The figures describe all (primary) energy and water needed to make the materials and it describes the greenhouse gases released during material production. The material production includes the extraction of the raw materials, transport to the factory and production in the factory (i.e. cradle-to-factory-gate). The figures do not include transport from factory to the next production location and distribution to consumers, nor do they include the steps of use, recycling or end-of-life. It only includes the energy, water and CO2 emissions of the materials themselves.

The data comes from peer-reviewed scientific literature and reports from material producers whose energy and CO2 performance has been audited. The data concerns the input and output of the steps of extraction, transport and production (this input-output method is also called a resource flow analysis). Per unit of time, usually a year, we look at how many inputs (i.e. resources) are needed and how much material is produced and how many emissions are released. Raw materials, water and energy are tracked, as are the released greenhouse gas emissions. These inputs and outputs are then assigned to the amount of material produced.

The figures include the extraction of the raw material, the transport from raw material location to the factory and the production of the material. Not included in the figures is transport to the location where the product is made, the production of the product and distribution to the end customer. What is also not included is the material needed to make the machines and factories required for material production (i.e. indirect use of materials).

The figures are indicative and the spread can be read from three categories: state-of-the-art, mean and older technology. In addition, the numbers have a data quality indicator: low, medium, high or very high. The higher the indicator, the lower the uncertainty surrounding the number. The indicator can be read and applied as follows: low: greater than 30%, medium is 30%, high is 20% and very high is 10%.

The figures can be used to calculate the impact of materials contained in a product. This calculation is often referred to as an environmental impact or eco-audit. The figures are not intended to be used as a life cycle assessment (LCA) assessment.

The figures are suitable for informing decisions about product design, purchasing considerations and policy choices. Please note, no rights can be derived from the figures. In other words, the authors are not responsible for decisions made based on these figures.

The figures can provide answers to questions about the extent of energy and water consumption and the CO2 emissions of materials.

There are a number of differences between the way in which these figures and LCA figures are established:

• The figures are based on input and output data or calculations of material extraction, transport and production. An LCA usually includes the entire product cycle from extraction, transport, production up to and including distribution, use and end of life phase (recycling, incineration or otherwise).
• These figures only include (primary) energy, water and greenhouse gases. An LCA usually also deals with toxicity, impact on the ozone layer, acidification, eutrophication, depletion of raw materials and water and air pollution (i.e. these are called impact categories).
• In an LCA, measured data is used from a specific process or factory, or this data is modeled on the basis of engineering calculations for a specific process. The figures here are not measured or modeled at factory level, but are typical figures for the most common method of material production in the Europe/OECD region.
• In an LCA, the calculation, delineation, context, region and time are chosen on the basis of a specific research objective, so that the results must be read in relation to the research objective and the starting points. In other words, the outcomes are more specific but less useful broad comparisons (because research goals and assumptions differ). These figures show the energy, water and greenhouse gas performance based on inputs and outputs (i.e. resource flow analysis) in line with European guidelines.
• The figures follow the approach of the European Commission Directive 2003/87/EC and subsequent ones and are in line with the IPCC method [IPCC 2006 volume 3]. This makes the figures useful for reporting and monitoring at the material level. The numbers are not specific to factory or supplier level.

A life cycle analysis is more relevant when detailed environmental impact questions need to be answered.

The numbers are representative for Europe. In other words, the impact is representative of the European situation. In a number of cases, another region is representative (e.g. ‘world’ or ‘The Netherlands’). Where this is the case, this will be stated.

Feel free to contact us by e-mail to share data and/or propose additions for new materials. We warmly welcome this and support it where possible.

More metals, plastics and electronics will be added in the future. Detailed information, material costs and calculation modules can be found on the Circular Engine site.

The recycling content is displayed separately for the EU. The material impact for recycled materials is indicated (in the future) in its own column.

The production process is indicated as much as possible in the 'type' column.

State-of-the-art technology is the latest, most modern state of the art that is used commercially. An example is steel from a newly built steel factory.

The impact of energy, CO2 and water are all three major environmental impacts. Climate change is seen as a very important topic at the moment and information about energy and CO2 is therefore important to include. Europeans see climate change as the most important environmental topic according to the Eurobarometer Survey 2020. In the future, it will be decided whether toxicity and other information (impact factors) will be added. In addition, Circulaire Cijfers follows the European Commission’s Directive 2003/87/EC, which helps when reporting has to be done. This approach is also in line with the IPCC method [IPCC 2006 volume 3].

The most important estimates that have an impact on the figures are usually the age of the factory or installation, which is shown in separate columns labeled state-of-the-art, typical and old tech.

Several input figures and sources were used for each data point, of which as much as possible from peer-reviewed and industry published and audited figures (i.e. which have been drawn up according to a standard and have been verified by an independent party). The most reliable, up-to-date and relevant sources are weighted more heavily in the indicated base figure.

The Joule is used for energy. An amount of CO2 equivalent (also known as greenhouse gas equivalents or CO2eq) is used for the greenhouse gas impact. Water is in liters.

The sources are included in and below the table with basic figures. With your mouse, hover over the materials in the table to view the sources. For each material, the sources are presented in the manner [organization and year].