Co-formulants under Reg. (EC) No. 1107/2009 “The negative list”

The EU “negative” list of co-formulants, that can no longer be included in pesticide formulations in the EU-27, EEA and UK-NI, was published in March 2021, amending Annex III of Regulation 1107/20091. The EU ‘negative’ list contrasts with the US, where a ‘positive’ list of permitted co-formulants (‘inert ingredients’) is used2.

Co-formulants are defined in the Regulation as substances or preparations, which are used or intended to be used in a plant protection product or adjuvant but are neither active substances nor safeners or synergists.

Co-formulants with certain properties are not permitted in pesticides – for example:

  • if their residues have a harmful effect on human or animal health or on groundwater or an unacceptable effect on the environment.
  • if classified as carcinogens, category 1A or 1B, as mutagens, category 1A or 1B, or as toxic to reproduction, category 1A or 1B.
  • if they are identified as persistent, bio-accumulative, and toxic (‘PBT’) or very persistent and very bio- accumulative (‘vPvB’)
  • if they are substances of “very high concern” due to endocrine disrupting properties

For products containing a co-formulant listed in Annex III, Member States may grant a very short grace period for sale and distribution up to only 3 months and for the disposal, storage and use for an additional 9 months after withdrawal of the authorisations.

The concentration of the unacceptable co-formulants in the finished plant protection product or adjuvant should normally be less than 0,1 % weight by weight (w/w) to be considered as an acceptable unintentional impurity, unless a different limit is provided due to technical limitations of relevant analytical methods.

Examples of co-formulants no longer permitted in pesticide formulations:

  • Polyethoxylated tallow-amines
  • Nonyl-phenols
  • Quinoline

Note that four compounds linked to crystalline silicates are currently under review as ‘basic substances’ as follows:

  • quartz
  • kaolin
  • kieselgur
  • talc

While limits on crystalline silica were indicated in earlier drafts of the co-formulant negative list, they were removed from the final list as not classified and triggering a range of problems linked to concurrent use in horizontal sectors (cosmetics, pharmaceuticals, etc) and unavoidable natural background concentrations, for example with beach sand.

However, it is considered likely that any harmonised restrictions in the content of respirable dust particles in the basic substance review (e.g. max. content of crystalline silica particles smaller than 10 µm must be <0.1%w/w in the formulation), will be applied to their use as co-formulants e.g. in GR formulations. One open question remains if the content limit of <0.1%w/w will apply at the product level or the co-formulant level, remembering that this will also likely need to be tested both before and after storage of the product.

With the very short grace periods permitted in the Regulation, it is advised to proactively ensure that current
formulations containing any one of the ‘basic substances’ above are tested to ensure that the particles smaller than 10 µm remain 0.1%w/w. (NB. the detection of the crystalline silica fraction in these particles may not be feasible, so the assumption in the absence of data, is that 100% of these particles are crystalline silica).

Please contact us for further information: Garth DRURY

1 COMMISSION REGULATION (EU) 2021/383 of 3 March 2021 amending Annex III to Regulation (EC) No 1107/2009 of the European Parliament and of the Council listing co-formulants which are not accepted for inclusion in plant protection products.