Bixlozone — new herbicide approved until 21 April 2036: purity ≥ 960 g/kg, TBAB impurity up to 2 g/kg; EFSA — LC-MS/MS with an LOQ of 0.01 mg/kg in food and feed, metabolite 2,4-dichlorobenzoic acid in groundwater up to 2.88 µg/L, no data on the effect of water chlorination
Commission Implementing Regulation (EU) 2026/747, published on 1 April 2026, approves the new active substance bixlozone (herbicide, applicant FMC International Switzerland Sarl, rapporteur Member State the Netherlands) from 21 April 2026 to 21 April 2036. It is based on the EFSA conclusion of 2 October 2024 on soil applications in winter cereals, winter oilseed rape and maize. By 21 April 2028 the applicant must submit confirmatory information — among other things on the specification of commercial production, the toxicity of several metabolites and the effect of water treatment on residues.
- Annex: bixlozone, 2-(2,4-dichlorobenzyl)-4,4-dimethylisoxazolidin-3-one, CAS No 81777-95-9, CIPAC not allocated; purity ≥ 960 g/kg, TBAB impurity (N,N,N-tributylbutan-1-aminium bromide) not more than 2 g/kg in the technical material. Member States must pay attention to co-formulants (Regulation (EU) 2023/574), residues in rotational crops with plant-back intervals, and the protection of aquatic organisms and non-target terrestrial plants.
- Methods (EFSA): bixlozone residues in food and feed of plant origin — LC-MS/MS, LOQ 0.01 mg/kg in each commodity group (data gap: extraction efficiency in high-water commodities); in animal products 5-hydroxy-bixlozone — QuEChERS and LC-MS/MS, LOQ 0.01 mg/kg, conjugates after hydrolysis — 0.005 mg/kg in milk (without independent laboratory validation). Soil 0.005 mg/kg, surface and drinking water 0.1 µg/L, air 0.36 µg/m³, body fluids 0.05 mg/L. A method for TBAB in the formulation is missing.
- Reference values (EFSA): ADI 0.29 mg/kg bw per day, ARfD 0.75 mg/kg bw, AOEL 0.20 and AAOEL 0.53 mg/kg bw per day; oral absorption 70 %. Enforcement residue definition in plants — bixlozone, in animal products — 5-hydroxy-F9600 free and conjugated, expressed as bixlozone. Consumer risk assessment not finalised: data missing on the natural occurrence of 2,2-dimethyl-3-OH-propionic acid (up to 0.3 mg/kg in maize grain) and dimethylmalonic acid and on the toxicity of five metabolites.
- Environment (EFSA): in FOCUS modelling 2,4-dichlorobenzoic acid exceeds 0.1 µg/L in groundwater in most scenarios (up to 2.88 µg/L), but it was considered a metabolite not relevant to health. Data on water ozonation were sufficient, on chlorination not, so the drinking water risk was not fully assessed. High risk to aquatic organisms for all uses except maize; low chronic risk to bees was not demonstrated. Bixlozone does not meet the criteria for an endocrine disruptor.