(Also known as: imazamethapyr; imazameth; CL 263222)
Imazapic is a selective pre- and post-emergent herbicide without EU regulatory approval for use. It has a high aqueous solubility, is volatile and, based on its chemical properties, is moderately mobile and may leach to groundwater. It is may be persistent in soil systems but usually degrades quickly in aquatic systems via photolysis. It has a low mammalian toxicity and has a high potential for bioaccumulation. It has a low level of toxicity to birds but is more toxic to aquatic life and honey bees.
The following alerts are based on the data in the tables below. An absence of an alert does not imply the substance has no implications for human health, biodiversity or the environment but just that we do not have the data to form a judgement.
Environmental fate High alert: Persistent; GUS: High leachability
Ecotoxicity Moderate alert: Fish chronic ecotoxicity: Moderate
Human health Low alert
A selective herbicide used for both the pre- and post-emergent control of some grasses and broad-leaved weeds.
Example pests controlled
Annual and perennial grasses and some broad-leaved weeds
Peanuts; Rangeland; Non-cropped areas
Efficacy & activity
Introduction & key dates
UK regulatory status
UK COPR regulatory status
Date COPR inclusion expires
UK LERAP status
No UK approval for use
EC Regulation 1107/2009 (repealing 91/414)
EC Regulation 1107/2009 status
Date EC 1107/2009 inclusion expires
EU Candidate for substitution (CfS)
Listed in EU database
Approved for use (✓) under EC 1107/2009 in the following EU Member States
Also used in
Also used in
Imazapic is a molecule with one chiral centre. The technical material is an isomeric mixture.
Selective, systemic, contact and residual activity, inhibiting the production of amino acids necessary for cell division and growth. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS.
Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242