Acidic herbicide in focus: haloxyfop
New reduced limits from August 2024
Apr 2024. On 19 August 2024, new maximum residue levels (MRLs) for haloxyfop-P will enter into force in accordance with Regulation (EU) 2024/398. With the withdrawal of the authorisation, the current MRLs will be reduced to the lower limit of analytical determination. We give you an overview of the legal changes for this acidic herbicide and explain how we can support you with the analysis.
Legal changes
Haloxyfop-P had been approved in the EU as a herbicide for the control of monocotyledonous weeds since 1 January 2011. In accordance with Implementing Regulation (EU) No. 2020/1643, the approval of the active substance was withdrawn retroactively to 31 December 2020 as the application for renewal of the approval of the active substance was withdrawn by the applicant[1].
On 19 August 2024, new MRLs for haloxyfop-P will enter into force in accordance with Regulation (EU) 2024/398. The new MRLs will be lowered to the lower limit of analytical determination, which is set at 0.01 mg/kg for most products and 0.05 mg/kg for products with particularly high levels of essential oils (e.g. spices, coffee, tea and herbal tea). Specific MRLs exist for only a few products such as sunflower seeds, linseed and rapeseed as well as soybeans and onions, for some of which applications for import tolerances have been requested by third countries.
The analytical limit of determination for haloxyfop-P has been reduced to 0.002 mg/kg for milk from all animal species. This particularly strict product-specific value is justified by the fact that, according to the European Food Safety Authority (EFSA), milk is the major contributor to chronic exposure of the population [2].
Analytical testing
The Eurofins Food & Feed Tesing laboratories in Germany offer you pesticide screening packages that routinely include haloxyfop and some of its derivatives as analytical parameters in all liquid chromatography (LC) and some gas chromatography (GC) tests. In this way, haloxyfop can be quickly and cost-effectively included alongside a wide range of pesticides.
To ensure that you meet the complete residue definition of haloxyfop in accordance with EU Regulation 396/2005 on maximum residue levels of plant protection products in food and feed, we can analyse your products on request using a group-specific analysis method for phenoxyalkanecarboxylic acids. This method can also be used to detect esters, salts and conjugates of haloxyfop.
Our customised pesticide screening packages are based on the product categories of the SANTE document 11312/2012 on analytical quality control for pesticide residue analysis in food and feed[3]. This product specific approach and the continuous development and optimisation of our analytical methods allow us to offer the new requirements for the determination of haloxyfop in milk even before the new MRLs for haloxyfop come into force.
How haloxyfop works as a herbicide
Haloxyfop and its derivatives are acidic herbicides that are used as growth inhibitors, among other things. They belong to the substance class of phenoxyalkanecarboxylic acids. It is a systemic active ingredient that is taken up mainly by the aerial parts of the plant, but also to a significant extent by the roots[4].
It inhibits the enzyme acetyl-CoA carboxylase in monocotyledonous plants (monocots), which make up the majority of weeds, causing them to die. In contrast, dicotyledonous plants, which include many arable crops such as oilseed rape, sugar beet and potatoes, are not affected by haloxyfop and other phenoxyalkanoic acid herbicides.
Although wheat, rye and other cereals are monocotyledonous, phenoxyalkanecarboxylic acids can also be used in cereal crops if so-called "safeners" are used at the same time. These co-formulants accelerate the detoxification process in the crop, protecting it from the acidic herbicides[4, 5].
Toxicology and uptake
Haloxyfop, like other phenoxyalkanecarboxylic acid herbicides, has a low toxicity to mammals. Therefore, the EFSA has derived an Acute Reference Dose (ARfD) of 0.075 mg/kg body weight per day for short-term exposure and an Acceptable Daily Intake (ADI) of 0.00065 mg/kg body weight per day for chronic exposure.
In addition to the direct intake of haloxyfop through foods that have been actively treated with the active substance during production, the main source of exposure for consumers is cow's milk.
Although haloxyfop residues are mainly excreted in the urine, non-negligible amounts are also excreted in the milk of lactating animals. Thus, forage grasses contaminated with haloxyfop can lead to additional haloxyfop exposure of consumers[6].
Please contact us
Do you have questions about the analysis of haloxyfop or other phenoxyalkanecarboxylic acids? Contact your personal account manager or get in touch with our experts directly.
Relevante Quellen
[1] In German: BvL Bund: Widerruf der Zulassung des Pflanzenschutzmittels GALLANT SUPER rückwirkend zum 31. Dezember 2020 (call date: 19 April 2024);
Commission Implementing Regulation (EU) 2020/1643 as regards the approval periods of the active substances calcium phosphide, denathonium benzoate, haloxyfop-P, imidacloprid, pencycuron and zeta-cypermethrin
[2] Commission Regulation (EU) 2024/398 as regards maximum residue levels for haloxyfop in or on certain products
[3] Document SANTE 11312/2021 v2 "Analytical quality control and method validation procedures for pesticide residue analysis in food and feed"
[4] In German: PSM-Zulassungsbericht (Registration Report) GALLANT SUPER 034286 des Bundesamt für Verbraucherschutz und Lebensmittelsicherheit, Stand 2012-03-12
[5] In German: top agrar online, 04.08.2023 | Pflanzenschutzmittel: So wirken Herbizide in Pflanzen (call date: 19 April 2024)
[6] EFSA: Conclusion on the peer review of the pesticide risk assessment of the active substance haloxyfop-P (haloxyfop-R) on request from the European Commission. EFSA Journal 2009; 7 (11): 1348 [102 pp]
