Substitution

Substitution means removing or replacing hazardous chemical substances in products with less hazardous or non-chemical alternatives. The purpose is for the products to be safer for health and the environment when they are manufactured and used, and when they become waste and possibly are recycled. A seven-step model is presented here that can form the basis for a systematic work to select or replace substances as a way of preventing and avoiding risks. For many companies, substitution of hazardous chemicals is already a natural part of the ongoing work of development and improvement.

E-flask with blue-green liquid in it and molecules

A thorough review and assessment of alternatives reduces the risk of regrettable substitution

It is a good idea to start by defining the problem with the use of a substance. Then possible alternatives should be identified. The selection should be as wide as possible and the focus should be on replacing the function of the substance that needs to be substituted. A thorough review and assessment of alternatives reduces the risk of regrettable substitution, i.e. that a problematic substance is replaced by another problematic substance.

Start by thinking about why the substance in question should be replaced and what function the substance has. Describe in as much detail as possible why the substance is problematic and in what way. These questions can be helpful.

  • Why is the substance a problem?
  • Where and when does the problem occur? Is it in your business or when the product has been resold?
  • For whom is the substance a problem, who suffers from it?
  • What function does the substance to be replaced fulfil?
  • How important is the function?
  • Is an equivalent function difficult to achieve in another way?
  • Is there a corresponding function in other products?

The next step is to identify alternatives or technical solutions that can achieve the same function as the substance to be replaced. Sometimes it is possible to find alternative solutions where chemicals are not necessarily included. Remember that replacing a hazardous substance with another substance within the same substance group may be problematic. At this stage, it is important not to be limited by practical or economic arguments. Ask yourself the following questions.

  • How would you have solved the problem if you had not had access to the substance in question?
  • Can a change in the manufacturing process or in the product design (e.g. switching to another material) make that the substance is not needed at all?
  • Can the product be replaced with another product that has an equivalent function but with a different composition or new technical solution?

A thorough review and assessment of alternatives reduces the risk of regrettable substitution, i.e. that a problematic substance is replaced by another problematic substance. When assessing the alternatives, you should consider parameters such as hazardous properties, technical performance, costs, and the life cycle of the substance. What can happen if the product in question is replaced with one of the alternatives. An alternative is not always obviously better. Think about questions such as:

  • What are the hazardous properties for health and the environment of the alternative products?
  • For example, what is economically and practically feasible?
  • What tests on, for example, technical performance must be performed?
  • How is quality and function affected by the alternative method or substance?
  • How can the alternative technology or process affect humans or the environment in a life cycle perspective?
  • In what ways can humans or the environment be exposed to the alternative product or residual products during manufacture, use, in the waste phase or during recycling?

Once you have assessed the different alternatives, it is time to compare the risks of the alternatives with the risks of the product you want to replace. How big the risk of using a substance is depends on how dangerous it is and how much exposure and what exposure there is. Here, the risks in use between the current substance and the substitutes are compared, and not the environmentally and health hazardous properties of the individual substances.

  • Is there a big difference in exposure between the different alternatives?
  • Are there any of the products that humans or the environment are more likely to be exposed to?
  • If humans or the environment are expected to be equally exposed to the various alternatives – what damages can occur in the environment or in humans?
  • How easy is it to limit the risks with the alternative product or method compared to the one you are using now?
  • If there is a risk of harm to humans or the environment, how can the risks be limited?

In this step, it is time to decide which alternative or technical solution you are moving forward with. Hopefully you have a good basis that gives you the opportunity to make a well-founded decision.

  • Are the alternatives on my list better than the problematic one?
  • When can the product / process be replaced with the alternative?
  • Economic analysis - what will the cost be for the different methods?

To phase out a chemical and replace it with something new usually requires careful planning. Think about what needs to be done in connection with the replacement of a product or process with a new one.

  • Who is responsible for the various steps that need to be taken and what does the timetable look like?
  • When can the alternative process / product be taken into use and placed on the market?
  • Do the company's customers need to be informed?

After you have replaced a substance, it may be good to make an evaluation. Document and describe in detail how each part of the substitution work was carried out and what decisions were made on the available data. This can be of support and help at the next substitution.

  • Compare the results with the problem description you made in step one and see if the expectations have been met.
  • Solve any problems that remain.
  • Feel free to share your experiences with others!

Substitution is a continuous work

Substitution is a continuous work. The alternatives may need to be re-evaluated if there are new research findings regarding environmental and health risks, new rules or new and better solutions. Therefore, continue to work for a continuous improvement of products and processes in terms of risks with chemical products or articles containing chemicals hazardous to health and the environment. Once you have taken the first step, it is easier to continue. Companies that replace hazardous chemicals with less hazardous ones contribute to the development towards a non-toxic circular economy and can also achieve competitive advantages.

Read more about substitution of hazardous substances on the Swedish Chemicals Agency´s website

The Swedish Centre for Chemical Substitution – provides guidance on chemical substitution

The Swedish Centre for Chemical Substitution at RISE works with advice in substitution of hazardous chemicals for companies, public sector or organisations. The centre has produced the Substitution Guideexternal link that provides practical advice and recommends tools and resources that can be useful in your substitution work.

Last published 7 January 2021