The Nordic pilot illustrates that the UNITAR model is technically feasible to apply across countries, and conceptually sound as a harmonised framework for plastic-flow statistics. However, the pilot also shows that the quality, completeness and comparability of outputs depend critically on foundational work across three fronts:
Cleaning and validating key trade and production data
Updating plastic-content assumptions where needed to increase alignment with national/Nordic conditions
Aligning institutional rules, terminology, and capacity
Taken together, these lessons highlight both the model’s promise and the concrete actions needed to realise its full value.
Model limitations reflect scope, not design flaws
The differences between the UNITAR model outputs and national plastic inventories are partly explained by the model’s limited coverage at this stage. As of this pilot, only 36% of relevant HS codes and 39% of CPC codes were included, leaving key product groups outside the scope. These differences do not indicate that the model is flawed, but are expected side effects of applying an early-stage version. However, systemic issues—such as default assumptions, input data quality, and unit mismatches—must be addressed to build confidence in the model’s results.
Value of harmonisation is clear, provided challenges are addressed
Despite its current limitations, the pilot suggests that harmonised modelling can support international comparability, policy planning, and treaty reporting. The UNITAR model offers a consistent structure for tracking plastic put-on-market and waste generation in a comparable way—provided it is supported by better data inclusion and coordinated refinement efforts, such as updating plastic content assumptions, and improving data cleaning and validation.
Data on plastic shares in waste streams are fragmented and do not match waste data
The plastic shares in certain waste streams are based on the available estimates identified by this study, using either product data or waste data. The weakness of using the product’s plastic share is that the corresponding waste stream may not have the same composition. Additionally, this study has found that obtaining reliable product data is a challenge. Estimates of plastic share that are based on waste data was identified for two of the studied streams: WEEE and textiles. A challenge in this case is to identify estimates that match waste statistics, i.e. the European Waste Codes (EWC) or equivalent to be applied. Hence, the available research largely does not coincide with these conditions.
4.1 Recommendations
The recommendations below are designed to support more robust, comparable, and policy-relevant plastic statistics across the Nordic countries. Each proposal builds on insights from this project.
Recommendation 1: Establish a Nordic coordination mechanism for plastic statistics
Insight: National efforts are fragmented, and institutional prerequisites vary
Form a Nordic reference group with regular meetings, including key experts from each country's EPA and statistics office.
Assign the group a clear mandate to validate priorities, oversee harmonisation efforts, and coordinate inputs to international processes.
Assign the group responsibility for onboarding updates from international standards, documenting choices, and resolving methodological conflicts.
Secure a dedicated budget to enable continuity, coordination, and follow-up between meetings.
Consider rotating leadership or secretariat functions to maintain engagement across countries.
Recommendation 2: Launch a joint Nordic–UNITAR project to put the method into practice
Insight: Nordic countries already have strong datasets, but lack a structured forum to jointly apply, test, and improve the UNITAR method.
Initiate a project directly involving key participants from Nordic statistical and environmental protection agencies together with UNITAR to work on applying the UNITAR model to Nordic plastic statistics.
Ensure adequate resources are made available for active participation by each country’s statistical and environmental authorities, with emphasis on:
Validating and cleaning trade and production data (as well as estimating time periods before the model and projecting into the future for accurate waste generation time series)
Ensuring comprehensive inclusion of all relevant trade and production codes in the model
Developing and harmonising plastic-content coefficients, especially in areas with national deviations or unique sectors (e.g. Norwegian offshore infrastructure)
Comparing modelled flows against existing national estimates (e.g. packaging POM, recycling rates)
Use the project to assess the coverage, sensitivity, and comparability of the model before scaling to routine implementation.
Recommendation 3: Collaborate with Producer Responsibility Organisation to explore existing and produce plastic share data
This study has identified recent textile waste data that can be applied on the textile waste stream. The source is relevant to the Nordic countries and is relatively recent (2021). It is recommended to use this data as a temporary proxy. To obtain more recent, continuous and Nordic textile data, it is recommended to form a dialogue with modern textile sorting facilities to explore how plastics in textiles can be monitored moving forward. Additionally, once Producer Responsibility Organisations are formed, they should be included in the dialogue.
The plastic share of the WEEE fraction can be estimated using data from El-kretsen, however it must be clarified how the shares for the four sub streams can be applied to the EWC coded streams.
In regard to WEEE, batteries, End of Life Vehicles and car tyres, all streams are covered by EPR legislation and thereby responsible for the generated waste and it’s handling. It is therefore recommended to increase the dialogue with the Producer Responsibility Organisations and initiate a partnership that: