Aquatic ecotoxicity
Aquatic Invertebrates
OECD 202 Daphnia sp. Acute Immobilisation Test
Study Purpose and Introduction:
The corrosivity potential of a chemical may be predicted by measurement of its cytotoxic effect, as reflected in the MTT assay, on the reconstituted human epidermis. The reconstructed human epidermis closely mimics the biochemical and physiological properties of the upper parts of the human skin and its use for skin corrosivity testing involves the topical application of test materials to the surface of the skin, and the subsequent assessment of their effects on cell viability. This method is approved by international regulatory agencies as a replacement for the identification of corrosives in the in vivo Rabbit skin assay (OECD 404) and is specifically approved as a replacement for the in vivo skin corrosivity test within OECD 431.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 4, No. 431, “In Vitro Skin Corrosion: Reconstructed Human Epidermis (RhE) Test Method”
OECD 202 Daphnia sp. Acute Immobilisation Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the influence of the test item on the mobility, respectively survival of Daphnia magna. Young daphnids, aged less than 24 hours at the start of the test, is exposed to aqueous test media containing the test item at a range of concentration for 48. Immobilisation (and any sub-lethal effects) are observed and recorded at 24 and 48 hours and compared with the control. As endpoints of the test, the 48-h EC× and NOEC/LOEC values are determined from the obtained data.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 202, “Daphnia sp. Acute Immobilisation Test” (link: https://www.oecd-ilibrary.org/environment/test-no-202-daphnia-sp-acute-immobilisation-test_9789264069947-en)
OECD 211 Daphnia magna Reproduction Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the ecotoxicological effects of the test item on the reproductive output of Daphnia magna in a semi-static test system in which the test medium is periodically renewed during the experiment. Young female Daphnia (the parent animals) aged less than 24 hours at the start of the test were exposed to aqueous test media containing the test item at a range of concentration for 21 days. The total number of living offspring produced per parent animal alive at the end of the test was assessed. Other parameters, such as survival of parent animals, growth (i.e. size of parents), time to production of first brood, number of broods per parent animal, number of aborted broods, and presence of male neonates or ephippia were also assessed.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 211, “Daphnia magna Reproduction Test” (link: https://www.oecd-ilibrary.org/environment/test-no-211-daphnia-magna-reproduction-test_9789264185203-en)
OECD 218 Sediment-Water Chironomid Toxicity Using Spiked Sediment
Study Purpose and Introduction:
The purpose of this study is to determine the effect of the test item to Chironomus riparius larvae. For this purpose, first instar Chironomus larvae are exposed in a static test to sediment-water system containing the test item initially applied to the sediment at different test item concentrations under defined conditions. The recorded effects are the symptoms of intoxication of the larvae, the total number of the fully emerged male and female midges and the number of egg ropes laid until the last day of the study.
Source: https://www.scielo.br/j/aabc/
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 218, “Sediment-Water Chironomid Toxicity Using Spiked Sediment” (link: https://www.oecd-ilibrary.org/environment/test-no-218-sediment-water-chironomid-toxicity-using-spiked-sediment_9789264070264-en)
OECD 219 Sediment-Water Chironomid Toxicity Using Spiked Water
Study Purpose and Introduction:
The purpose of this study is to determine the effect of the test item to Chironomus riparius larvae. For this purpose, first instar Chironomus larvae are exposed in a static test to sediment-water system containing the test item initially applied to the water at a limit test item concentration / at different test item concentrations under defined conditions. The recorded effects are the symptoms of intoxication of the larvae, the total number of the fully emerged male and female midges and the number of egg ropes laid until the last day of the study.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 219, “Sediment-Water Chironomid Toxicity Using Spiked Water” (link: https://www.oecd-ilibrary.org/environment/test-no-219-sediment-water-chironomid-toxicity-using-spiked-water_9789264070288-en)
OECD 225 Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment
Study Purpose and Introduction:
This method is designed to assess the effects of prolonged exposure to sediment-associated chemicals on the reproduction and the biomass of the endobenthic oligochaete Lumbriculus variegatus (Müller). The method is described for static test conditions. Worms of similar physiological state are exposed to a series of toxicant concentrations applied to the sediment phase of a sediment-water system (artificial sediment amended with a food source and reconstituted water). Test vessels without the test substance serve as controls. The test animals are exposed to the sediment-water systems for a period of 28 days. The endpoints of this type of study are the ECx for reproduction and biomass. In addition the No Observed Effect Concentration (NOEC), and the Lowest Observed Effect Concentration (LOEC) may be calculated.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 225, “Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment” (link: https://www.oecd-ilibrary.org/environment/test-no-225-sediment-water-lumbriculus-toxicity-test-using-spiked-sediment_9789264067356-en)
OECD 235 Chironomus sp., Acute Immobilisation Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the influence of the test item on the mobility of Chironomus riparius larvae. First instar Chironomus riparius larvae are exposed to a range of concentrations of the test item in water-only system for a period of 48 hours. Immobilisation is recorded at 24 and 48 hours. The EC50 is calculated at 24 and 48 hours (if data allow).
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 235, “Chironomus sp., Acute Immobilisation Test” (link: https://www.oecd-ilibrary.org/environment/test-no-235-chironomus-sp-acute-immobilisation-test_9789264122383-en)
Fish
OECD 203: Fish, Acute Toxicity Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the acute toxicity (mortality or sub-lethal effects) of the test item on Zebrafish (Danio rerio). For this purpose, young fish are exposed to aqueous test media containing the test item at a range of concentrations for 96 hours. As endpoints of the test, LC50 and NOEC/LOEC values are determined from the obtained data for 24, 48, 72 and 96 hours of exposure. The test is run according to international test guidelines using the recommended fish species Zebrafish (Danio rerio).
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 203, “Fish, Acute Toxicity Test” (link: https://www.oecd-ilibrary.org/environment/test-no-203-fish-acute-toxicity-test_9789264069961-en)
OECD 203: Fish, Acute Toxicity Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the acute toxicity (mortality or sub-lethal effects) of the test item on Zebrafish (Danio rerio). For this purpose, young fish are exposed to aqueous test media containing the test item at a range of concentrations for 96 hours. As endpoints of the test, LC50 and NOEC/LOEC values are determined from the obtained data for 24, 48, 72 and 96 hours of exposure. The test is run according to international test guidelines using the recommended fish species Zebrafish (Danio rerio).
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 203, “Fish, Acute Toxicity Test” (link: https://www.oecd-ilibrary.org/environment/test-no-203-fish-acute-toxicity-test_9789264069961-en)
OECD 210: Fish, Early-life Stage Toxicity Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the chronic toxicity of the test item to early life stages (embryo, larvae and juveniles) of fish.
Tests with early-life stages of fish (FELS) are intended to define the lethal, and to a limited extent, sub-lethal effects of chemicals on the stages and species tested. For this purpose, early-life stages (embryo, larval and juvenile) of zebrafish (Danio rerio) is exposed to a range of concentrations of the test substance under semi-static conditions. The test begin by placing fertilized eggs in the test chambers and continue until 30 days post-hatch of the control fish. Lethal and sub-lethal effects are assessed (as much as possible) and compared with control values to determine the lowest observed effect concentration (LOEC) in order to determine the no observed effect concentration (NOEC) and/or the ECx for each response assessed.
The method of application is recommended by the OECD guideline No. 210 and zebrafish (Danio rerio) is one of the fish species also recommended by the international test guidelines for testing toxicity on fish.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 210, “Fish, Early-life Stage Toxicity Test” (link: https://www.oecd-ilibrary.org/environment/test-no-210-fish-early-life-stage-toxicity-test_9789264203785-en)
Aquatic plants
OECD 203: Fish, Acute Toxicity Test
Study Purpose and Introduction:
The purpose of this study is to evaluate the acute toxicity (mortality or sub-lethal effects) of the test item on Zebrafish (Danio rerio). For this purpose, young fish are exposed to aqueous test media containing the test item at a range of concentrations for 96 hours. As endpoints of the test, LC50 and NOEC/LOEC values are determined from the obtained data for 24, 48, 72 and 96 hours of exposure. The test is run according to international test guidelines using the recommended fish species Zebrafish (Danio rerio).
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 203, “Fish, Acute Toxicity Test” (link: https://www.oecd-ilibrary.org/environment/test-no-203-fish-acute-toxicity-test_9789264069961-en)
OECD 201: Freshwater Alga and Cyanobacteria, Growth Inhibition Test
Study Purpose and Introduction:
The purpose of this study is to determine the effect of the test item on the growth of a unicellular green algal species Raphidocelis subcapitata (previously known as Pseudokirchneriella subcapitata).
Exponentially growing cultures of Raphidocelis subcapitata are exposed to various concentrations of the test item under defined conditions. Nominal concentrations are determined based on the results of preliminary experiment. The algal growth in relation to a control culture is determined over a fixed test period of 72 hours and thus, over several algal generations. The test method of application and the test species Raphidocelis subcapitata are recommended by the test guidelines.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 201, “Freshwater Alga and Cyanobacteria, Growth Inhibition Test” (link: https://www.oecd-ilibrary.org/
OECD 221: Lemna sp. Growth Inhibition Test
Study Purpose and Introduction:
The purpose of the study is to assess the phytotoxicity of the test item on the freshwater aquatic plant Lemna gibba. Exponentially growing cultures of Lemna gibba are exposed to various concentrations of the test item over a period of 7 days.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 221, “Lemna sp. Growth Inhibition Test” (link: https://www.oecd-ilibrary.org/
OECD 239: Water-Sediment Myriophyllum Spicatum Toxicity Test
Study Purpose and Introduction:
This test is designed to assess the toxicity of chemicals on the growth of the rooted aquatic plants (Myriophyllum spicatum) growing in water-sediment system.
Shoot apices of healthy and non-flowering plant are potted in standardised, artificial sediment supplemented with additional nutrient and exposed to at least five concentrations of the chemical over a period of 14 days. The measured quantitative variables include growth of shoot length and development of fresh and dry weight, and the measured qualitative variables include presence or not of chlorosis and necrosis or growth deformities.
Guidelines and literature:
OECD Guidelines for the Testing of Chemicals, Section 2, No. 239, “Water-Sediment Myriophyllum Spicatum Toxicity Test” (link: https://www.oecd-ilibrary.org/
Water-sediment Glyceria maxima toxicity test
Study Purpose and Introduction:
This test method has determined the effects of a test item on the vegetative growth or increase in biomass of Glyceria maxima.
Guidelines and literature:
EFSA Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters. EFSA Journal 2013; 11 (7): 3290.; Ring-test protocol for evaluating the effects of Imazapyr on Glyceria maxima in a water-sediment system, July 2018