Potential for substitution of substances used in wood preservatives (PT8) - Issues related to future approval decisions - October 2022

Most of the wood species grown in France do not have sufficient natural durability to withstand the
biological stresses to which they are subjected over long periods of time when put into service,
particularly in the fields of construction (carpentry, cladding, etc.) and logistics. Wood treatment is used
to provide the desired durability to the wood being used. And of all the options available, treatment with
fungicides and insecticides is the most common route.
As such, (chemical) wood preservatives are regulated by EU Regulation 528/2012 on the placing on the
market and use of biocidal products and may only use approved active substances, whose approval is
periodically reviewed.
The first objective of this study is to identify, prior to the re-approval deadlines, the substances for which
substitution issues might be necessary even though they are widely used. With different degrees of
urgency, four active substances - creosote, propiconazole, boric acid and tebuconazole - stand out.
The second objective of the report is to investigate to what extent alternatives are possible for each of
these biocides. When combined with the study of the characteristics of all products available on the
market, the analysis of the expected uses of each substance leads to the conclusion that all types of
use can be covered with alternative active substances that do not meet any exclusion criteria (some
uses can also be covered by non-biocidal treatments). The conclusion is particularly true for
propiconazole, even though a significant part of the wood treatment industry has developed around its
use.
This report does not provide a detailed socio-economic analysis of the impacts associated with the
substitution of these active substances. However, it suggests that substitution could have significant
impacts on the industry, which has invested little in research into new active substances and remains
highly dependent on the few active substances currently available. It should also be noted that wood
treatment elsewhere in Europe is also very dependent on a few substances (notably boron compounds)
which are not widely used in France but which also meet the exclusion criteria. To date, the safest
alternative solutions (chemical or not) are proposed by a small number of companies.