4. Conclusions and recommendations

This report analysed several potential sources to obtain information about the use of secondary materials in the Netherlands. In the following the main conclusions and recommendations for follow-up research are presented.

It was found that the Transport Statistics currently lack the level of detail needed to determine where secondary materials are used. The exploration of different CBS company surveys identified the Production Statistics survey as the most suitable survey to collect data on the use of secondary materials.

The aims of the interviews with industry associations were to determine where in the value chain information on the use of secondary materials is available and to validate assumptions made in the MFM. These interviews highlighted the importance of a common language as currently many different definitions of secondary materials are used. Thus, simply asking companies for their use of secondary materials is likely to result in inconsistent data. The interviews further revealed the availability of various data sources which could be employed in the context of the MFM, however, also these are likely to have some consistency issues. The industry associations seemed generally willing to share data as long as it does not relate to specific businesses. However, it is not desirable to depend on external organisations to compile official CBS statistics. In order to ensure quality and consistency over time it is preferred that Statistics Netherlands uses its own data as much as possible.

Based on our findings we recommend starting a process to make changes to the Production Statistics (PS) questionnaire. As earlier explained, respondents who have responded in previous years are given a list of CPA codes to choose from which are determined by their choices in previous years. In order to make it easier for respondents to select secondary CPA codes, the secondary codes corresponding to the previously chosen primary code can also be provided as an option. Thus, if the respondent selects primary steel in year t, the respondent will be given the choice to select from both primary and secondary steel in year t+1. To implement this, a table linking secondary CPA codes with the corresponding primary CPA codes is needed, the work flow needs to be described and tested (e.g., that the secondary material codes are added based on the previously selected primary material codes but not vice versa). It is also important to determine how much longer the lists of CPA codes displayed can potentially become for companies. Changes to the PS questionnaires need to be undertaken carefully and the potential consequences of the change need to be fully understood beforehand. This seems to be a promising next step as it can be implemented easily and the feasibility of this endeavour was confirmed by the CBS colleagues governing this survey. A discussion with Dutch policy makers determined this option as the preferred one to pursue in 2022. In this discussion several industries were identified that are interesting for an initial implementation:

• Plastics: the actual reuse of recycled plastics is an important topic in policy, however, there might be overlap with the Plastic Pact and coordination is needed.
• Textile and clothing: this sector is also of interest for policy makers, it needs to be considered that there is also a lot of export of used clothing and thus less recycling in the Netherlands.
• Construction and demolition waste: interesting sector as these are very large waste streams. These materials are very heavy and therefore probably reused in the Netherlands, however, data collection could be challenging if the same company recycles and reuses the materials.
• Chemical industry: interesting because chemical waste seems to be used in more industries than expected as was found during closer inspection of the CBS production statistics data.

While we do not recommend using data from industry associations for monitoring, this data could be used for validation purposes. We thus recommend to analyse existing and forthcoming data sets of industry associations to further evaluate the MFM and to ensure that the assumptions used are and remain appropriate as the economy becomes more circular. This data can also be used to validate new data obtained from an improved PS survey.

Once the data from a modified PS has been obtained validated then the data should be used to make targeted improvements to the MFM. The analysis based on the current PS shows two areas which should be focused upon in the first instance, namely:

• The use of chemical waste in the basic chemicals industry, the printing industry and the treating, coating and machining of metals industry.
• The use of secondary metals in the construction materials and metal packing materials industries.

Finally, in order to improve the level of detail and quality of data on the use of secondary materials in the long-term it is recommended to explore the potential of existing Statistics Netherlands software which retrieves data directly from business’s administration systems. With this software data on the use of secondary materials could be obtained directly from companies, ensuring reliable data without increasing survey pressure. This research includes further exploring whether companies and which companies have the relevant data and are willing to share them.