By Date


  • 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. 242: Potamopyrgus antipodarum Reproduction Test

    The Potamopyrgus antopodarumon reproduction test is designed to assess potential effects of prolonged exposure to chemicals on reproduction and survival of parthenogenetic lineages of the freshwater mudsnail Potamopyrgus antipodarum. Adult female P. antipodarum are exposed to a concentration range of the test chemical. The test chemical is dispersed into the reconstituted dilution water, added to test beakers, and adult snails are subsequently introduced into the test beakers. When testing “difficult chemicals” (i.e. volatile, unstable, readily biodegradable and adsorbing chemicals) the test can be conducted under flow-through conditions as an alternative to the semi-static design with fixed renewal periods of the medium (see paragraph 29). P. antipodarum survival over the 28 days exposure period and reproduction at the end of the test after 28 days are examined. Reproduction is evaluated by counting the number of embryo in the brood pouch (without distinction of developmental stages) at the end of 28 days exposure. The toxic effect of the test chemical on embryo numbers is expressed as ECX by fitting an appropriate regression model in order to estimate the concentration that would cause x % reduction in embryo numbers or alternatively as the No Observed Effect Concentration and Lowest Observed Effect Concentration (NOEC/LOEC) value (2).

  • 29-July-2016

    English

    Test No. 421: Reproduction/Developmental Toxicity Screening Test

    This screening Test Guideline describes the effects of a test chemical on male and female reproductive performance. It has been updated with endocrine disruptor endpoints, in particular measure of anogenital distance and male nipple retention in pups and thyroid examination.

    The test substance is administered in graduated doses to several groups of males and females. Males should be dosed for a minimum of four weeks. Females should be dosed throughout the study, so approximately 63 days. Matings "one male to one female" should normally be used in this study. This Test Guideline is designed for use with the rat. It is recommended that each group be started with at least 10 animals of each sex. Generally, at least three test groups and a control group should be used. Dose levels may be based on information from acute toxicity tests or on results from repeated dose studies. The test substance is administered orally and daily. The results of this study include clinical observations, body weight and food/water consumption, oestrous cycle monitoring, offspring parameters observation/measurement, thyroid hormone measurement, as well as gross necropsy and histopathology. The findings of this toxicity study should be evaluated in terms of the observed effects, necropsy and microscopic findings. Because of the short period of treatment of the male, the histopathology of the testis and epididymus should be considered along with the fertility data, when assessing male reproductive effects.

  • 29-July-2016

    English

    Test No. 422: Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test

    This screening Test Guideline describes the effects of a test chemical on male and female reproductive performance. It has been updated with endocrine disruptor endpoints, in particular measure of anogenital distance and male nipple retention in pups and thyroid examination.

    The test substance is administered in graduated doses to several groups of males and females. Males should be dosed for a minimum of four weeks. Females should be dosed throughout the study, so approximately 63 days. Matings "one male to one female" should normally be used in this study. This Test Guideline is designed for use with the rat. It is recommended that each group be started with at least 10 animals of each sex. Generally, at least three test groups and a control group should be used. Dose levels may be based on information from acute toxicity tests or on results from repeated dose studies. The test substance is administered orally and daily. The results of this study include clinical observations, body weight and food/water consumption, oestrous cycle monitoring, offspring parameters observation/measurement, thyroid hormone measurement, as well as gross necropsy and histopathology. The findings of this toxicity study should be evaluated in terms of the observed effects, necropsy and microscopic findings. Because of the short period of treatment of the male, the histopathology of the testis and epididymus should be considered along with the fertility data, when assessing male reproductive effects.

  • 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. 489: In Vivo Mammalian Alkaline Comet Assay

    The in vivo alkaline single cell gel electrophoresis assay, also called alkaline Comet Assay is a method measuring DNA strand breaks in eukaryotic cells.

    Each treated group is composed of a minimum of 5 animals of one sex (or of each sex as appropriate). A positive and a vehicle control group are also used. Administration of the treatment consists of daily doses over duration of 2 days or more, ensuring the test chemical reaches the target tissue which can be the liver, the kidney or other tissues if justified.

    Tissues of interest are dissected and single cells/nuclei suspensions are prepared and embedded in agarose on slides. Cells/nuclei are treated with lysis buffer to remove cellular and/or nuclear membranes. The nuclear DNA in the agar is then subjected to electrophoresis at high pH. This results in structures resembling comets which by using suitable fluorescent stain, can be observed by fluorescent microscopy. Based on their size DNA fragments migrate away from the head to the tail, and the intensity of the comet tail relative to the total intensity (head plus tail) reflects the amount of DNA breakage.

  • 29-July-2016

    English

    Financial Management of Flood Risk

    Disasters present a broad range of human, social, financial, economic and environmental impacts, with potentially long-lasting, multi-generational effects. The financial management of these impacts is a key challenge for individuals and governments in developed and developing countries. G20 Finance Ministers and Central Bank Governors and APEC Finance Ministers have recognised the importance and priority of disaster risk management strategies and, in particular, disaster risk assessment and risk financing. The OECD has supported the development of strategies for the financial management of natural and man-made disaster risks, under the guidance of the OECD High-Level Advisory Board on Financial Management of Large-scale Catastrophes and the OECD Insurance and Private Pensions Committee. This work has included the elaboration of an OECD Recommendation on Good Practices for Mitigating and Financing Catastrophic Risks and a draft Recommendation on Disaster Risk Financing Strategies  The Financial Management of Flood Risk extends this work by applying the lessons from the OECD’s analysis of disaster risk financing practices and the development of its guidance to the specific case of floods.

  • 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. 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.

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