Introduktion til CØ-tool (på engelsk)


In order to understand whether the substitution of one or more hazardous substances, used in the processes or the products of a company, is helping in moving towards a more circular economy, we look at the material, water and energy flows before and after the substitution.   

Each input material used in the production process comes with an “ecological rucksack”, that is an amount of non-renewable abiotic materials removed from nature to create that input material.  Certain amounts of water and energy have also been used to create it.   

The substitution of a hazardous substance may modify the input materials, the energy and the water used in the production process.  It may also enhance the “recyclability profile” of the output materials, that is the products, packages and waste flows of the production process. 

The tool compares the intensity factors of the production process before and after the substitution. The intensity factors are the amount of materials, energy and water used and general and hazardous waste generated per each unit of output (that could be the weight of output in kg or per a unit service defined).

The results show how the substitution has affected the different factors considered (e.g. the substitution may have increased the amount of input materials required to produce one product but it may have decreased the amount of hazardous waste generated of the energy required in the production process).

It is important to note that only a thorough assessment can determine whether substituting a chemical of concern is the right final decision.  In this simplified life cycle assessment, we use average factors based on information from third parties and literature, for which we cannot guarantee the accuracy. 

The primary objective of the tool is therefore to highlight the information required to assess the contribution of the substitution on moving towards the circular economy. 


The following information is required in order to use the tool:

  • The identity of the substance to be substituted (name and CAS number)
  • The alternative chosen (name and CAS number, if the alternative is a substance)
  • The hazard classifications of the substance to be substituted and of the alternative chosen (if the alternative is non-chemical, the fields can be left blank); 
  • The total weight (in kg) of the input materials before and after the substitution;
  • The type of input materials (chemicals, metals, plastics, paper and wood, ceramics and glass, composites) by percentage on the total weight of input materials before and after the substitution;
  • The percentages of recycled input materials (as their material, energy and water intensity factors are different) before and after the substitution;
  • The energy and water used (respectively in kWh and litres) before and after the substitution;
  • The weight of products and packages (in kg) before and after the substitution;
  • The weight of hazardous and general waste (in kg) before and after the substitution;
  • The percentage of products, packages and general waste recycled before and after the substitution;
  • A Unit of Service and the number of Service Units before and after the substitution.  The Service Unit is the measure of comparison and is the service delivered by the product. It can be a measure of time (e.g. number of years of service life of an electric cable) or a measure of the number of "uses" of the product (e.g. number of times a T-shirt -the product - is worn). 


You can find an example of a substitution case (based on a real case) for which we provide all the information required to use and test the tool here.

We value your opinion

We would really appreciate if you could answer few questions on the usability of the tool. Your feedback will help us in refining it.

Please, fill in the document "FeedbackUsability"  (editable pdf) and send your feedback to us

Go to CØ-tool 

Senest ændret: mandag, 15. oktober 2018, 14:48