By Date


  • 28-July-2015

    English

    Test No. 493: Performance-Based Test Guideline for Human Recombinant Estrogen Receptor (hrER) In Vitro Assays to Detect Chemicals with ER Binding Affinity

    This Performance-Based Test Guideline (PBTG) describes in vitro assays, which provide the methodology for human recombinant in vitro assays to detect substances with estrogen receptor binding affinity (hrER binding assays). It comprises two mechanistically and functionally similar test methods for the identification of estrogen receptor (i.e. ERα) binders and should facilitate the development of new similar or modified test methods. The two reference test methods that provide the basis for this PBTG are: the Freyberger-Wilson (FW) In Vitro Estrogen Receptor (ER) Binding Assay Using a Full Length Human Recombinant ERα, and the Chemical Evaluation and Research Institute (CERI) In Vitro Estrogen Receptor Binding Assay Using a Human Recombinant Ligand Binding Domain Protein. This assay measures the ability of a radiolabeled ligand ([3H]17β-estradiol) to bind with the ER in the presence of increasing concentrations of a test chemical (i.e. competitor).  Test chemicals that possess a high affinity for the ER compete with the radiolabeled ligand at a lower concentration as compared with those chemicals with lower affinity for the receptor. This assay consists of two major components: a saturation binding experiment to characterise receptor-ligand interaction parameters and document ER specificity, followed by a competitive binding experiment that characterises the competition between a test chemical and a radiolabeled ligand for binding to the ER. These test methods are being proposed for screening and prioritisation purposes, but also provide mechanistic information that can be used in a weight of evidence approach.

  • 28-July-2015

    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.

  • 28-July-2015

    English

    Test No. 241: The Larval Amphibian Growth and Development Assay (LAGDA)

    The test guideline of the Larval Amphibian Growth and Development Assay (LAGDA) describes a toxicity test with an amphibian species (African clawed frog (Xenopus laevis)) that considers growth and development from fertilization through the early juvenile period.  It is an assay (typically 16 weeks) that assesses early development, metamorphosis, survival, growth, and partial reproductive maturation. It also enables measurement of a suite of other endpoints that allows for diagnostic evaluation of suspected endocrine disrupting chemicals (EDCs) or other types of developmental and reproductive toxicants. The LAGDA serves as a higher tier test with an amphibian for collecting more comprehensive concentration-response information on adverse effects suitable for use in hazard identification and characterization, and in ecological risk assessment. The general experimental design entails exposing X. laevis embryos at Nieuwkoop and Faber (NF) stage 8-10 (3) to a minimum of four different concentrations of test chemical and control(s) until 10 weeks after the median time to NF stage 62.  There are four replicates in each test concentration with eight replicates for the control. Endpoints evaluated during the course of the exposure (at the interim sub-sample and final sample at completion of the test) include those indicative of generalized toxicity: mortality, abnormal behaviour, and growth determinations (length and weight), as well as endpoints designed to characterize specific endocrine toxicity modes of action targeting oestrogen, androgen or thyroid-mediated physiological processes.

  • 28-July-2015

    English

    Test No. 439: In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method

    This Test Guideline describes an in vitro procedure that may be used for the hazard identification of irritant chemicals (substances and mixtures) in accordance with the UN Globally Harmonized System of Classification and Labelling (GHS) Category 2.  It is based on reconstructed human epidermis (RhE), which in its overall design closely mimics the biochemical and physiological properties of the upper parts of the human skin. Cell viability is measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that is quantitatively measured after extraction from tissues. Irritant test substances are identified by their ability to decrease cell viability below defined threshold levels (below or equal to 50% for UN GHS Category 2). Coloured chemicals can also be tested by used of an HPLC procedure. There are three validated test methods that adhere to this Test Guideline. Depending on the regulatory framework and the classification system in use, this procedure may be used to determine the skin irritancy of test substances as a stand-alone replacement test for in vivo skin irritation testing, or as a partial replacement test, within a tiered testing strategy.

  • 28-July-2015

    English

    Test No. 404: Acute Dermal Irritation/Corrosion

    This method provides information on health hazard likely to arise from exposure to liquid or solid test substance by dermal application. This Test Guideline recommends sequential testing strategies, which include the performance of validated and accepted in vitro or ex vivo tests for corrosion/irritation.

    The albino rabbit is the preferable laboratory animal. The substance to be tested is applied in a single dose to a small area of skin (approximately 6cm²) of an experimental animal; untreated skin areas of the test animal serve as the control. The exposure period is 4 hours. Residual test substance should then be removed. The dose is 0.5ml (liquid) or 0.5g (solid) applied to the test site. The method consists of two tests: the initial test and the confirmatory test (used only if a corrosive effect is not observed in the initial test). All animals should be examined for signs of erythema and oedema during 14 days. The dermal irritation scores should be evaluated in conjunction with the nature and severity of lesions, and their reversibility or lack of reversibility. When responses persist to the end of the 14-day observation period, the test substance should be considered an irritant.

  • 28-July-2015

    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.

  • 28-July-2015

    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.

  • 27-July-2015

    English

    Towards Green Growth? - Tracking Progress

    The 2011 Green Growth Strategy provided initial guidance to governments on how to achieve economic growth and development, while preventing costly environmental damage and inefficient resource use. What progress have countries made in aligning economic and environmental priorities since 2011? This report attempts to evaluate this progress and highlight where there is broad scope to heighten the ambition and effectiveness of green growth policy. It draws lessons from green growth mainstreaming across the OECD’s work programme, notably in terms of how governments can maximise institutional settings to seize economic opportunities surrounding the transition to a green economy, and considers ways to enrich the Green Growth Strategy based on work undertaken since its launch.

  • 27-July-2015

    English

    Webinar: Towards Green Growth? Official Launch of the OECD's Tracking Progress Report

    On July 27, 2015 from 15:00 to 16:30 Paris time, the Green Growth Knowledge Platform (GGKP) hosted a webinar to launch the OECD's new report titled "Towards Green Growth? Tracking Progress". Featuring Carlo Carraro, Catherine L. Mann, Nathalie Girouard and Kevin Urama; this webinar will explore the advances made since the launch of the OECD's green growth strategy in 2011.

    Related Documents
  • 16-July-2015

    English

    Green and Growing, or ripe and rotting? Insights Blog

    In a recent lecture on climate change, the Secretary-General stated that “Tomorrow’s societies engineered around yesterday’s solutions won’t get us there.” The OECD’s work on green growth is just one example of where the organisation is working towards the development of solutions for today.

    Related Documents
  • << < 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 > >>