Reasoned opinion on the review of the existing maximum residue levels (MRLs) for metosulam according to Article 12 of Regulation (EC) No 396/2005


European Food Safety Authority
EFSA Journal
EFSA Journal 2015;13(1):3983 [33 pp.].

EFSA wishes to thank the rapporteur Member State, France, for the preparatory work on this scientific output.

Reasoned Opinion
On request from
Question Number
No EFSA-Q-2009-00063
22 December 2014
19 January 2015
European Food Safety Authority (EFSA), Parma, Italy
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According to Article 12 of Regulation (EC) No 396/2005, the European Food Safety Authority (EFSA) has reviewed the Maximum Residue Levels (MRLs) currently established at European level for the pesticide active substance metosulam. In order to assess the occurrence of metosulamresidues in plants, processed commodities, rotational crops and livestock, EFSA considered the conclusions derived in the framework of Directive 91/414/EEC as well as the European authorisations reported by Member States (incl. the supporting residues data). Based on the assessment of the available data, MRL proposals were derived and a consumer risk assessment was carried out. Although no apparent risk to consumers was identified, some information required by the regulatory framework was found to be missing. Hence, the consumer risk assessment is considered indicative only and some MRL proposals derived by EFSA still require further consideration by risk managers. 


Metosulam was included in Annex I to Directive 91/414/EEC on 01 May 2011, which is after the entry into force of Regulation (EC) No 396/2005 on 2 September 2008. EFSA is therefore required to provide a reasoned opinion on the review of the existing MRLs for that active substance in compliance with Article 12(1) of the aforementioned regulation. In order to collect the relevant pesticide residues data, EFSA asked France, as the designated rapporteur Member State (RMS), to complete the Pesticide Residues Overview File (PROFile) and to prepare a supporting evaluation report. The requested information was submitted to EFSA on 24 March 2014 and, after having considered several comments made by EFSA, the RMS provided on 23 April 2014 a revised PROFile.

Based on the conclusions derived by EFSA in the framework of Directive 91/414/EEC and the additional information provided by the RMS, EFSA issued on 27 September 2014 a draft reasoned opinion that was circulated to Member States’ experts for consultation. Comments received by 31 October 2014 were considered in the finalisation of this reasoned opinion. The following conclusions are derived.

The toxicological profile of metosulam was evaluated in the framework of Directive 91/414/EEC, which resulted in an ADI and an ARfD being established at 0.05 mg/kg bw per d and 0.25 mg/kg bw, respectively.

Metabolism of metosulam was investigated for foliar application on wheat and soil application on potatoes. Radioactivity in the harvested crop was extremely low and there was little evidence of uptake of metosulam from the soil or translocation into the edible parts of the plants. A representative metabolism study for fruits and fruiting vegetables is however still required. Meanwhile, the residue definition proposed for enforcement and risk assessment (applicable to root and tuber vegetables and cereals and, tentatively, to fruits and fruiting vegetables) is metosulam. Validated analytical methods for enforcement of the proposed residue definition are available.

Regarding the magnitude of residues, the available residues data are considered sufficient to derive MRL proposals as well as risk assessment values for all crops supported in the framework of this review, except for pome fruit, stone fruit and berries & small fruit, where only a tentative MRL could be derived. MRL proposals for potatoes and sweet corn are also considered tentative because storage stability of metosulam in high water content commodities was not investigated.

As quantifiable residues of metosulam are not expected in the treated crops and the chronic exposure does not exceed 10 % of the ADI there is no need to investigate the effect of industrial and/or household processing. Specific processing factors for enforcement of processed commodities are therefore not proposed.

Occurrence of metosulam residues in rotational crops was investigated during the peer review of metosulam. It was concluded that the primary crop metabolism studies, conducted with applications mainly directed to the soil, demonstrate that parent and soil metabolites were not taken up by wheat or potato plants and that significant residues in rotational crops are not expected. These conclusions also apply to the GAPs supported in the framework of this review.

Based on the uses reported by the RMS the calculated dietary burdens for dairy and meat ruminants were found to exceed the trigger value of 0.1 mg/kg DM. The calculations are likely to be overestimated as the use on maize silage, where residues are expected to be well below the LOQ, was included in the livestock dietary burden calculation at 0.05 mg/kg. Moreover a metabolism study in goats, conducted at a dose rate corresponding to approximately 36 times the exposure of meat ruminants, demonstrates that TRR in organs and milk never exceeded 0.17 mg eq/kg. In addition to this the feeding study with lactating cows confirms that no residues above the relevant LOQ are expected in edible or non-edible ruminant tissues, or in milk. EFSA therefore concludes that there is no need to define a residue in commodities of animal origin and MRLs are not required.

Both chronic and acute consumer exposure resulting from the authorised uses reported in the framework of this review were calculated using revision 2 of the EFSA PRIMo. The highest chronic exposure represented 0.5 % of ADI (German children) and the highest acute exposure amounted to 0.6 % of the ARfD (potatoes).

Based on the above assessment, EFSA does not recommend inclusion of this active substance in Annex IV to Regulation (EC) No 396/2005. MRL recommendations were derived in compliance with the decision tree reported in Appendix D of the reasoned opinion (see summary table). All MRL values listed as ‘Recommended’ in the table are sufficiently supported by data and are therefore proposed for inclusion in Annex II to the Regulation. The remaining MRL values listed in the table are not recommended for inclusion in Annex II because they require further consideration by risk managers (see summary table footnotes for details). In particular, some tentative MRLs need to be confirmed by the following data:

  • a representative study investigating primary crop metabolism in the fruits and fruiting vegetables group (this data gap does not apply to sweet corn which is covered by cereals);
  • information on the timing of application (PHI or growth stage at last treatment) for the northern outdoor GAPs on pome fruit, stone fruit, berries & small fruit;
  • residues trials supporting the northern GAPs for pome fruit, stone fruit, berries & small fruit are required to confirm the tentative MRL and risk assessment values proposed at the LOQ;
  • a storage stability study for metosulam in high water content commodities;
  • storage conditions of residue trial samples of potatoes for the trials reported in the PROFile.

Minor deficiencies were also identified in the assessment but these deficiencies are not expected to impact either on the validity of the MRLs derived or on the national authorisations. The following data are therefore considered desirable but not essential:

  • residue trials supporting the northern outdoor GAPs on maize forage carried out with analytical methods achieving an LOQ of 0.01 mg/kg.
metosulam, MRL review, Regulation (EC) No 396/2005, consumer risk assessment, triazolopyrimidine, sulfonanilide, herbicide
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