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This Test Guideline is designed to assess the effects of prolonged exposure of chemicals to the sediment-dwelling larvae of the freshwater dipteran Chironomus sp. First instar chironomid larvae are exposed to at least five concentrations of the test chemical in sediment - water systems. The test substance is spiked into the sediment and first instar larvae are subsequently introduced into test beakers in which the sediment and water concentrations have been stabilised. Chironomid emergence and development rate is measured at the end of the test. The maximum exposure duration is 28 days for C. riparius, C. yoshimatsui, and 65 days for C. tentans. The limit test corresponds to one dose level of 1000 mg/kg. Larval survival and weight may also be measured after 10 days if required (using additional replicates as appropriate). The study report should include the development time and the total number of fully emerged midges (sex and number are recorded daily), the observation of any abnormal behaviour the number of visible pupae that have failed to emerge and any egg masses deposition. The data are analysed either by using a regression model in order to estimate the concentration that would cause x % reduction in emergence or larval survival or growth, or by using statistical hypothesis testing to determine a NOEC/LOEC.
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L’Essai de stimulation locale des ganglions lymphatiques: BrdU-ELISA (ELGL: BrdU-ELISA) est une variante non radioactive de la méthode ELGL qui vise à identifier les substances chimiques sensibilisantes et à mesurer la prolifération lymphocytaire qu’ils induisent dans les ganglions lymphatiques auriculaires. Cette méthode décrite chez la souris se base sur la quantification de la 5-bromo-2- désoxyuridine (BrdU), un analogue of thymidine, dans l’ADN des lymphocytes, comme indicateur de cette prolifération. Quatre animaux au minimum sont employés par groupe de dose, avec au minimum trois concentrations de la substance d'essai, plus un groupe contrôle négatif traité avec le véhicule seul, et un contrôle positif, au besoin. Le protocole expérimental dure 6 jours. Ensuite, les animaux sont euthanasiés et une suspension unicellulaire de cellules de ganglions lymphatiques (CGL) est préparée. La procédure de dispersion des CGL est une étape cruciale, en particulier pour les ganglions lymphocytaires très petits chez le animaux du groupe contrôle négatif. Ensuite la BrdU dans l’ADN des lymphocytes est quantifiée à l’aide d’un kit de dosage ELISA ou par cytométrie de flux (FCM). L’essai inclut des mesures (pesée, BrdU) et des observations cliniques quotidiennes. Les résultats sont exprimés par l’Indice de Stimulation (IS) obtenu par calcul à partir des indices moyens de marquage BrdU pour les différents groupes. Un SI ≥1.6 pour la méthode ELISA ou un SI ≥2.7 pour la cytométrie de flux justifie l’évaluation de la substance d’essai comme sensibilisant potentiel.
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Les lignes directrices de l’OCDE pour les essais de produits chimiques est une collection d’environ 100 des plus pertinents tests reconnus à l’échelle internationale et méthodes d’essai utilisées par les gouvernements, l’industrie et des laboratoires indépendants afin d’identifier et de définir les dangers potentiels des nouvelles substances chimiques, préparations chimiques et mélanges chimiques. Cette batterie d’outils est particulièrement utile pour les professionnels dans les tests réglementaires de sécurité et les produits chimiques et produits chimiques de notification et d’enregistrement des produits chimiques. Ils peuvent également être utilisés pour la sélection et le classement des produits chimiques au cours du développement de nouveaux produits chimiques et de produits et de recherche en toxicologie. Ce groupe d’essais est consacré aux effets sur la santé.
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This document is a report of the Workshop on a framework for the development and use of integrated approaches to testing and assessment which was held on 17-19 November 2014 in Crystal City VA, USA. This framework should provide guiding principles, and technical guidance on how results from alternative approaches (in silico, in chemico, in vitro including high throughput and high content test methods) should be interpreted for characterising (both qualitatively and quantitatively) the adverse effects in animals and humans and/ or the environment, so that they can be used for hazard identification, hazard characterisation and risk assessment. The workshop was organised in close cooperation with the World Health Organisation following a proposal from OECD member countries in June 2013.
Chemical tests and reagents --- Chemical reagents --- Reagents, Chemical --- Indicators and test-papers --- Chemical tests and reagents.
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La méthode d'essai EASZY (Endocrine Active Substances using Zebrafish embrYos) est une méthode de dépistage in vivo de type mécanistique, conçue pour détecter les perturbateurs endocriniens agissant comme agonistes des récepteurs des œstrogènes (estrogen receptors, ER), en induisant l'expression de la protéine fluorescente verte (Green Fluorescent Protein, GFP) sous le contrôle du promoteur du gène cyp19a1b. L'essai EASZY permet de détecter l'activité œstrogénique de produits chimiques sur des embryons de poisson-zèbre transgénique tg(cyp19a1b:GFP) exposés pendant 96 heures aux stades du développement embryonnaire. À la fin de l'expérience, la fluorescence de chaque éleuthéroembryon nouvellement éclos est mesurée au microscope à fluorescence. Le crâne du poisson-zèbre étant transparent aux premiers stades de son développement, la GFP est observée, imagée et quantifiée in vivo. L'intensité de fluorescence est quantifiée au moyen d'un logiciel d'analyse d'image.
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This document provides the second edition of Guidance Document 23 on Aqueous-Phase Aquatic Toxicity Testing of Difficult Test Chemicals. Whilst this guidance is targeted towards tests described by the OECD Test Guidelines identified it may also be relevant to other tests. The guidance relates to the practical aspects of carrying out valid tests with "difficult" test chemicals and mixtures and presenting the results. The guidance is considered to reflect good practice but it is important to recognise that some test chemicals and mixtures will present specific scientific and technical issues that may fall outside its scope. This document is divided into five substantive sections covering guidance for carrying out a preliminary assessment of test chemical stability; general considerations on selection of exposure systems; stock and test solution preparation and exposure systems; sampling of test solution for analysis; and calculating and reporting test results.
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The Test Guideline (TG) describes the use of liver S9 sub-cellular fraction (RT-S9) of rainbow trout (Oncorhynchus mykiss) as a metabolising system to determine the clearance (CL, IN VITRO, INT ) of a test chemical using a substrate depletion approach. Introduction of the test chemical to the RT-S9 incubation medium initiates the reaction. In order to collect samples at various time points, the reaction is terminated by transferring an aliquot of the medium to a stopping solution. The decrease of the test chemical concentration from the incubation vial is measured with a validated analytical method and used to determine the CL, IN VITRO, INT. The value obtained can then be used to improve in silico predictions of the test chemical bioaccumulation in fish.
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The residues in Livestock studies are conducted in order to quantify levels of residues in meat, milk, eggs and edible meat by-products following the use of a pesticide product. The situations to which such studies apply include application of a pesticide to raw agricultural commodities (RACs), and the feeding by livestock; pesticides that may be directly applied to livestock; and pesticides that are used in livestock premises. The primary purposes of the Residues in Livestock study are to provide: the basis for establishing maximum residue limits (MRLs) and for conducting dietary intake assessments for consumer safety. Separate feeding studies should be conducted for a ruminant (lactating dairy cows) and poultry (egg-laying hens). The test substance(s) should be applied daily (during at least 28 days) preferably by capsule. A Residues in Livestock study will normally comprise 3 different dose levels, 1X, 3X and 10X. Three animals per dose group (and one for the control) should be used for ruminants. For hens 9-10 animals per dose group (and 3 to 4 animal for control per study) should be used. The study report should include: daily feed consumption, bodyweights measurement, milk or egg production and analyse (after and before dosing), detailed observations (health problems…) and tissues analyse.
Chemical tests and reagents --- Biological reagents --- Chemical reagents --- Reagents, Chemical --- Indicators and test-papers --- Reagents, Biological --- Biological assay --- Indicators (Biology)
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The OECD Guidelines for the Testing of Chemicals is a collection of about 150 of the most relevant internationally agreed testing methods used by government, industry and independent laboratories to identify and characterise potential hazards of chemicals. They are a set of tools for professionals, used primarily in regulatory safety testing and subsequent chemical and chemical product notification, chemical registration and in chemical evaluation. They can also be used for the selection and ranking of candidate chemicals during the development of new chemicals and products and in toxicology research. This group of tests covers health effects.
Environment --- Chemical tests and reagents --- Chemical reagents --- Reagents, Chemical --- Indicators and test-papers --- Chemical tests and reagents. --- Chemistry. --- Toxins.
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This method provides information on health hazard likely to arise from short-term exposure to a test chemical by dermal route. Test chemicals should not be administered at doses that are known to cause marked pain and distress due to potential corrosive or severely irritant actions. Groups of animals, of a single sex, are exposed via the dermal route to the test chemical in a stepwise procedure using the appropriate fixed doses. The initial dose level is selected at the concentration expected to produce clear signs of toxicity without causing severe toxic effects or mortality. Further groups of animals may be tested at higher or lower fixed doses, depending on the presence or absence of signs of toxicity or mortality. This procedure continues until the dose causing toxicity or no more than one death is identified, or when no effects are seen at the highest dose or when deaths occur at the lowest dose. Subsequently, observations of effects and deaths are made. Animals which die during the test are necropsied, and at the conclusion of the test the surviving animals are sacrificed and necropsied. The method provides information on the hazardous properties and allows the substance to be classified for acute toxicity according to the Globally Harmonised System of classification and labelling of chemicals.
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