Protection of a species requires prevention of unacceptable effects on the number, weight, health, and uses of the individuals of that species. A life-cycle toxicity test is conducted to determine what changes in the numbers and weights of individuals of the test species result from effects of the test material on survival, growth, and reproduction. Information might also be obtained on effects of the material on the health and uses of the species.

Results of life-cycle tests with mysids might be used to predict long-term effects likely to occur on mysids in field situations as a result of exposure under comparable conditions.

Results of life-cycle tests with mysids might be used to compare the chronic sensitivities of different species and the chronic toxicities of different materials, and also to study the effects of various environmental factors on results of such tests.

Results of life-cycle tests with mysids might be an important consideration when assessing the hazards of materials to aquatic organisms (see Guide E 1023) or when deriving water quality criteria for aquatic organisms (1).³

Results of a life-cycle test with mysids might be useful for predicting the results of chronic tests on the same test material with the same species in another water or with another species in the same or a different water (2). Most such predictions take into account results of acute toxicity tests, and so the usefulness of the results from a life-cycle test with mysids is greatly increased by also reporting the results of an acute toxicity test (see Guide E 729) conducted under the same conditions.

Results of life-cycle tests with mysids might be useful for studying the biological availability of, and structure-activity relationships between, test materials.

Results of life-cycle tests with mysids might be useful for predicting population effects on the same species in another water or with another species in the same or a different water (3).

1.1 This guide describes procedures for obtaining laboratory data concerning the adverse effects of a test material added to dilution water, but not to food, on certain species of saltwater mysids during continuous exposure from immediately after birth until after the beginning of reproduction using the flow-through technique. These procedures will probably be useful for conducting life-cycle toxicity tests with other species of mysids, although modifications might be necessary.

1.2 Other modifications 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 many other tests. 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 saltwater mysids.

1.3 These procedures are applicable to all 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, and pH and on such materials as aqueous effluents (see also Guide E 1192), leachates, oils, particulate matter, sediments, and surface waters.

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 and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 7.