Conclusion on the peer review of the pesticide risk assessment of the active substance 1,4-dimethylnaphthalene


European Food Safety Authority
EFSA Journal
EFSA Journal 2013;11(10):3229 [43 pp.].
Conclusion on Pesticides
On request from
European Commission
Question Number
15 May 2013
18 October 2013
European Food Safety Authority (EFSA), Parma, Italy
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The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State the Netherlands for the pesticide active substance 1,4-dimethylnaphthalene are reported. The context of the peer review was that required by Commission Regulation (EU) No 188/2011. The conclusions were reached on the basis of the evaluation of the representative use of 1,4-dimethylnaphthalene as a sprout suppressor on potatoes. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.


1,4-dimethylnaphthalene is a new active substance for which in accordance with Article 6(2) of Council Directive 91/414/EEC the Netherlands (hereinafter referred to as the ‘RMS’) received an application from DormFresh Ltd for approval. Complying with Article 6(3) of Directive 91/414/EEC, the completeness of the dossier was checked by the RMS. The European Commission recognised in principle the completeness of the dossier by Commission Decision 2010/244/EU.

The RMS provided its initial evaluation of the dossier on 1,4-dimethylnaphthalene in the Draft Assessment Report (DAR), which was received by the EFSA on 21 March 2012. The peer review was initiated on 30 March 2012 by dispatching the DAR for consultation of the Member States and the applicant DormFresh Ltd.

Following consideration of the comments received on the DAR, it was concluded that the EFSA should conduct an expert consultation in the area of mammalian toxicology and the EFSA should adopt a conclusion on whether 1,4-dimethylnaphthalene can be expected to meet the conditions provided for in Article 5 of Directive 91/414/EEC, in accordance with Article 8 of Commission Regulation (EU) No 188/2011.

The conclusions laid down in this report were reached on the basis of the evaluation of the representative use of 1,4-dimethylnaphthalene as a sprout suppressor on potatoes as proposed by the applicant. Full details of the representative uses can be found in Appendix A to this report.

In the area of identity, physical/chemical/technical properties and methods of analysis data gaps were identified for data to address the extraction efficiency of the analytical method for 1,4-dimethylnaphthalene in high water content matrices, validated method for analysis of 1,4-dimethylnaphthalene in plant materials of high acid content, high oil content and dry matrix groups; ILV, confirmatory data and extraction efficiency verification for  the method for analysis of 1,4-dimethylnaphthalene in eggs, meat, liver, skin and fat and validated method for analysis of 1,4-dimethylnaphthalene in milk.

No critical areas of concern were identified in the mammalian toxicology section, but a data gap for the relevance of impurities.

Based on the available data and pending the submission of a new metabolism study, the residue definition for potato was proposed a 1,4-dimethylnaphthalene for monitoring and as sum of 1,4-dimethylnaphthalene and its metabolites M21 and M23 expressed as 1,4-dimethylnaphthalene for risk assessment. For animal products the residue definition was set provisionally as sum 1,4-dimethylnaphthalene and M23 (free and conjugated) for both, monitoring and risk assessment. Data gaps were identified for a metabolism study in pig or rat, for standard hydrolysis studies, for processing studies and for animal feeding studies. Pending the submission of the requested data, a provisional chronic consumer risk assessment was conducted resulting in an IEDI value of 40 % of the ADI.

The data available on environmental fate and behaviour were sufficient to carry out the required environmental exposure assessments at EU level for the representative use assessed.

A high risk to aquatic organisms and fish-eating mammals (long-term) was concluded. A data gap was also identified for information to address the long-term risk to fish-eating birds. A low risk was concluded for bees, non-target arthropods, earthworms, soil micro organisms, non-target plants and biological methods of sewage treatment.

1,4-dimethylnaphthalene, peer review, risk assessment, pesticide, plant growth regulator
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