Conclusion on the peer review of the pesticide risk assessment of confirmatory data submitted for the active substance diflubenzuron

On 1 January 2009, Diflubenzuron was included in Annex I to Directive 91/414/EEC by Commission Directive 2008/69/EC (amended by Commission Directive 2010/39/EU), and has been deemed to be approved under Regulation (EC) No 1107/2009, in accordance with Commission Implementing Regulation (EU) No 540/2011, as amended by Commission Implementing Regulation (EU) No 541/2011. It was a specific provision of the approval that the notifier was required to submit to the European Commission further studies on the potential genotoxicity of the impurity and metabolite 4-chloroaniline (PCA) by 30 June 2011. In accordance with the specific provision, the notifier, Chemtura Netherlands B.V, submitted an updated dossier in June 2011, which was evaluated by the designated RMS, Sweden, in the form of an Addendum to the Draft Assessment Report. In compliance with Guidance Document SANCO 5634/2009 rev.3, the RMS distributed the Addendum to Member States and the European Food Safety Authority for comments on 20 December 2011. The RMS collated all comments in the format of a Reporting Table, which was submitted to the European Commission in April 2012. Following consideration of the comments received, the European Commission requested the EFSA to organise a peer review of the RMS’s evaluation of the confirmatory data submitted in relation to the potential toxicological relevance of the impurity and metabolite 4-chloroaniline (PCA) and to deliver its conclusions on the risk from exposure to PCA via intake of or exposure to diflubenzuron for consumers, residents/bystanders and workers. The experts at the Pesticides Peer Review Meeting on mammalian toxicology (PPR 92) in July 2012 concluded that PCA as a metabolite in both humans and rats should be considered as a transient non-isolatable metabolite after exposure to diflubenzuron. The rat should be considered an appropriate model for human exposure to diflubenzuron where a genotoxic and carcinogenic potential was not observed. However, it is noted that the concentration of the carcinogenic impurity PCA in the batches tested in the carcinogenicity studies is still unknown. The EFSA in 2009 identified a critical area of concern concerning the lack of a peer reviewed specification and assessment of the equivalence of the batches tested in all the mammalian toxicity studies compared to the representative specification. The EFSA considered it particularly important because of the unknown concentration of the PCA in the batches tested in the carcinogenicity studies. The experts considered that potential exposure to PCA as a residue (i.e. either for consumers or for workers and bystanders/residents) should be considered a priori as a concern since a threshold for a genotoxic carcinogen cannot be assumed.

EFSA, 22 August 2012 ; ;