Chemical substitutes and alternatives
Where chemical hazard assessments have taken place, and action to reduce impacts is conducted, chemical substitution requires careful consideration for both suppliers and purchasers of building materials.
In some cases, a chemical of concern in a product may be substituted by another, but this may not reduce the impacts or hazards. Substitutes may be very similar substances chemically, but they may not be specifically regulated. Due to this there have been calls from legislators and environmental NGOs for more chemical family-based regulation, rather than by individual substance.
Resources to support improved substitution practices of manufacturers, that can also assist downstream purchasers of building products and chemicals, can be found in this section. These include a series of databases that have assessed substitute and alternative chemicals, as well as research papers providing guidance and raising awareness of the issue.
Chemical substitution - key considerations
There is no "one size fits all" approach to carrying out chemical substitution - different products, chemicals and use profiles will require different considerations. However, a number of guidance materials are available in this section that set out similar, material-agnostic approaches.
Some key principles that are common to many of the approaches seen for substitution or specifying an alternative include the following:
- 1. Compile a chemical inventory and prioritise
The first step needed is to identify and log the chemicals used (which may be manufactured or purchased). A prioritisation exercise can then be done to determine which chemicals are to be assessed for substitution. This depends on the goals and principles of the substitution project – the extent of the chemical hazard will be a key factor in the prioritisation exercise, but there may be other considerations such as upcoming regulations or shifts in the market towards safer chemicals. Various tools and databases are available in the conducting chemical assessment section to enable assessment of the chemical safety profile of substances under consideration.
- 2. Set a project scope and identify potential substitutes and alternatives
A set of goals and principles for substitution activities should be set. A methodology can be established which considers all the criteria that an improved product or material should achieve – alongside improved chemical safety there are likely to be performance aspects to be taken into account. This must also consider the full lifecycle of the product or material.
There may be trade-offs when reducing chemical hazards at one lifecycle stage, where another is affected, and different exposure pathways should be considered. It is also beneficial to consider if there is another way to improve the product or material by taking an alternative approach and not only considering substitution. For example, instead of substituting a flame retardant chemical for another one of lower toxicity, is there the option to use an entirely different material with naturally flame retardant properties that eliminates the need to use a chemical additive?
- 3. Assess, compare and select alternatives
From the shortlist of substitutes or alternatives compiled, the next step is to compare the different options against the methodology set and select the best options. Again, various tools found in this section or the databases page can support this process by providing details of tested or certified substitutes and alternatives.
- 4. Test, implement and improve
Pilot testing of the new substance or altered product is a key step to assess its performance and identify other aspects affected or unintended consequences. For example there may need to be changes to manufacturing processes, organisational changes or impacts on the value chain that accompany a full-scale change to a new formulation. Once there is sufficient evidence that the substitution or alternative approach is providing the intended benefit, then this can be moved towards full implementation, with appropriate change control procedures in place. This may be an iterative process, with further optimisation of the process needed beyond the initial implementation.
- 5. Inform the value chain
Clear communication with all relevant value chain actors should start at an early stage of this process – there may be implications for both suppliers and end-users of the product or material. Stakeholders may be able to provide useful inputs into testing and validation processes. Additionally, where products and materials have been improved through substitution processes, there may be benefit in promoting and publicising what has been done – this could help to gain competitive advantage in the marketplace and contribute to an overall market shift towards chemically-safer products.