By Date


  • 29-July-2016

    English

    Test No. 473: In Vitro Mammalian Chromosomal Aberration Test

    The purpose of the in vitro chromosome aberration test is to identify agents that cause structural chromosome aberrations in cultured mammalian somatic cells. Structural aberrations may be of two types: chromosome or chromatid.

    The in vitro chromosome aberration test may employ cultures of established cell lines, cell strains or primary cell cultures. Cell cultures are exposed to the test substance (liquid or solid) both with and without metabolic activation during about 1.5 normal cell cycle lengths. At least three analysable concentrations of the test substance should be used. At each concentration duplicate cultures should normally be used. At predetermined intervals after exposure of cell cultures to the test substance, the cells are treated with a metaphase-arresting substance, harvested, stained. Metaphase cells are analysed microscopically for the presence of chromosome aberrations.

  • 29-July-2016

    English

    Test No. 476: In Vitro Mammalian Cell Gene Mutation Tests using the Hprt and xprt genes

    The in vitro mammalian cell gene mutation test can be used to detect gene mutations induced by chemical substances. In this test, the used genetic endpoints measure mutation at hypoxanthine-guanine phosphoribosyl transferase (HPRT), and at a transgene of xanthineguanine phosphoribosyl transferase (XPRT). The HPRT and XPRT mutation tests detect different spectra of genetic events.

    Cells in suspension or monolayer culture are exposed to, at least four analysable concentrations of the test substance, both with and without metabolic activation, for a suitable period of time. They are subcultured to determine cytotoxicity and to allow phenotypic expression prior to mutant selection. Cytotoxicity is usually determined by measuring the relative cloning efficiency (survival) or relative total growth of the cultures after the treatment period. The treated cultures are maintained in growth medium for a sufficient period of time, characteristic of each selected locus and cell type, to allow near-optimal phenotypic expression of induced mutations. Mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant cells, and in medium without selective agent to determine the cloning efficiency (viability). After a suitable incubation time, colonies are counted.

  • 29-July-2016

    English

    Test No. 475: Mammalian Bone Marrow Chromosomal Aberration Test

    The mammalian in vivo chromosome aberration test is used for the detection of structural chromosome aberrations induced by test compounds in bone marrow cells of animals, usually rodents (rats, mice and Chinese hamsters). Structural chromosome aberrations may be of two types: chromosome or chromatid.

    Animals are exposed to the test substance (liquid or solid) by an appropriate route of exposure (usually by gavage using a stomach tube or a suitable intubation cannula, or by intraperitoneal injection) and are sacrificed at appropriate times after treatment. Prior to sacrifice, animals are treated with a metaphase-arresting agent. Chromosome preparations are then made from the bone marrow cells and stained, and metaphase cells are analysed for chromosome aberrations. Each treated and control group must include at least 5 analysable animals per sex. The limit dose is 2000 mg/kg/body weight/day for treatment up to 14 days, and 1000 mg/kg/body weight/day for treatment longer than 14 days.

  • 29-July-2016

    English

    Test No. 490: In Vitro Mammalian Cell Gene Mutation Tests Using the Thymidine Kinase Gene

    The in vitro mammalian cell gene mutation test can be used to detect gene mutations induced by chemical substances. This TG includes two distinct in vitro mammalian gene mutation assays requiring two specific tk heterozygous cells lines: L5178Y tk+/-3.7.2C cells for the mouse lymphoma assay (MLA) and TK6 tk+/- cells for the TK6 assay. Genetic events detected using the tk locus include both gene mutations and chromosomal events.

    Cells in suspension or monolayer culture are exposed to, at least four analysable concentrations of the test substance, both with and without metabolic activation, for a suitable period of time. They are subcultured to determine cytotoxicity and to allow phenotypic expression prior to mutant selection. Cytotoxicity is usually determined by measuring the relative cloning efficiency (survival) or relative total growth of the cultures after the treatment period. The treated cultures are maintained in growth medium for a sufficient period of time, characteristic of each selected locus and cell type, to allow near-optimal phenotypic expression of induced mutations. Mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant cells, and in medium without selective agent to determine the cloning efficiency (viability). After a suitable incubation time, colonies are counted.

  • 29-July-2016

    English

    Test No. 431: In vitro skin corrosion: reconstructed human epidermis (RHE) test method

    The test described in this Test Guideline allows the identification of corrosive chemical substances and mixtures and it enables the identification of non-corrosive substances and mixtures when supported by a weight of evidence determination using other existing information. The test protocol may also provide an indication of the distinction between severe and less severe skin corrosives. This Test Guideline does not require the use of live animals or animal tissue for the assessment of skin corrosivity.

    The test material (solid or liquid) is applied uniformly and topically to a three-dimensional human skin model, comprising at least a reconstructed epidermis with a functional stratum corneum. Two tissue replicates are used for each treatment (exposure time), and for controls. Corrosive materials are identified by their ability to produce a decrease in cell viability below defined threshold levels at specified exposure periods. Coloured chemicals can also be tested by used of an HPLC procedure. The principle of the human skin model assay is based on the hypothesis that corrosive chemicals are able to penetrate the stratum corneum by diffusion or erosion, and are cytotoxic to the underlying cell layers.

  • 29-July-2016

    English

    Test No. 243: Lymnaea stagnalis Reproduction Test

    This Test Guideline is designed to assess effects of prolonged exposure to chemicals on the reproduction and survival of the hermaphrodite freshwater snail Lymnaea stagnalis (the Great Pond Snail). Reproducing adults of L. stagnalis are exposed to a concentration range of the test chemical and monitored for 28 days for their survival and reproduction (number of egg clutches). As additional information, the number of eggs per clutch may also be determined. Adult shell length increase may also be measured. The toxic effect of the test chemical on the cumulated number of clutches produced per individual-day is expressed as ECx by fitting an appropriate regression model to the data in order to estimate the concentration that would cause x% reduction in the reproductive output. Alternatively, the toxic effect of the test chemical can be expressed as the No Observed Effect Concentration and Lowest Observed Effect Concentration (NOEC/LOEC) values. Both ECx and NOEC/LOEC can be determined from a single study.

  • 29-July-2016

    English

    Test No. 483: Mammalian Spermatogonial Chromosomal Aberration Test

    This test measures structural chromosomal aberrations (both chromosome- and chromatid-type) in dividing spermatogonial germ cells and is, therefore, expected to be predictive of induction of heritable mutations in these germ cells. The purpose of the in vivo mammalian spermatogonial chromosomal aberration test is to identify those chemicals that cause structural chromosomal aberrations in mammalian spermatogonial cells (1) (2) (3). In addition, this test is relevant to assessing genetoxicity because, although they may vary among species, factors of in vivo metabolism, pharmacokinetics and DNA-repair processes are active and contribute to the response.

    The original Test Guideline 483 was adopted in 1997. This modified version of the Test Guideline reflects many years of experience with this assay and the potential for integrating or combining this test with other toxicity or genotoxicity studies.

  • 29-July-2016

    English

    Test No. 226: Predatory mite (Hypoaspis (Geolaelaps) aculeifer) reproduction test in soil

    This Test Guideline describes a method to assess the effects of chemical substances in soil on the reproductive output of the soil mite species Hypoaspis (Geolaelaps) aculeifer Canestrini (Acari: Laelapidae). It can be used for water soluble or insoluble substances, but not with volatile substances.

    Adult females of similar age are exposed to a range of concentrations of the test substance mixed into 20 g dry mass of artificial soil 28-35 days after the start of the egg laying period. Depending on the endpoint (ECx, NOEC or both), five to twelve concentrations should be tested. At least two to four replicates for each test concentrations and six to eight control replicates, of 10 animals each, are recommended. At 20¡ãC, the test lasts 14 days after introducing the females, which usually allows the control offspring to reach the deutonymph stage. The number of surviving females (mortality ¡Ü 20% for a valid test) and the number of juveniles per test vessel (at least 50 for a valid test) are determined. The fecundity of the mites exposed to the test substance is compared to that of controls in order to determine the ECx (e.g. EC10, EC50) or the No Observed Effect Concentration (NOEC). Any observed differences between the behaviour and the morphology of the mites in the control and the treated vessels should be recorded.

  • 27-June-2016

    English

    Draft documents for public comments

    This page contains a list of the Guidelines for the Testing of Chemicals.

    Related Documents
  • 31-May-2016

    English

    German database Information system für gefährliche Stoffe IGS

    German database Information system für gefährliche Stoffe IGS is now linked to eChemPortal. The IGS provides public access to a variety of information on chemical and microbiological substances mostly in German. The focus is on regulatory information reflecting German and European, as well as Swiss, US and selected other legislation and assessments. Beside this, information on substance data and emergency procedures is available.

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