Maleic hydrazide may be used on crops intended for feed: the Commission lifts the requirement to label treated crops and keep livestock away from them; EFSA — the metabolite 3-pyridazinone is not genotoxic, ADI 0.13 mg/kg bw, a separate residue definition in animal commodities and proposed MRLs of up to 3 mg/kg in offal; hydrazine in the technical material ≤ 0.028 mg/kg
Commission Implementing Regulation (EU) 2026/321, published on 13 February 2026, amends the approval conditions of maleic hydrazide (a growth regulator that suppresses sprouting) set at its renewal in 2017. It removes the condition that the label of treated crops must indicate the treatment and include instructions to avoid exposure of livestock — in practice it excluded use on crops for feed. The application was submitted by a task force (Arysta LifeScience Great Britain and Drexel Chemical Company), the rapporteur was Belgium; according to the EFSA conclusions of July 2025 the new data dispelled the concerns about the metabolite 3-pyridazinone.
- Conditions after the amendment: maleic hydrazide, CAS No 123-33-1, CIPAC No 310, 6-hydroxy-2H-pyridazin-3-one, purity ≥ 979 g/kg; the hydrazine impurity must not exceed 0.028 mg/kg in the technical material; approval from 1 November 2017 to 31 October 2032 unchanged. Member States pay particular attention to consumer protection and operator and worker safety (personal protective equipment in the conditions of use). Representative uses: foliar sprays for sprout suppression in onion, shallot, garlic, carrot and potato and control of potato volunteers; the product ‘Fazor’ (600 g/kg as the potassium salt).
- 3-Pyridazinone (EFSA): in 2016 the consumer risk assessment could not be finalised because this metabolite is part of the residue definition in animal commodities and there were no data on its genotoxicity. New in vitro studies excluded mutagenic, clastogenic and aneugenic potential; from a 90-day rat study (LOAEL 267 mg/kg bw per day — increased relative liver weight, hepatocyte vacuolation) an ADI of 0.13 mg/kg bw per day was derived with an overall uncertainty factor of 2000; an ARfD was considered not needed.
- Residues (EFSA): the risk assessment definition in animal commodities (except milk) — maleic hydrazide and separately 3-pyridazinone, in milk — maleic hydrazide with its conjugates and separately 3-pyridazinone; the enforcement definition is unchanged — maleic hydrazide. Dried potato pulp is the main contributor to the livestock dietary burden (default processing factor 38). On the basis of feeding studies in hens and cows EFSA proposes raising the MRLs for animal commodities — from 0.01 mg/kg in muscle to 3 mg/kg in edible offal and kidney.
- Consumer exposure (PRIMo 3.1): the theoretical maximum daily intake of maleic hydrazide with current plant MRLs and proposed animal MRLs — 138 % of the ADI (Portuguese general population); refined with supervised trial medians — 30 % of the ADI (Dutch toddlers). For 3-pyridazinone at most 1 % of the ADI, mainly from cow’s milk (0.92 %). Identity, analytical methods, environmental fate, ecotoxicology and endocrine properties were not reassessed — the 2016 conclusions, including unresolved issues, remain applicable.