K-HDO Biocide Extension for Wood: What Manufacturers and Distributors Must Do in 2026

Key data

If you manufacture, distribute or use wood protection biocides containing K-HDO, this decision directly affects you. The European Commission has extended the authorization of this active substance because the scientific evaluation process has not been completed within the planned timeframe. While the extension lasts, you do not need to withdraw any products from the market or request emergency new authorizations.

Commission Implementing Decision (EU) 2026/2119, published on 25 September 2026 in the EU Official Journal, is based on Regulation (EU) No 528/2012 on biocides, which provides for exactly this extension mechanism when evaluation is not completed on time. It is not an exception: it is the standard procedure to ensure market continuity.

What does this regulation establish?

The decision has a specific and limited objective: to delay the expiration date of K-HDO approval as an active substance in biocides of product type 8 (wood preservatives) until the ongoing European scientific evaluation is completed.

The key points it establishes are:

• K-HDO approval does not expire on the originally planned date.
• The new deadline will be set based on the result of the scientific evaluation, which has not yet been completed.
• During the extension period, biocidal products containing K-HDO may continue to be marketed and used legally throughout the EU.
• No immediate product withdrawal or reformulation action is required.
• The final result of the evaluation could entail additional restrictions, stricter conditions of use or, in the worst case, non-renewal of approval.

K-HDO is an active substance used specifically in biocides of product type 8, a category that groups products intended to protect wood from its transformation to its final use, including preventive and curative treatments against wood-destroying organisms (fungi, insects, etc.).

Economic and operational impact

In the short term, the direct economic impact of this decision is neutral or positive for companies in the sector: supply disruptions are avoided, there are no product withdrawal costs and the supply chain is not interrupted.

However, there are two economic and operational risks that must be managed:

• Medium-term regulatory uncertainty: If the scientific evaluation concludes with restrictions or additional conditions, companies will need to reformulate products, update labels, revise safety data sheets and potentially request new product authorizations. These processes have significant costs in time and resources.
• Risk of non-renewal: If the evaluation concludes with non-approval of K-HDO, products containing it will have to be withdrawn from the market within the timeframes set by the Commission. This implies loss of product lines and need for urgent reformulation.

The decision also guarantees market continuity and prevents supply disruptions in the wood protection sector, which has real economic value for the entire chain: biocide manufacturers, wood treatment companies, industrial carpentry shops and construction companies using treated wood.

Who does it affect?

• Biocide manufacturers that produce wood preservatives with K-HDO as the active substance.
• Distributors and marketers of type 8 biocidal products in the European market.
• Professional users of wood protection biocides: wood treatment companies, industrial carpentry shops, construction companies and maintenance companies.
• Compliance and regulatory affairs managers in chemical and construction materials companies.
• Importers and exporters of biocidal products with K-HDO within the European single market.

Practical example

Imagine a Spanish wood protection manufacturer that has three products in its catalog formulated with K-HDO as the main active substance. The European approval of K-HDO was about to expire, which would have forced the company to consider preventive withdrawal of those products or to accelerate costly reformulation.

With Commission Implementing Decision (EU) 2026/2119 in force since 23 September 2026, this company can continue manufacturing, marketing and supplying those three products without any interruption. It does not need to withdraw stock, does not need to reformulate urgently and does not need to communicate any changes to its customers for immediate regulatory reasons.

What it must do is activate a system to monitor the European evaluation process: when the European Chemicals Agency (ECHA) publishes its opinion and the Commission adopts the final decision, the company will have to act quickly, either to adapt its products to the new conditions or to plan the replacement of K-HDO if the substance is not renewed.

What should companies do now?

1. Verify if your products contain K-HDO: Review the list of active substances of all your type 8 biocides. If any includes K-HDO, this regulation directly affects you.
2. Confirm that you can continue operating: During the extension period, the marketing and use of products with K-HDO is completely legal in the EU. No immediate withdrawal or reformulation action is necessary.
3. Activate an alert system for the European evaluation: Monitor publications from ECHA (European Chemicals Agency) and the EU Official Journal to detect as soon as the result of the scientific evaluation of K-HDO is published.
4. Prepare a contingency plan: Evaluate what would happen to your product portfolio if the evaluation concludes with restrictions or non-renewal of K-HDO. Identify possible alternative substances and estimate reformulation costs.
5. Communicate internally the regulatory status: Inform product, sales and procurement teams about the current situation: products are legal, but there is medium-term uncertainty that must be monitored.
6. Review long-term supply contracts: If you have supply contracts for products with K-HDO that extend beyond the extension, include regulatory review clauses to protect yourself against possible changes.

Official source

Consult the complete regulation in the official source

Disclaimer: This article is for informational purposes only and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://eur-lex.europa.eu/./legal-content/AUTO/?uri=OJ:L_202602119