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  • 25-June-2024

    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.

  • 25-June-2024

    English

    Test No. 442D: In Vitro Skin Sensitisation - Assays addressing the Adverse Outcome Pathway Key Event on Keratinocyte activation

    The present Key Event based Test Guideline addresses the human health hazard endpoint skin sensitisation, following exposure to a test chemical. Skin sensitisation refers to an allergic response following skin contact with a tested chemical, as defined by the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS). This Test Guideline is proposed to address a Key Event leading to skin sensitisation, namely keratinocyte activation. This Key Event on the Adverse Outcome Pathway (AOP) leading to skin sensitisation takes place in the keratinocytes and includes inflammatory responses as well as gene expression associated with specific cell signalling pathways such as the antioxidant/electrophile response element (ARE)-dependent pathways. This Test Guideline provides three in vitro test methods addressing the same Key Event on the AOP for skin sensitisation: (i) the ARE-Nrf2 luciferase KeratinoSens™ test method, (ii) the ARE-Nrf2 luciferase LuSens test method and (iii) the Epidermal Sensitisation Assay – EpiSensA. The KeratinoSens and the Lusens are in vitro ARE-Nrf2 luciferase-based test methods and the EpiSensA is based on gene expression quantification using Reverse Transcription- quantitative PCR in reconstructed human epidermis models. The proposed test methods are used for supporting the discrimination between skin sensitisers and non-sensitisers in accordance with the UN GHS. Performance standards have been developed to enable the validation of similar test methods.

  • 25-June-2024

    English

    Test No. 442B: Skin Sensitization - Local Lymph Node Assay: BrdU-ELISA or –FCM

    The Local Lymph Node Assay: BrdU-ELISA (LLNA:BrdU-ELISA) is a non-radioactive modification to the LLNA method for identifying potential skin sensitizing test substances and measuring the proliferation of lymphocytes they induce in the auricular lymph nodes. The method described in mouse  is based on the use of measuring 5-bromo-2-deoxyuridine (BrdU) content, an analogue of thymidine, as an indicator of this proliferation. A minimum of four animals is used per dose group, with a minimum of three concentrations of the test substance, plus a concurrent negative control group and a positive control group. The experimental schedule is during 6 days. Thereafter, the animals are killed and a single cell suspension of lymph node cells (LNC) is prepared. The procedure for preparing the LNC is crucial, in particular for the small lymph nodes in NC animals. Then the BrdU content in DNA of lymphocytes is measured by ELISA using a commercial kit of by Flow Cytometry (FCM). This study includes: measurements (weighing, BrdU) and clinical daily observations. The results are expressed as the Stimulation Index (SI) obtained by calculation from the mean BrdU labelling index. The SI should be ≥1.6 for the ELISA method or ≥2.7 for the FCM method for identifying the test material as a potential skin sensitizer.  

  • 18-June-2024

    English

    Series on Risk Management - Publications by number

    The series on Risk Management covers methodologies for both governments and industry to manage risks posed by chemicals and, when appropriate, to harmonise risk management activities. The OECD provides information on the following areas: perfluorinated chemicals, substitution of hazardous chemicals, sustainable chemistry and others.

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  • 26-February-2024

    English

    Best Available Techniques (BAT) to Prevent and Control Industrial Pollution

    On 8 November 2023, the OECD organised a webinar to explore the current understanding of the Best Available Techniques (BAT) approaches and their future. It addressed key challenges, opportunities for the identification of promising emerging techniques for effective pollution prevention and reduction and the importance of cross-collaboration between regulatory authorities, industries, research institutes and technology providers.

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  • 31-January-2024

    English

    Chemical Safety and Biosafety Progress Report

    The Chemical Safety and Biosafety Progress Report is released every eight months. Its purpose is to provide an update on the projects, events and activities. Information on new publications as well as dates and venues of upcoming events and meetings are given.

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  • 22-January-2024

    English

    Unique Identifier for Transgenic Plants

    The OECD developed the BioTrack Product Database which accommodates Unique Identifiers to each transgenic (or genetically engineered) plant that is approved for commercial use, including planting and food/feed use. These Unique Identifiers are intended to be used as "keys" to access information of each transgenic product in this database and to ensure the safety of modern biotechnology products

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  • 21-December-2023

    English

    Biocides publications (Chronological order)

    The Covid-19 pandemic has challenged regulators, health professionals, industry and the public in responding quickly, decisively and efficiently to the impact and consequences of this virus. This report looks at the lessons learned during the Covid-19 crisis to investigate approaches for possible future emergency situations.

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  • 12-December-2023

    English

    Adverse Outcome Pathways

    The OECD released three new Adverse Outcome Pathways following scientific review and OECD endorsement.

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  • 13-October-2023

    English

    Series on Testing and Assessment: publications by number

    The OECD has been developing guidance documents and tools for the use of alternative methods such as (Q)SAR, chemical categories and Adverse Outcome Pathways (AOPs) as a part of Integrated Approaches for Testing and Assessment (IATA). The objective is to increase experience with the use of IATA by developing case studies, which constitute examples of predictions that are fit for regulatory use.

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