Commission Implementing Decision (EU) 2026/2125 of 24 September 2026 allowing Latvia to authorise biocidal products containing ethylene oxide for the protection of cultural heritage (notified under document C(2026) 6649)

Ethylene oxide in product-type 2 (disinfectants and algaecides not intended for direct application to humans or animals), as defined in Annex V to Regulation (EU) No 528/2012, was included in the work programme for the systematic examination of all existing active substances contained in biocidal products referred to in that Regulation, as set out in Annex II to Commission Delegated Regulation (EU) No 1062/2014 (2). An application for approval of ethylene oxide in product-type 2 was submitted on 1 December 2009.

Commission Implementing Decision (EU) 2025/1074 (3) found that the representative product included in the application for approval was not within the scope of Regulation (EU) No 528/2012 and that, as a consequence, it was appropriate to not approve ethylene oxide as an active substance for use in biocidal products of product-type 2.

Pursuant to Article 55(3) of Regulation (EU) No 528/2012, on 25 November 2025, Latvia submitted to the Commission an application for a derogation from Article 19(1), point (a), of that Regulation, in which it asked to be allowed to authorise biocidal products containing ethylene oxide for the protection of cultural heritage, specifically for the protection of archive material.

According to the information provided by Latvia, the use of ethylene oxide is essential for the protection of archive material, since it appears to be the only efficient technique to control harmful organisms that can threaten such material and in particular mould. Historically, a formaldehyde disinfection chamber was installed at the National Archives of Latvia and was used until around 2010, when it was decommissioned due to the carcinogenic effects of formaldehyde reported in scientific literature. Ethylene oxide was identified by Latvia as a potential alternative to formaldehyde. However, considering the hazard profile of ethylene oxide, additional studies were carried out at Riga Technical University to determine residual ethylene oxide levels after disinfection of books, showing that the residual amounts were insignificant. Disinfection with ethylene oxide is carried out only by trained personnel in specialised, purpose-built facilities, following a strict and controlled process. After disinfection, a multi-stage aeration phase is carried out, to remove gas residues from the objects.

As indicated by Latvia in the application, there are no available appropriate alternative techniques for the treatment of archives. in Latvia. No facility for gamma radiation exists in Latvia. The nearest facility is located in Estonia, where the material to be treated would need to be transported, involving logistical risks and delay of the treatment. Moreover, according to Latvia, scientific studies have shown that the radiation doses required for effective disinfection show significant cellulose degradation, which considerably reduces the long-term stability and durability of documents. The method of freezing can stop the growth of mould but is ineffective against spores. Alcohol-based solutions can be used only if the mould infestation is low. However, according to Latvia, they do not guarantee spores destruction and cannot always penetrate the inter-fibre spaces of paper, where viable spores may remain.

The information and justification contained in the application submitted by Latvia shows that the use of ethylene oxide is essential for the protection of cultural heritage and that there are no appropriate alternatives for the treatment of archive material, since all the currently available alternative techniques are either not sufficiently effective or can cause damage to the material treated.

Based on the information and justification provided by Latvia, it is appropriate to conclude that ethylene oxide is essential for the protection of cultural heritage in Latvia and that no appropriate alternatives are currently available in Latvia. Latvia should therefore be allowed to authorise biocidal products containing ethylene oxide for the protection of cultural heritage, specifically for the protection of archive material,