{
  "url": "https://openlegislation.uk/eu-regulation-2009-761/annex-VI/division-1/division-1.2",
  "json_url": "https://openlegislation.uk/eu-regulation-2009-761/annex-VI/division-1/division-1.2.json",
  "legislation": "eur/2009/761",
  "legislation_title": "Commission Regulation (EC) No 761/2009 of 23 July 2009 amending, for the purpose of its adaptation to technical progress, Regulation (EC) No 440/2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2009-761",
  "path": "annex/VI/division/1/division/1.2",
  "kind": "division",
  "number": "1.2",
  "heading": "DEFINITIONS",
  "text": "The following definitions and abbreviations are used for the purposes of this Testing Method:\nBiomass: is the dry weight of living matter present in a population. In this test, surrogates for biomass, such as frond counts or frond area, are typically measured and the use of the term ‘biomass’ thus refers to these surrogate measures as well.\nChlorosis: is the yellowing of frond tissue.\nClone: is an organism or cell arisen from a single individual by asexual reproduction. Individuals from the same clone are, therefore, genetically identical.\nColony: means an aggregate of mother and daughter fronds (usually 2 to 4) attached to each other. Sometimes referred to as a plant.\nECx : is the concentration of the test substance dissolved in test medium that results in an x % (e.g. 50 %) reduction in growth of Lemna within a stated exposure period (to be mentioned explicitly if deviating from full or normal test duration). To unambiguously denote an EC value deriving from growth rate or yield, the symbol ‘ErC’ is used for growth rate and ‘EyC’ is used for yield, followed by the measurement variable used, e.g. ErC (frond number).\nFlow-through: is a test in which the test solutions are replaced continuously.\nFrond: is an individual/single ‘leaf-like’ structure of a duckweed plant. It is the smallest unit, i.e. individual, capable of reproduction.\nGibbosity: means fronds exhibiting a humped or swollen appearance.\nGrowth: is an increase in the measurement variable, e.g. frond number, dry weight, wet weight or frond area, over the test period.\nGrowth rate (average specific growth rate): is the logarithmic increase in biomass during the exposure period.\nLowest Observed Effect Concentration (LOEC): is the lowest tested concentration at which the substance is observed to have a statistically significant reducing effect on growth (at p < 0,05) when compared with the control, within a given exposure time. However, all test concentrations above the LOEC must have a harmful effect equal to or greater than those observed at the LOEC. When these two conditions cannot be satisfied, a full explanation must be given for how the LOEC (and hence the NOEC) has been selected.\nMeasurement variables: are any type of variables which are measured to express the test endpoint using one ore more different response variables. In this method frond number, frond area, fresh weight and dry weight are measurement variables.\nMonoculture: is a culture with one plant species.\nNecrosis: is dead (i.e. white or water-soaked) frond tissue.\nNo Observed Effect Concentration (NOEC): is the test concentration immediately below the LOEC.\nPhenotype: is the observable characteristics of an organism determined by the interaction of its genes with its environment.\nResponse variables: are variables for the estimation of toxicity derived from any measured variables describing biomass by different methods of calculation. For this method, growth rates and yield are response variables derived from measurement variables like frond number, frond area, fresh weight or dry weight.\nSemi-static (renewal) test: is a test in which the test solution is periodically replaced at specific intervals during the test.\nStatic test: is a test method without renewal of the test solution during the test.\nTest endpoint: describes the general factor that will be changed by the test chemical relative to the control as aim of the test. In this method the test endpoint is inhibition of growth, which may be expressed by different response variables which are based on one or more measurement variables.\nTest medium: is the complete synthetic growth medium on which test plants grow when exposed to the test substance. The test substance will normally be dissolved in the test medium.\nYield: is the value of a measurement variable to express biomass at the end of the exposure period minus the measurement variable at the start of the exposure period.",
  "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/2009/761/annex/VI/division/1/division/1.2",
    "retrieved_at": "2026-11-01T14:51:19.625001+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."
}