Diclazuril (Clinacox 0.5 %) renewed until 2036 — the environmental assessment was closed by new soil studies under OECD 106 and 307: mean DT50 of 247 days at 20 °C, Koc of 8356 l/kg
Commission Implementing Regulation (EU) 2026/2086 of 18 September 2026, published on 21 September, renews until 11 October 2036 the authorisation of the coccidiostat Clinacox 0.5 % (Elanco GmbH) for chickens for fattening and chickens reared for laying (up to 16 weeks) — 1 mg diclazuril/kg feed. In 2024 EFSA could not assess safety for the environment because of data gaps; a new 2026 opinion found no risk.
- Soil sorption was studied under OECD Test Guideline 106 in five mineral soils with pH of about 4–7.5; concentrations in the aqueous phases and soil extracts were measured by LC-MS/MS. Kd ranged from 47.96 to 1058.84 l/kg and the geometric mean Koc was 8356 l/kg, indicating strong sorption and low mobility.
- Aerobic transformation of [14C]diclazuril (OECD 307) in four soils at 20 °C gave DT50 values from 140 to 349 days, a geometric mean of 247 days; normalised to 12 °C — 524 days. No degradation products above 5 % of applied radioactivity were found, and the mass balance at the end of the study was 95.7 %.
- Because of the persistence, EFSA refined the concentrations for accumulation: PEC soil 39 µg/kg (plateau), groundwater 0.06 µg/l, surface water 0.02 µg/l, sediment 16 µg/kg. In a test on eight plant species (OECD 208, 62.5–1000 mg/kg) there were no effects — NOEC > 1000 mg/kg; recovery of the substance from soil was 94–110 %.
- Control methods: diclazuril in the additive — HPLC-UV, in premixtures — HPLC-UV under Regulation (EC) No 152/2009, in feed — HPLC-UV under 152/2009 or LC-MS/MS under EN 17299. The holder monitors Eimeria spp. resistance; preparations and premixtures labelled before 11 April 2027 and feed labelled before 11 October 2027 may be used until stocks are exhausted.