Reports

This Test Guideline describes an in vitro screen for chemical effects on steroidogenesis, specifically the production of 17ß-estradiol (E2) and testosterone (T). The human H295R adreno-carcinoma cell line, used for the assay, expresses genes that encode for all the key enzymes for steroidogenesis. After an acclimation period of 24 h in multi-well plates, cells are exposed for 48 h to seven concentrations of the test chemical in at least triplicate. Solvent and a known inhibitor and inducer of hormone production are run at a fixed concentration as negative and positive controls. At the end of the exposure period, cell viability in each well is analyzed. Concentrations of hormones in the medium can be measured using a variety of methods including commercially available hormone measurement kits and/or instrumental techniques such as liquid chromatography-mass spectrometry. Data are expressed as fold change relative to the solvent control and the Lowest-Observed-Effect-Concentration. If the assay is negative, the highest concentration tested is reported as the No-Observed-Effect-Concentration.

This Test Guideline describes an in vitro assay that may be used for identifying water soluble ocular corrosives and severe irritants as defined by the UN Globally Harmonized System of Classification and Labelling, Category 1. The assay is performed in a well where a confluent monolayer of Madin-Darby Canine Kidney (MDCK) is used as a separation between two chambers. It uses a fluorescein dye as marqueur. The test substance has the potential to impair the junctions of the MDCK cells and thus to increase the monolayer¡¯s permeability. Consequently the fluorescein passes through the monolayer and the fluorescein leakage (FL) increases. The FL is calculated as a percentage of leakage relative to both a blank control and a maximum leakage control. The concentration of test substance that causes 20% FL (FL20, in mg/mL) is calculated and used in the prediction model for identification of ocular corrosive and severe irritants. The cut-off value of FL20 to identify water soluble chemicals as ocular corrosives/severe irritants is ¡Ü 100mg/mL. The FL test method should be part of a tiered testing strategy.

This Test Guideline (TG) describes the IL-2 Luc Assay test method to evaluate the potential immunotoxic effects of chemicals on T lymphoblastic cell line. This cell line allows quantitative measurement of luciferase gene induction by detecting luminescence from well-established light producing luciferase substrates as indicators of the activity of IL-2, IFN-γ and GAPDH in cells following exposure to immunotoxic chemicals. The method is intended to be used as a part of a battery to determine immunotoxic potential of chemicals.

This Test Guideline (TG) describes a method to determine the hydrophobicity index (Hy) of nanomaterials (NMs), through an affinity measurement. Hydrophobicity is defined as 'the association of non-polar groups or molecules in an aqueous environment which arises from the tendency of water to exclude non-polar molecules'. By measuring their binding rate to different engineered surfaces (collectors), Hy expresses the tendency of the NMs to favour the binding to a non-polar (hydrophobic) surface because of its low affinity for water. The method applies to NMs dispersed in an aqueous solution or to NM powders after their dispersions in aqueous solutions, with or without a surfactant, using a recommended protocol.

The present Key Event based Test Guideline (TG) addresses the human health hazard endpoint skin sensitisation, following exposure to a test chemical. More specifically, it addresses the activation of dendritic cells, which is one Key Event on the Adverse Outcome Pathway (AOP) for Skin Sensitisation. Skin sensitisation refers to an allergic response following skin contact with the tested chemical, as defined by the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS). This TG provides three in vitro test methods addressing the same Key Event on the AOP: (i) the human cell Line Activation Test or h-CLAT method, (ii) the U937 Cell Line Activation Test or U-SENS and (iii) the Interleukin-8 Reporter Gene Assay or IL-8 Luc assay. All of them are used for supporting the discrimination between skin sensitisers and non-sensitisers in accordance with the UN GHS. Test methods described in this TG either quantify the change in the expression of cell surface marker(s) associated with the process of activation of monocytes and DC following exposure to sensitisers (e.g. CD54, CD86) or the changes in IL-8 expression, a cytokine associated with the activation of DC. In the h-CLAT and U-SENS assays, the changes of surface marker expression are measured by flow cytometry following cell staining with fluorochrome-tagged antibodies. In the IL-8 Luc assay, the changes in IL-8 expression are measured indirectly via the activity of a luciferase gene under the control of the IL-8 promoter. The relative fluorescence or luminescence intensity of the treated cells compared to solvent/vehicle control are calculated and used in the prediction model, to support the discrimination between sensitisers and non-sensitisers.

This Test Guideline describes a cytotoxicity-based in vitro assay that is performed on a confluent monolayer of Statens Seruminstitut Rabbit Cornea (SIRC) cells, cultured on a 96-well polycarbonate microplate. After five-minute exposure to a test chemical, the cytotoxicity is quantitatively measured as the relative viability of SIRC cells using the MTT assay. Decreased cell viability is used to predict potential adverse effects leading to ocular damage. Cell viability is assessed by the quantitative measurement, after extraction from the cells, of blue formazan salt produced by the living cells by enzymatic conversion of the vital dye MTT, also known as Thiazolyl Blue Tetrazolium Bromide. The obtained cell viability is compared to the solvent control (relative viability) and used to estimate the potential eye hazard of the test chemical. A test chemical is classified as UN GHS Category 1 when both the 5% and 0.05% concentrations result in a cell viability smaller than or equal to (≤) 70%. Conversely, a chemical is predicted as UN GHS No Category when both 5% and 0.05% concentrations result in a cell viability higher than (>) 70%.

This Test Guideline describes the Medaka Extended One Generation Test (MEOGRT), which exposes fish over multiple generations to give data relevant to ecological hazard and risk assessment of chemicals, including suspected endocrine disrupting chemicals (EDCs).  Exposure in the MEOGRT starts with spawning fish (P or F0 generation) and continues until hatching (until two weeks post fertilization, wpf) in the second (F2) generation. This Test Guideline measures several biological endpoints.  Primary emphasis is given to potential adverse effects on population relevant parameters including survival, gross development, growth and reproduction (fecundity).  Secondarily, in order to provide mechanistic information and provide linkage between results from other kinds of field and laboratory studies, where there is a posteriori evidence for a chemical having potential endocrine disrupter activity (e.g. androgenic or oestrogenic activity in other tests and assays) then other useful information is obtained by measuring vitellogenin (vtg) mRNA (or vitellogenin protein, VTG), phenotypic secondary sex characteristics (SSC) as related to genetic sex, and evaluating histopathology.

IUCLID (International Uniform Chemical Information Database) is a software application designed to record, store, maintain and exchange data on chemicals. It is a key software application for both regulatory bodies and the chemical industry where it is used in the implementation of various regulatory programmes. IUCLID can be customised and configured to manage chemical data in different contexts and is a platform employing globally harmonised data elements pertinent to chemicals. It is continuously updated to provide greater customisation, extension and integration with other tools. This third edition provides the latest updates on IUCLID features and processes, including the use of PostgreSQL, an updated matrix view of the use of IUCLID in OECD countries, the new release schedule, and information on new tools to support the use of IUCLID (Data Uploader) and the IUCLID Customisation Forum.

Chemical accidents with serious consequences continue to happen in OECD Member countries and worldwide. Over the past decades, successive major accidents have caused deaths, injuries, significant environmental pollution and massive economic losses – from the hydrogen fluoride leak in Gumi (Korea) in 2012, the ammonium nitrate explosion in West, Texas (United States) in 2013 or, recently, the blow-up of a chemical facility in Tarragona (Spain) and the explosion at the port of Beirut (Lebanon) in 2020, and the blast in Leverkusen (Germany) in 2021. This third edition of the OECD Guiding Principles for Chemical Accident Prevention, Preparedness and Response provides guidance for the safe planning and operation of hazardous installations. It aims to support public authorities and industry in taking appropriate actions to prevent chemical accidents and to mitigate impacts of accidents that do nevertheless occur. These guiding principles apply to fixed installations at which hazardous substances are produced, processed, handled, stored, used or disposed of, in such a form and quantity that there might be a risk of occurrence of a chemical accident. These guiding principles constitute the technical guidance supporting the implementation of the Decision-Recommendation of the Council concerning Chemical Accident Prevention, Preparedness and Response adopted in 2023.

Compromised kidney function is associated with an array of environmental contaminants and chemicals, including heavy metals, certain organic solvents, and polycyclic aromatic hydrocarbons (PAHs), as well as food and waterborne pathogens. Many of these hazards are subject to regulation, or may be considered for regulation, in order to reduce exposures and prevent human health risks. However, valuation estimates for kidney effects that can be used in cost-benefit analyses are few, particularly willingness-to-pay estimates. In particular, there appears to be no willingness-to-pay (WTP) estimate available for reduced risk of chronic kidney disease and therefore no estimate for the Value of a Statistical Case (VSC) of chronic kidney disease. This paper is part of the series of large scale willingness to pay (WTP) studies resulting from the Surveys to elicit Willingness to pay to Avoid Chemicals related negative Health Effects (SWACHE) project that intends to improve the basis for doing cost benefit analyses of chemicals management options and environmental policies in general. The paper details a stated preference survey estimating WTP to reduce the risk of symptomatic chronic kidney disease, termed serious kidney disease in the survey instrument, filling an important gap in the valuation literature and addressing a need for applied benefits analysis for chemicals regulation. The SWACHE serious kidney impairment survey was fielded in 10 countries: Canada, Chile, China, Denmark, Germany, Italy, Norway, Türkiye, the United Kingdom and the United States.