Significance and Use
5.1 Protection of an aquatic species requires prevention of unacceptable effects on populations in natural habitats. Toxicity tests are conducted to provide data that may be used to predict what changes in numbers and weights of individuals might result from similar exposure to the test material in the natural aquatic environment. Information might also be obtained on the effects of the material on the health of the species.
5.2 Results of life-cycle tests with D. magna are used to predict chronic effects likely to occur on daphnids in field situations as a result of exposure under comparable conditions.
5.2.1 Life-cycle tests with D. magna are used to compare the chronic sensitivities of different species, the chronic toxicities of different materials, and study the effects of various environmental factors on the results of such tests.
5.2.2 Life-cycle tests with D. magna are used to assess the risk of materials to aquatic organisms (see Guide E1023) or derive water quality criteria for aquatic organisms (1).3
5.2.3 Life-cycle tests with D. magna are used to extrapolate the results of chronic toxicity tests on the same test material with the same species in another water or with another species in the same or a different water. Most such predictions take into account the results of acute toxicity tests, and so the usefulness of the results of a life-cycle test with D. magna may be increased by reporting the results of an acute toxicity test (see Guide E729) conducted under the same conditions. In addition to conducting an acute toxicity test with unfed D. magna, it may be relevant to conduct an acute test in which the daphnids are fed the same as in the life-cycle test to see if the presence of that concentration of that food affects the results of the acute test and the acute-chronic ratio (ACR) (see 10.3.1).
5.2.4 Life-cycle tests are used to evaluate the biological availability of, and structure-activity relationships between, test materials and test organisms.
5.3 Results of life-cycle tests with D. magna might be influenced by temperature (2), quality of food, composition of dilution water, condition of test organisms, test media (for example, water hardness), and other factors.
Scope
1.1 This guide covers procedures for obtaining laboratory data concerning the adverse effects of a test material (added to dilution water, but not to food) on Daphnia magna Straus, 1820, during continuous exposure throughout a life-cycle using the renewal or flow-through techniques. These procedures also should be useful for conducting life-cycle toxicity tests with other invertebrate species and cladocerans from the same genus (for example, Daphnia pulex), although modifications might be necessary.
1.2 These procedures are applicable to most chemicals, either individually or in formulations, commercial products, or known mixtures. With appropriate modifications, these procedures can be used to conduct tests on temperature, dissolved oxygen, pH, and on such materials as aqueous effluents (also see Guide E1192), leachates, oils, particulate matter, sediments, and surface waters. The technique, (renewal or flow-through), will be selected based on the chemical characteristics of the test material such as high oxygen demand, volatility, susceptibility to transformation (biologically or chemically), or sorption to glass.
1.3 Modification of these procedures might be justified by special needs or circumstances. Although using appropriate procedures is more important than following prescribed procedures, results of tests conducted using unusual procedures are not likely to be comparable to results of standard test procedures. Comparison of results obtained using modified and unmodified versions of these procedures might provide useful information on new concepts and procedures for conducting life-cycle toxicity tests with D. magna. Appendix X3 provides modifications for conducting the chronic toxicity test method with D. pulex Leydig, 1860.
1.4 This guide is arranged as follows:
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| Referenced Documents | 2 |
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| Terminology | 3 |
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| Summary of Guide | 4 |
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| Significance and Use | 5 |
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| Apparatus | 6 |
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|  Facilities | 6.1 |
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|  Construction Materials | 6.2 |
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|  Test Chambers | 6.3 |
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|  Cleaning | 6.4 |
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|  Acceptability | 6.5 |
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| Reagents | 7 |
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|  Purity of Reagents | 7.1 |
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| Hazards | 8 |
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| Dilution Water | 9 |
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|  Requirements | 9.1 |
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|  Source | 9.2 |
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|  Treatment | 9.3 |
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|  Characterization | 9.4 |
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| Test Material | 10 |
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|  General | 10.1 |
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|  Stock Solutions | 10.2 |
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|  Test Concentrations(s) | 10.3 |
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| Test Organisms | 11 |
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|  Species | 11.1 |
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|  Age | 11.2 |
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|  Source | 11.3 |
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|  Brood Stock | 11.4 |
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|  Food | 11.5 |
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|  Handling | 11.6 |
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|  Harvesting Young | 11.7 |
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|  Quality | 11.8 |
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| Procedure | 12 |
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|  Experimental Design | 12.1 |
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|  Dissolved Oxygen | 12.2 |
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|  Temperature | 12.3 |
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|  Loading | 12.4 |
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|  Selection of Test System | 12.5 |
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|  Beginning the Test | 12.6 |
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|  Care and Maintenance | 12.7 |
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|  Feeding | 12.8 |
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|  Duration | 12.9 |
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|  Biological Data | 12.10 |
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|  Other Measurements | 12.11 |
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| Analytical Methodology | 13 |
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| Acceptability of Test | 14 |
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| Calculation of Results | 15 |
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| Report | 16 |
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| Keywords | 17 |
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| Appendixes |
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|  Appendix X1 Statistical Guidance |
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|  Appendix X2 Food |
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|  Appendix X3 Modifications for Conducting Chronic Life Cycle Analysis Tests with Daphnia Pulex |
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1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 8.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
