{
  "url": "https://openlegislation.uk/eu-directive-2004-73/annex-2H/division-B.43/division-1/division-1.4/division-1.4.1",
  "json_url": "https://openlegislation.uk/eu-directive-2004-73/annex-2H/division-B.43/division-1/division-1.4/division-1.4.1.json",
  "legislation": "eudr/2004/73",
  "legislation_title": "Commission Directive 2004/73/EC of 29 April 2004 adapting to technical progress for the twenty-ninth time Council Directive 67/548/EEC on the approximation of the laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-directive-2004-73",
  "path": "annex/2H/division/B.43/division/1/division/1.4/division/1.4.1",
  "kind": "division",
  "number": "1.4.1",
  "heading": "Selection of animal species",
  "text": "The preferred rodent species is the rat, although other rodent species, with justification, may be used. Commonly used laboratory strains of young adult healthy animals should be employed. The females should be nulliparous and non-pregnant. Dosing should normally begin as soon as possible after weaning, preferably not later than when animals are six weeks, and, in any case, before the animals are nine weeks age. However, when this study is combined with other studies this age requirement may need adjustment. At the commencement of the study the weight variation of animals used should not exceed ± 20 % of the mean weight of each sex. Where a repeated dose study of short duration is conducted as a preliminary to a long term study, animals from the same strain and source should be used in both studies.",
  "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/eudr/2004/73/annex/2H/division/B.43/division/1/division/1.4/division/1.4.1",
    "retrieved_at": "2026-11-01T15:22:47.605967+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."
}