{
  "url": "https://openlegislation.uk/eu-regulation-2013-283/annex/section-5/division-5.4/division-5.4.2/division-1",
  "json_url": "https://openlegislation.uk/eu-regulation-2013-283/annex/section-5/division-5.4/division-5.4.2/division-1.json",
  "legislation": "eur/2013/283",
  "legislation_title": "Commission Regulation (EU) No 283/2013 of 1 March 2013 setting out the data requirements for active substances, in accordance with Regulation (EC) No 1107/2009 of the European Parliament and of the Council concerning the placing of plant protection products on the market (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2013-283",
  "path": "annex/section/5/division/5.4/division/5.4.2/division/1",
  "kind": "division",
  "number": null,
  "heading": "Circumstances in which required",
  "text": "If all the results of the in vitro studies are negative, at least one in vivo study shall be done with demonstration of exposure to the test tissue (such as cell toxicity or toxicokinetic data), unless valid in vivo micronucleus data are generated within a repeat dose study and the in vivo micronucleus test is the appropriate test to be conducted to address this information requirement.\nA negative result in the first in vivo test in somatic cells shall provide sufficient reassurance for active substances that are negative in the three in vitro tests.\nFor active substances for which an equivocal or a positive test result is obtained in any in vitro test, the nature of additional testing needed shall be considered on a case-by-case basis taking into account all relevant information using the same endpoint as in the in vitro test.\nIf the in vitro mammalian chromosome aberration test or the in vitro micronucleus test is positive for clastogenicity, an in vivo test for clastogenicity using somatic cells such as metaphase analysis in rodent bone marrow or micronucleus test in rodents shall be conducted.\nIf the in vitro micronucleus test for numerical chromosome aberrations on mammalian cells is positive or the in vitro mammalian chromosome test is positive for numerical chromosome changes, an in vivo micronucleus test shall be conducted. In case of positive result in the in vivo micronucleus assay, appropriate staining procedure such as fluorescence in-situ hybridisation (FISH) shall be used to identify an aneugenic and/or clastogenic response.\nIf either of the in vitro gene mutation tests is positive, an in vivo test to investigate the induction of gene mutation shall be conducted, such as the Transgenic Rodent Somatic and Germ Cell Gene Mutation Assay.\nWhen conducting in vivo genotoxicity studies, only relevant exposure routes and methods (such as admixture to diet, drinking water, skin application, inhalation and gavage) shall be used. There shall be convincing evidence that the relevant tissue will be reached by the chosen exposure route and application method. Other exposure techniques (such as intraperitoneal or subcutaneous injection) that are likely to result in abnormal kinetics, distribution and metabolism shall be justified.\nConsideration shall be given to conducting an in vivo test as part of one of the short-term toxicity studies described under point 5.3.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2013/283/annex/section/5/division/5.4/division/5.4.2/division/1",
    "retrieved_at": "2026-11-01T14:48:46.014078+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}