Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the Maximum Residue Limits for monensin sodium for chickens and turkeys for fattening

Elancoban® and Coxidin® are feed additives belonging to the category of coccidiostats which both contain monensin sodium as active substance. The setting of two different MRLs for the same species and tissues is not desirable. EFSA has been requested by the European Commission to take the necessary steps to suggest a single MRL. To establish an MRL, the marker residue indicating the total tissue residue levels must be defined. The ratios of the marker residue/total residues should be established at all time points during the depletion studies. In the case of Elancoban® and Coxidin®, monensin is considered as marker residue. Alternatives are not available. After a three-day withdrawal, the time considered for total residues not to reach the ADI, monensin concentration dropped below the LOQ of the most sensitive methods in all tissues. The ratio marker residue to total residue for the withdrawal time of three days could therefore not be calculated. Establishing an MRL by the classical route is consequently not possible. The FEEDAP Panel proposes provisional MRLs. The magnitude is orienting toward the authorised withdrawal time of three days, the most sensitive analytical methods (limit of quantification 0.0025 mg kg-1) and the residue data available for chickens for fattening. For liver, kidney and muscle tissue, a provisional MRL of 0.008 mg kg-1 tissue is proposed; for skin/fat, of 0.025 mg kg-1 tissue. With ratios of marker residue to total residue deduced from zero-withdrawal time, calculations using the provisional MRLs proposed show that the worst-case exposure of the consumer to total residue will be within the ADI. Due to the similarity in metabolism of monensin in chickens for fattening and turkeys for fattening, the same MRLs as those proposed for chickens can be applied for turkeys. The scarcity of turkey data prevents a separate MRL calculation and stresses, in addition, the fact that the MRLs proposed are provisional.