Biocidal products with precursors for the in-situ generation of active substances
In situ generated active substances can be defined as substances which are generated at the place of use from one or more precursors.
Under the terms of the the European regulations on biocidal products (BPR; EU nr. 538/2012) and the Swiss Federal Ordinance on Biocidal Products (OBP, 813.12), active substances generated in situ, and the associated precursors, are considered to be biocidal products and are thus subject to approval.
Under the terms of the BPR and OBP, an active substance is authorised for specific applications known as product types (OBP, Annex 10). For this reason we talk of precursor/active substance/product type combinations.
It is important to note that any precursor substances that are marketed for non-biocidal purposes (for example sodium chloride used as softening salt) are not subject to this regulation and therefore do not require approval under the terms of the OBP.