In situ generation of biocides / active substance

An active substance is a substance that acts on or against harmful organisms. A biocidal product consists of at least one active substance and possibly additional substances or auxiliary substances. With in situ generation, the biocide (the active ingredient) is both generated and used on site. As soon as a biocidal product is placed on the market, it is no longer an in situ generated biocide – for example where a biocide is generated with an apparatus, but is then packaged and marketed as such.

Mandatory authorisation - NL exceptions

The legislation on biocidal products concerns the authorisation of biocidal substances and mixtures. For such substances and mixtures, authorisation is mandatory.

In principal, in situ generated biocides also require authorisation from the Ctgb before they can be used in the Netherlands. There are 2 exceptions. As long as these exceptions apply, no authorisations are required for those biocidal products. These exceptions are described in Appendix 9 of the Regulation on plant protection products and biocides (Rgb) as it was in force on 31 August 2013. That version of the Rgb remains in force until the regulation of the substances concerned is taken over by European legislation. The exceptions are:

  • Ozone that is generated on site using equipment intended for this purpose does not fall within the scope of this law.
  • Chlorine compounds that are generated on site from sodium chloride with equipment intended for this purpose do not fall within the scope of this law. This exception applies not to on site generated chlorine compounds intended for the disinfection of pipework for drinking water for humans and animals.

    The Ctgb interpretation of this last sentence is that "the disinfection of pipes for drinking water" means the disinfection of only the pipes (a PT04 application) as well as the disinfection via drinking water (a PT05 application). The Ctgb follows this interpretation because both the application for disinfection of pipes and the application in drinking water may entail potential risks to human and animal health. In addition, the exception to Annex 9 of the Dutch Plant protection products and biocidal products Regulation - known as Rgb - will expire in the near future because the European Biocides Regulation will become the guiding principle and therefore authorisation for disinfection of drinking water systems will always be required.

The Ctgb therefore recommends that in the event of disinfection of drinking water systems for humans and animals, an application should always be submitted not only for PT4 applications, but also for PT5 applications. "

These exceptions are going to expire in the Netherlands as soon as EU regulations is in force.

  • For ozone generated from air, water and oxygen, not placed on the market to serve as a precursor for ozone, a substance dossier is submitted for the uses as PT2, 4, 5 and 11. The exception will expire after the European approval of ozone. Ozone used in other product types or generated from other substances then air, water and oxygen, not placed on the market to serve as a precursor, must be removed from the market since September 1th, 2017.
  • For chlorine compounds generated from sodium chloride a substance dossier has been submitted for  uses  PT1, 2, 3, 4, 5, 11 and 12. When a decision has been taken on the approval of the active substance for these Pt it will become clear when the exception in Dutch national law  will expire. For the other Pt, chlorine compounds generated from sodium chloride and used as a biocidal product must be removed from the market no later than 1 September 2017.

More information on biocidal active substances can be found in the ECHA database.

What aspects are given an authorisation with in situ generated biocides?

In situ generated biocides are made on site from one or more precursors or from generally available substances (such as sea water or air).
If there are one or more precursors, then the regulations for authorisation of biocidal products apply to the precursors.

With in situ generation of biocides, three situations are possible:

  1. A precursor is used that is placed on the market specifically for that purpose.
  2. A precursor is used that is not placed on the market specifically for that purpose.
  3. No precursor is used
  1. If a substance or mixture is placed on the market with the claim of serving as a precursor for the in situ generation of a biocide, then that product must be authorised by the Ctgb.

    For example: copper and silver electrodes that are placed on the market to be used specifically for the disinfection of drinking water; (see authorisation 13292N).
    In the future, an authorisation will be required for using sodium chloride for disinfection of swimming water. The authorisation will apply to the sodium chloride. The applicant can choose to request an authorisation for sodium chloride that is intended to be used specifically in apparatus manufactured by firm X. In this way, a specific link is established between that sodium chloride and the specific apparatus manufactured by firm X.
    The applicant can also choose to request an authorisation for sodium chloride that can be used in apparatus manufactured by multiple firms for the generation of chlorine compounds. In that case, however, the application must demonstrate that all of these types of apparatus can generate the desired biocide on site from that sodium chloride.

  2. If an apparatus will be used for the in situ generation of a biocide with the aid of a precursor, but the precursor does not have an authorisation from the Ctgb, then this is an illegal situation. In principle, all precursors require an authorisation from the Ctgb for use in apparatus intended for generating a biocide. Or the reverse: such apparatus can only be used in combination with a precursor that has been authorised. However, there is one important exception to this rule: for chlorine compounds that are generated on site from sodium chloride, no authorisation is required unless the intended use is for disinfection of pipes for drinking water for humans or animals. This exception will expire in the future.

  3. If no precursor is used, but only a generally available substance such as seawater or air, then no authorisation can be required for that generally available substance. Consequently, an authorisation will be issued for the in situ generated substance (ozone) that is generated with specific apparatus manufactured by firm Y. In this way, a link is made between the in situ generated biocide and the specific apparatus with which this generation must take place. Obviously, firm Y (which manufactures the apparatus) will request this authorisation. Firm Y will therefore submit an application for authorisation of ozone generated with their specific apparatus. The application must also include data about the ozone as it is generated with the corresponding apparatus. Here as well, the applicant can choose to request an authorisation for ozone that is generated on site with various brands of apparatus. The application must also demonstrate that all types of apparatus named in the application are capable of generating the desired ozone.

What about the equipment?

Under the Biocidal Products Regulation, authorisation of apparatus is not strictly necessary. However, if no precursor is marketed (case 3 above), then the generated substance in combination with the apparatus is authorised; in practice the manufacturer of the apparatus will request an authorisation for this apparatus.
There is also a difference in the period until 1 September 2017 and the period thereafter.

The precursor will be authorised (f.e. cupper/silver electrode); if that is not possible (f.e. in case ozone is produced out of air) then the generated active substance is authorised.

In all cases of in situ generation it is possible to request the Ctgb for authorisation of the precursor or the in situ generated substance in combination with the apparatus. F.e.: in situ produced ozone with a generally available substance such as air using a appartus manufactured by firm Y.

Data requirements

With regard to information on data requirements, the section on the ECHA website includes the BPC Working Groups recommendation (In situ generated active substances – Risk assessment and implications on data requirements for active substances generated in situ and their precursors) was drafted with regard to the technical requirements on in situ generated substances and the definitions used. In addition, the CA guidance on free radicals generated in situ is available.

For ozone, specific agreements were made, published in CA document CA-May15.Doc.5.1.a final. This document is not made available on the ECHA, but can be retrieved from the CIRCABC site.

General information

General information about in situ generated substances, procedures and guidance can be found on the ECHA website - In situ generated substances. Here you will find also additional relevant documents as: