Below, relevant points regarding the evaluation of co-formulants (as constituents of plant protection products), adjuvants, and safeners and synergists are highlighted. Note that only for adjuvants a formalized Regulatory framework is not yet available.
Co-formulants
Co-formulants are used in plant protection products and adjuvants to bestow a desired functionality, though they are not categorized as active substances, safeners, or synergists. Evaluation of the (eco)toxicological potential of co-formulants is an intrinsic part of any PPP-assessment, but as of March 24th 2021, hazards associated with constituents of co-formulants are more restrictively governed through Regulation (EU) 2021/383.
The Regulation provides the first amendment to the Annex III list of unacceptable co-formulants, referred to in Article 27 of Regulation (EC) No 1107/2009. Subsequent Regulation (EU) 2023/574 within this context sets out detailed rules for the identification and notification of candidate substances for Annex III inclusion and furthermore establishes ten criteria based on which these candidates may be notified (see directly below for more information).
The first group of substances notified according to (EU) 2023/574 have been added to Annex III as an effect of Regulation (EU) 2026/1120. Please refer to (EU) 2026/1120 for more information on timelines for compliance.
Notification of co-formulants for inclusion in Annex III of (EC) No 1107/2009 through Reg. (EU) 2023/574
According to Regulation (EU) 2023/574, a check must be carried out for potentially unacceptable co-formulants within all applications for authorisation, change or renewal of a product, submitted from 3 April 2023 onwards. During this check, the co-formulants in the respective product are screened for ten criteria, which are described in the Annex of (EU) 2023/574. If a co-formulant meets one or more criteria, it can be considered unacceptable on the basis of its (eco)toxicologically harmful properties.
In that case, a procedure is initiated to notify the substance for inclusion in Annex III, with the ultimate goal of strongly restricting/phasing out its use as a co-formulant in plant protection products within the EU.
Regulation (EU) 2023/574 is an addition to Regulation (EU) 2021/383.
Adjuvants for plant protection products
Adjuvants are defined as mixtures or preparations which are marketed separately and are mixed with a plant protection product before use. Examples of adjuvants are anti-foaming agents, wetting agents, uptake enhancers and sticking agents. Like co-formulants, adjuvants are subject to Regulation (EU) 2021/383 (entry into force: March 24th 2021) that puts a restriction on the presence of hazardous substances in these commodities (see ‘Co-formulants’ for more information).
Safeners and synergists
A work programme for gradual review of safeners and synergists that are already on the European market has been established in Commission Regulation (EU) 2024/1487, along with formalised data requirements for both approval -and authorisation level.
Safeners and synergists included in the work programme are listed in Annex I to (EU) 2024/1487, as amended by Commission Regulation (EU) 2025/2274