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This Test Guideline, covering nanomaterials spanning from 1 nm to 1000 nm, is intended for particle size and particle size distribution measurements of nanomaterials. The TG includes the following methods: Atomic Force Microscopy (AFM), Centrifugal Liquid Sedimentation (CLS)/Analytical Ultracentrifugation (AUC), Dynamic Light Scattering (DLS), Differential Mobility Analysis System (DMAS), (Nano)Particle Tracking Analysis (PTA/NTA), Small Angle X-Ray Scattering (SAXS), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). For measuring the diameter and length of fibres, analysing images captured with electron microscopy is currently the only method available.

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.

Skin phototoxicity (photoirritation) is defined as an acute toxic response elicited by topically or systemically administered photoreactive chemicals after the exposure of the skin to environmental light. The in vitro reconstructed human epidermis phototoxicity test (RhE PT) is used to identify the phototoxic potential of a test chemical after topical application in reconstructed human epidermis (RhE) tissues in the presence and absence of simulated sunlight. Phototoxicity potential is evaluated by the relative reduction in viability of cells exposed to the test chemical in the presence as compared to the absence of simulated sunlight. Chemicals identified as positive in this test may be phototoxic in vivo following topical application to the skin, eyes, and other external light-exposed epithelia.

This method provides information on health hazard likely to arise from exposure to test substance (liquids, solids and aerosols) by application on the eye. This Test Guideline is intended preferably for use with albino rabbit. The test substance is applied in a single dose in the conjunctival sac of one eye of each animal. The other eye, which remains untreated, serves as a control. The initial test uses an animal; the dose level depends on the test substance nature. A confirmatory test should be made if a corrosive effect is not observed in the initial test, the irritant or negative response should be confirmed using up to two additional animals. It is recommended that it be conducted in a sequential manner in one animal at a time, rather than exposing the two additional animals simultaneously. The duration of the observation period should be sufficient to evaluate fully the magnitude and reversibility of the effects observed. The eyes should be examined at 1, 24, 48, and 72 hours after test substance application. The ocular irritation scores should be evaluated in conjunction with the nature and severity of lesions, and their reversibility or lack of reversibility. Use of topical anesthetics and systemic analgesics to avoid or minimize pain and distress in ocular safety testing procedures is described.

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 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 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.

The in vitro micronucleus test is a genotoxicity test for the detection of micronuclei in the cytoplasm of interphase cells. Micronuclei may originate from acentric chromosome fragments (i.e. lacking a centromere), or whole chromosomes that are unable to migrate to the poles during the anaphase stage of cell division. The assay detects the activity of clastogenic and aneugenic test substances in cells that have undergone cell division during or after exposure to the test substance. This Test Guideline allows the use of protocols with and without the actin polymerisation inhibitor cytochalasin B. Cytochalasin B allows for the identification and selective analysis of micronucleus frequency in cells that have completed one mitosis, because such cells are binucleate. This Test Guideline also allows the use of protocols without cytokinesis block provided there is evidence that the cell population analysed has undergone mitosis.   

This Test Guideline describes in vitro assays, which use Androgen Receptor TransActivation (ARTA) to detect Androgen Receptor Agonists and Antagonists. The ARTA assay methods are mechanistically and functionally similar test methods that provide information on the transcription and translation of a reporter gene following the binding of a chemical to the androgen receptor and subsequent transactivation. The cell lines used in these assays express AR and have been stably transfected with an AR-responsive luciferase reporter gene, and are used to identify chemicals that activate (i.e. act as agonist) or inhibit (i.e. act as antagonists) AR-dependent transcription. Some chemicals may, in a cell type-dependent manner, display both agonist and antagonist activity and are known as selective AR modulators. The AR is activated following ligand binding, after which the receptor-ligand complex binds to specific DNA responsive elements and transactivates the receptor gene, resulting in an increase cellular expression of the luciferase enzyme. The enzyme then transforms the substrate to a bioluminescent product that can be quantitatively measured with a luminometer. This Test Guideline includes ARTA assays using the AR-EcoScreenTM cell line, the AR-CALUX® cell line, and 22Rv1/MMTV_GR-KO cell line.

As a European Green Capital 2023, Tallinn has a unique momentum to set the foundations for its transition from a linear to a circular economy. The newly created Circular Economy Department in the city administration is a signal of this transformation. The city conceives the circular economy as a means to advance environmental goals while generating opportunities for job creation and stimulating innovation through a systems approach. This report summarises the findings from a 20-month policy dialogue between the OECD, the city of Tallinn and stakeholders from public, private and non-profit sectors. It provides the main components of existing circular economy initiatives promoted in Estonia and in the city of Tallinn, key challenges and policy recommendations to help the city develop its long-term vision on the circular economy, setting targets for the future.

Québec is mobilised to become an innovation and entrepreneurial leader in North America, giving higher education institutions (HEIs) a central role in this drive. HEIs are pivotal in developing skills and nurturing talent, connecting and contributing to their communities, including firms, public authorities and civil society. The Stratégie québécoise de recherche et d’investissement en innovation (SQRI) has placed HEIs at the fore front of the provincial innovation and entrepreneurship efforts, including with an explicit spatial approach, through the “innovation zones”. This review assesses the “geography of higher education” in Québec through the examination of ten case study HEIs. These case studies represent examples of innovative and entrepreneurial HEIs that support entrepreneurship and innovation in their communities. In particular, the case studies tell the story of the province of Québec in creating sustainable entrepreneurship and innovation, connecting actors and mobilising resources and policies. The review offers actionable policy recommendations to generate further progress in this direction.

This report provides a global assessment and outlook on wildfire risk in the context of climate change. It discusses the drivers behind the growing incidence of extreme wildfires and the attribution effect of climate change. It outlines the environmental, social and economic impacts of wildfires by illustrating the losses and costs observed during recent extreme wildfire events. Building on this, the report presents the findings of a cross-country comparative analysis of how countries’ policies and practices have evolved in recent years in light of observed and projected changes in wildfire risk. The analysis draws on in-depth case studies conducted in Australia, Costa Rica, Greece, Portugal and the United States. The report underlines the urgent need for governments to scale up climate change adaptation efforts to limit future wildfire costs.

The growing demand for raw materials in the Hungarian economy projected up to 2050 is expected to exert significant additional pressure on the environment, putting the country at risk of missing important environmental goals and opportunities to strengthen the competitiveness and resilience of its economy. Despite the notable progress in decoupling environmental pressures from economic activities over the past 20 years, several challenges remain. The transition to a circular economy has significant potential to address these challenges. To fully realise the circular potential of its economy, Hungary will need to adopt a comprehensive circular economy policy framework. This report outlines a set of key elements for the development of the Hungarian national circular economy strategy and action plan. It identifies priority areas that are deemed critical to the Hungarian circular economy transition, including: biomass and food, construction and plastics, as well as cross-cutting horizontal tools to facilitate an economy-wide circular transition. It also provides 45 policy recommendations and suggests specific implementation actions across the priority areas for the short, medium and long term.

Global education systems face an array of huge challenges, including question marks over how to remain relevant in a fast-changing world. This report Teaching for the Future: Global Engagement, Sustainability and Digital Skills outlines the challenges and key trends for teaching and schools, and sets out ambitious proposals to improve education standards to ensure learning caters to the needs of all students regardless of background. The report was used as the basis to launch discussions about the state of global education at the International Summit on the Teaching Profession held in Washington D.C., April 2023. The summit brought together education ministers, union leaders and other representatives from the teaching profession from high-performing and improving education systems to review the quality of teaching and learning across the world. Topics discussed included the future of learning and ways to radically reimagine how education systems function in the decades to come; analysis of how to attract and support the development of high-quality teachers and teaching practices in the age of digitalisation; and ways to support the teaching of global competencies in schools, and how to promote equitable and inclusive learning environments for all.

This annual publication provides details of taxes paid on wages in OECD countries. This year’s edition focuses on the impact of recent inflation on labour taxation in the OECD and how countries adjust their tax systems in response. For the year 2022, the report also examines personal income taxes and social security contributions paid by employees, social security contributions and payroll taxes paid by employers, and cash benefits received by workers. It illustrates how these taxes and benefits are calculated in each member country and examines how they impact household incomes. The results also enable quantitative cross-country comparisons of labour cost levels and the overall tax and benefit position of single persons and families on different levels of earnings. The publication shows average and marginal effective tax rates on labour costs for eight different household types, which vary by income level and household composition (single persons, single parents, one or two earner couples with or without children). The average tax rates measure the part of gross wage earnings or labour costs taken in tax and social security contributions, both before and after cash benefits, and the marginal tax rates the part of a small increase of gross earnings or labour costs that is paid in these levies.