ASTM E1295-22

5.1?Ceriodaphnia? was first used as a toxicity test organism by Mount and Norberg (2). Introduced for use in effluent and ambient water evaluations, Ceriodaphnia have also been a valuable addition to single chemical test procedures.

5.2?Protection of a population requires prevention of unacceptable effects on the number, weight, health, and uses of the individuals of that species, or species for which the test species serves as a surrogate. A three-brood toxicity test is conducted to help determine changes in survival and the number of neonates produced that result from exposure to the test material.

5.3?Results of three-brood toxicity tests with 5.4?Results of three-brood toxicity tests with 5.5?Results of three-brood toxicity tests with 5.5.1?A 48 or 96-h EC50 or LC50 can sometimes be obtained from a three-brood toxicity test with a known test material, but often all the concentrations in the test will be below the EC50 or LC50. In addition, it is usually desirable to know the EC50 or LC50 before beginning the three-brood test, as a means to determine the concentrations for use in the chronic test (see 10.4.1). It should be noted that results from an acute test may not necessarily correspond to those of a chronic test, due to the addition of food to the chronic test.

5.6?Three-brood toxicity tests with 5.7?Results of three-brood toxicity tests with 5.8?Results of three-brood toxicity tests with 1.1?This guide describes procedures for obtaining data concerning the adverse effects of an effluent or a test material (added to dilution water, but not to food) on Ceriodaphnia dubia Richard 1894, during continuous exposure throughout a portion of the organism's life. These procedures should also be useful for conducting life cycle toxicity tests with other Cladocera (Guide E1193), although modifications will be necessary.

1.2?These procedures are applicable to most chemicals, either individually or in formulations, commercial products, or known mixtures, that can be measured accurately at the necessary concentrations in water. With appropriate modifications these procedures can be used to conduct tests on temperature, dissolved oxygen, pH, dissolved ions, and on such materials as aqueous effluents (see also Guide E1192), leachates, oils, particulate matter, sediments (see also Guide E1706), and surface waters. Renewal tests might not be applicable to materials that have high oxygen demand, are highly volatile, are rapidly biologically or chemically transformed, or sorb to test chambers. If the concentration of dissolved oxygen falls below 4 mg/L or the concentration of test material decreases by more than 20 % in test solution(s) at any concentration between renewals, more frequent renewals might be necessary.

1.3?Other modifications of these procedures might be justified by special needs or circumstances. Results of tests conducted using unusual procedures are not likely to be comparable to results of many other tests. Comparisons of results obtained using modified and unmodified versions of these procedures might provide useful information on new concepts and procedures for conducting three-brood toxicity tests with C. dubia.

1.4?This guide is arranged as follows:

1.5?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. 1.6?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.