In situ generated active substances

Exploring In Situ Generated Active Substances: Definitions, Authorizations, and Re-definitions

In situ generated active substances can be defined as substances, which are generated at the place of use from one or more precursors.

For in situ generated AS. The biocidal product, requiring authorization prior to supply or use, falls into either of these categories:

  • the substance(s) or mixture(s) generating the active substance; or
  • the active substance generated from substances or mixtures, which cannot themselves be authorisedas biocidal products.

All substances produced on-site require a clear definition through referred precursors in the dossier under review. This applies to both the active substance and the resulting product.

In specific instances, this might cause substance re-definition. The substance was initially notified or new entries formed. Data on several precursors in a dossier or from multiple dossiers for a substance. For example, chlorine dioxide’s definition could change. It could be produced through electrolysis from sodium chlorite, or from sodium chlorate and hydrogen peroxide using a potent acid.

In situ generated active substances


Substance approval

Upon substance approval, the Commission Regulation will cite supported precursor(s) and resultant active substance, along with the relevant generation method.

In the case of in situ generated active substances, the dossier or LoA will need to cover data on both the in situ generated active substance and the precursor(s), which form the representative product, supported in the dossier under evaluation.