By using biocidal products Disinfection By-Products (DBPs) can be formed. DBPs could cause a risk for human health and environment.
In January 2017 ECHA made the final guidance on Disinfection By-Products available, being in force from January 2019.
The guidance on Disinfection By-Products provides a strategy for the human health and environmental risk assessment of DBPs to the applicants and the competent authorities. The human health risk assessment is based on a set of known marker DBPs, using consensus health-based limit values and DBP concentrations. For the Human health aspect the guidance focuses on PT2 in swimming-pool water for which human exposure was considered most relevant while discussing the exposures to DBPs from PT2, 11 and PT12.
In PT2 besides use of biocidal products in swimming pools, also other applications are included for which a DBP-assessment may be needed. This could also be relevant for other PTs: PT1, PT4 and PT5, followed by PT3, PT11 and PT12. It is recommended to further investigate the applicability of the present guidance to these other exposures in PT2 and other PTs.
The environmental risk assessment is predominantly focused on the determination of the risks of DBPs formed during use or in the waste phase of the biocidal product and directly or indirectly emitting to surface water. This focus can be relevant for applications for all product types (although most applications will concern disinfection (PT2 to 5), PT11 and 12. Note that in some cases also soil could be a relevant receiving compartment..
Further general information is described in the guidance on Disinfection By-Products.
Disinfection by-products may also be relevant for other biocides than halogen-containing biocides, like in situ generated free radicals.