-Abstract-

In compliance with Article 43 of Regulation (EC) No 396/2005, EFSA received from the European Commission a mandate to update its previous review of the existing maximum residue levels (MRLs) for thiabendazole on the basis of the new toxicological reference values as indicated in the EFSA conclusion on the peer review of thiabendazole under Regulation (EU) No 1141/2010. Based on the assessment of the available data, MRL proposals were derived and a consumer risk assessment was carried out. Some information required by the regulatory framework was missing and a possible acute risk to consumers was identified. Hence, the consumer risk assessment is considered indicative only, all MRL proposals derived by EFSA still require further consideration by risk managers and measures for reduction of the consumer exposure will also need to be considered.

-Summary-

Thiabendazole was included in Annex I to Directive 91/414/EEC on 1 January 2002 by Commission Directive 2001/21/EC, and has been deemed to be approved under Regulation (EC) No 1107/2009, in accordance with Commission Implementing Regulation (EU) No 540/2011. The European Food Safety Authority (EFSA) published a reasoned opinion on the review of the existing maximum residue levels (MRLs) for thiabendazole in compliance with Article 12(2) of Regulation (EC) No 396/2005 on 4 July 2014.

Thiabendazole was subsequently evaluated for renewal of approval in the framework of Commission Regulation (EC) No 1107/2009 and the toxicological reference values for the substance were lowered.

EFSA therefore received on 23 December 2015, in accordance with Article 43 of Regulation (EC) No 396/2005, a mandate from the European Commission to revise the assessment of thiabendazole taking into consideration the new toxicological reference values as noted by the Standing Committee on Plants, Animals, Food and Feed (SCPAFF). For this assessment, EFSA mainly relied on its previous reasoned opinion for thiabendazole, its recent conclusion on the peer review of thiabendazole and on the Renewal Assessment Report (RAR) for thiabendazole prepared by Spain in the framework of Commission Regulation (EU) No 1141/2010. Furthermore, EFSA asked Member States to provide fall-back data for the uses for which an acute concern was identified. The following conclusions were derived.

Primary crop metabolism of thiabendazole was investigated in three crop groups upon foliar treatment and in fruit crops upon post-harvest applications. In cereals upon seed treatment, no identification of residues was attempted as total residues were too low. Furthermore, rotational crop metabolism was investigated in three different crop groups at three different plant-back intervals (PBIs). Based on these studies, the residue for enforcement and risk assessment in all plant commodities having received a post-harvest treatment is defined as thiabendazole only. Validated analytical methods for enforcement of the proposed residue definitions are available. For crops having received a treatment prior to their harvest, and for rotational crops, it is tentatively proposed to include benzimidazole and its conjugates in the residue definition for risk assessment (mainly relevant for the authorised uses on seed potatoes and chicory roots). The toxicological profile of benzimidazole currently being unknown, this compound may require a separate risk assessment compared to the parent compound.

Nature of residues in processed commodities was also investigated but a detailed and reproducible evaluation of this study is still required to judge the validity of the data. Applicability of the plant residue definition to processed plant commodities is therefore still pending confirmation.

The magnitude of thiabendazole was investigated in primary crops, rotational crops and processed commodities. The magnitude of benzimidazole in rotational crops was also investigated but the efficiency of the analytical method to cover conjugated residues still needs to be demonstrated and the southern trial results for the PBI of 365 days are still required. Depending on the outcome of the toxicological assessment of benzimidazole, further trials analysing for total benzimidazole may be required to support the primary crop uses in potatoes and chicory roots. Meanwhile, available data were still considered sufficient to derive tentative MRL and risk assessment values for parent thiabendazole in the plant commodities under consideration. New residue trials on apples also allowed EFSA to derive a specific variability factor of 1.6 for the post-harvest treatment of apples and pears with thiabendazole. Reliable processing factors (PFs) were only derived for the peeling of bananas and citrus fruits. Other PFs derived in the framework of this review are considered tentative.

Livestock dietary burdens were found to exceed the trigger value of 0.1 mg/kg dry matter (DM) for all groups of livestock. Based on the available metabolism studies in lactating ruminants and poultry the residue for enforcement and risk assessment was defined in all tissues and eggs as the sum of thiabendazole and 5-hydroxythiabendazole, expressed as thiabendazole. In milk, the residue for both enforcement and risk assessment was defined as the sum of thiabendazole, 5-hydroxythiabendazole and its sulfate conjugate, expressed as thiabendazole. For risk assessment purposes, it is proposed to also include benzimidazole in the residue definition for animal commodities. However, as further information regarding the residue situation and the toxicological properties of benzimidazole is still required, this metabolite may require a separate risk assessment compared to the parent compound. Validated analytical methods for the proposed residue definition are however not available, and an analytical standard for 5-hydroxythiabendazole O-sulfate conjugate is currently not commercially available.

Livestock feeding studies in ruminants and poultry were also reported. Although storage conditions of the study samples should still be reported and further investigation on the occurrence of benzimidazole is still required, available data still allowed EFSA to estimate tentative MRL and risk assessment values in all commodities of animal origin (only for thiabendazole, 5-hydroxythiabendazole and the sulfate conjugate).

Chronic and acute consumer exposure resulting from the authorised uses reported in the framework of this review was calculated using revision 2 of the EFSA Pesticide Residues Intake Model (PRIMo). For potatoes and mangoes, an exceedance of the acute reference dose (ARfD) was identified representing 1,845% and 771% of the ARfD, respectively. Excluding the authorisations on mangoes and considering a fall-back good agricultural practice (GAP) for potatoes (seed treatment), the highest chronic exposure represented 28% of the acceptable daily intake (ADI; German child) and the highest acute exposure amounted to 85% of the ARfD (apples).

Apart from the MRLs evaluated in the framework of this review, internationally recommended codex maximum residue limits (CXLs) have also been established for thiabendazole. Additional calculations of the consumer exposure, considering these CXLs, were therefore carried out and exceedances of the ARfD were identified for the existing CXLs in potatoes (1,691%), cultivated fungi (439%) and mangoes (299%). Excluding these CXLs from the calculation, the highest chronic exposure represented 29% of the ADI (German child) and the highest acute exposure amounted to 85% of the ARfD (apples).

Furthermore, veterinary MRLs of 0.1 mg/kg are currently established for muscle, fat, liver, kidney and milk originating from both bovine and caprine species. All veterinary MRLs are covered by the European Union (EU) MRL proposals or by the existing CXLs considered in the previous exposure scenarios, except for goat muscle and goat fat where the veterinary MRL is higher. Nevertheless, when including these two veterinary MRLs in the calculations, the highest chronic and acute exposures remain unchanged.

As further information regarding the residue situation and the toxicological properties of benzimidazole is still required, EFSA was not able to include this metabolite in the exposure calculations but it is estimated that, in order to exceed the ARfD in eggs (most critical commodity currently identified regarding the exposure to benzimidazole), the toxicological potency of benzimidazole would need to be approximately eight times higher compared to the toxicological potency of the parent compound.

http://www.efsa.europa.eu/en/efsajournal/pub/4516