Biocides for cooling water and metalworking: DBNPA and the formaldehyde releasers HPT and MBO approved for at most five years as candidates for substitution, HPT not for fuel preservation — acts (EU) 2026/373, 385, 577 and 599
In February and March 2026 the Commission decided on three active substances meeting the exclusion criteria of Regulation (EU) No 528/2012. Implementing Regulation 2026/577 approves 2,2-dibromo-2-cyanoacetamide (DBNPA) for product-type 11 only for short-term (up to 14 days) preservation of water in closed and open cooling systems. Regulations 2026/373 and 2026/385 approve formaldehyde released from the reaction products of paraformaldehyde and 2-hydroxypropylamine in the ratios 1:1 (HPT) and 3:2 (MBO), and Decision 2026/599 does not approve HPT for product-type 6 (fuel preservation).
- DBNPA (EC 233-539-7, CAS 10222-01-2, purity at least 98.0%): ECHA found that it has endocrine-disrupting properties for humans and non-target organisms. In both uses — closed and open systems — 96 active substances were examined as alternatives — oxidisers proved too corrosive and incompatible with water treatment additives, while the rest act too slowly; non-chemical methods (UV, electrolysis, membrane filtration, heat treatment and others) were considered only a complement. For open cooling systems the risk of spreading Legionella was decisive.
- The DBNPA approval runs from 1 July 2027 to 30 June 2032, for industrial and professional users only. Articles treated with or containing DBNPA may not be placed on the market, and a Member State may authorise a product only after demonstrating on its territory the conditions of Article 5(2)(b) or (c) of Regulation 528/2012.
- HPT and MBO are classified as carcinogenic category 1B. They were nevertheless approved from 1 June 2027 to 31 May 2032: HPT for product-types 2, 11 and 13, MBO for product-types 2, 6, 11, 12 and 13 — among others for cleaning formulations in metalworking systems, cooling fluids in closed systems and metalworking and cutting fluids, and MBO also for fuel preservation and slimicides in offshore oil extraction installations. Both are UVCB substances, so the minimum purity is given as 1,000 g/kg.
- HPT was rejected for product-type 6 because a majority of Member States in the Standing Committee on Biocidal Products considered MBO a suitable and sufficient alternative for fuel preservation — contrary to ECHA’s opinion of 23 November 2023, which had not assessed MBO as an alternative (the applicant itself acknowledged MBO to be the most appropriate biocidal solution for fuel preservation). It was also not shown that HPT is essential to prevent a serious danger, and because the risk linked to endocrine disruption remains unresolved the risk cannot be considered negligible. For laboratories testing metalworking fluids and fuels this indicates which preservatives will remain on the market after 2027.