Fluralaner in fish: MRL of 65 µg/kg in muscle and skin, transferred from poultry muscle without residue depletion studies — LC-MS/MS method validated for salmonids in the range 10–200 µg/kg
Commission Implementing Regulation (EU) 2025/1908, published on 25 September 2025, extends the fluralaner entry in Table 1 of the Annex to Regulation (EU) No 37/2010 to all fish: an MRL of 65 µg/kg in muscle and skin in natural proportions, with fluralaner as the marker residue. FAV S.A. applied for salmonids (treatment of juvenile and adult sea lice), and the European Medicines Agency considered extrapolation to all fish appropriate.
- Method: according to CVMP opinion EMA/CVMP/27344/2025 of 12 February 2025, the LC-MS/MS method for muscle and skin of salmonids is validated in the range 10–200 µg/kg in line with Regulation (EU) 2018/782 and guideline VICH GL 49; the EU reference laboratory agreed with this assessment. For other fish the method is “expected” to be applicable, but this was not demonstrated. Residue control should cover muscle with skin.
- The applicant submitted no pharmacokinetic or residue depletion studies in fish. The MRL was transferred from poultry muscle under Article 6(f) of Regulation (EU) 2017/880: the parent compound is the marker residue, and metabolism in fish is simpler than in mammals and poultry, though slower in cold water.
- The ADI is 10 µg/kg bw (600 µg per person) — from a NOEL of 1 mg/kg bw per day in a 52-week study in dogs and a factor of 100; the theoretical daily intake of residues of 360.2 µg is 60 % of the ADI. Proposed dosing: 0.5 mg/kg fish body weight per day in feed for 7 days.
- The poultry entry is unchanged: muscle 65, skin and fat 650, liver 650, kidney 420, eggs 1 300 µg/kg. The CVMP justifies the new use by the resistance of sea lice to several substances in available medicines.