secondary plastics. It also monitors to ensure that non-recyclable plastic waste is thermally recycled as substitute fuel in cement plants or waste incineration plants rather than ending up in illegal landfills or even in the ocean.

During the 2020 pilot year, the systems sammelsack.ch, kunststoffsammelsack.ch and KUH-Bag (as a project of three special-purpose associations) and their handling partners were audited and certified. In the course of data collection for the audits, harmonised key figures were gathered for the first time across the various collection systems. The aim was to provide clear and transparent information about the current whereabouts of the mixed plastic waste collected from households in Switzerland through an annual monitoring report.

Similarities and differences

In contrast to the Swico and SENS inspection system, where the auditors monitor the recyclers for the systems, in the VSPR monitoring system, the systems themselves are monitored and licensed on their behalf. Domestic plastics are classified as municipal waste and are therefore subject to the cantons’ disposal monopoly. The monitoring ensures that all licensed systems comply with the legal requirements and the same industry standard for collection, processing and documentation. The initial processors, some of whom only sort the plastic waste while others also process it directly into regranulate, are monitored in the same way as the Swico and SENS recycler audits. Where necessary, secondary collector checks are also taking place at an increasing rate.

Mixed domestic plastic waste is significantly less heterogeneous than waste electrical and electronic equipment (WEEE), and hardly contains any pollutants (Figures 1 and 2). Missorted waste containing harmful substances (e.g. WEEE) or unwanted plastics (e.g. PVC) can be easily removed during the sorting and recycling processes. For this reason, the VSPR requirements are significantly leaner than those set out in the CENELEC standard (EN 50625).

^{1 https://www.plasticrecycler.ch/wp-content/uploads/2019/11/Kunststoff-Charta-Schweiz_2018_VersAug2019.pdf
2 https://www.plasticrecycler.ch/wp-content/uploads/2022/01/Anforderungen_Kunststoffsammlungen_2022.pdf
3  https://www.plasticrecycler.ch/wp-content/uploads/2022/01/Monitoringhandbuch_2022_komplett.pdf}

The monitoring system is gaining momentum

The VSPR celebrated its tenth anniversary in 2023. Since the pilot certification, four additional systems have been added and successfully licensed⁴. This also includes the EPS-Recycling Schweiz system, which collects and recycles EPS (expanded polystyrene or Styrofoam) and XPS (extruded polystyrene) from households, as well as from construction and commercial areas throughout Switzerland.

The collection volumes of mixed plastic waste have grown from around 5,300 tonnes in 2019 to almost 9,500 tonnes in 2022 (Figure 3). Around 900 municipalities in 23 cantons across Switzerland are connected to a collection system. This means that over 4.8 million residents now have the opportunity to collect and recycle their plastics. Of the collected and processed amount, around 53% is recycled, while the rest is thermally recycled in cement plants or waste incineration plants⁵.

^{4 https://www.plasticrecycler.ch/label/
5 https://www.plasticrecycler.ch/wp-content/uploads/2023/07/Monitoringbericht_VSPR_2022_DE.pdf}

Despite these successes, there is still much work to do. The collection rate of the licensed systems, based on the estimated total volume of plastic waste from households in Switzerland, was around 5% in 2022. So there is still massive, untapped potential for increasing the collection rate. The VSPR sets strict standards for the industrial return rate, i.e. the ratio of the recycled material volume in relation to the amount brought in for processing. It is calling for the rate to be increased to 55% by 2025 and to 70% in the long term. In addition, as of this year, the residual materials from the processing of plastic waste that cannot be recycled must be returned to Switzerland for energy recovery. This makes the transparent tracing of these material flows much easier.

Conclusion

The certification of mixed plastic collections and their reporting is new territory in Switzerland. The successfully established voluntary monitoring system shows that the tools developed for a sustainable and transparent measurement culture in the Swiss plastics landscape work well and create trust and certainty among authorities and the population.