1.1 This practice covers procedures for obtaining data concerning toxicity of a test material to a multi-trophic level freshwater community.

1.2 These procedures also might be useful for studying the fate of test materials and transformation products, although modifications and additional analytical procedures might be necessary.

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 many other tests. Comparison of results obtained using modified and unmodified versions of these procedures might provide useful information concerning new concepts and procedures for conducting multi-trophic level tests.

1.4 This practice is arranged as follows:

Section Referenced Documents 2 Terminology 3 Summary of Practice 4 Significance and Use 5 Apparatus 6 Facilities 6.1 Container 6.2 Equipment 6.3 Hazards 7 Microcosm Components 8 Medium 8.1 Medium Preparation 8.2 Sediment 8.3 Microcosm Assembly 8.4 Test Material 9 General 9.1 Stock Solution 9.2 Nutrient Control 9.3 Test Concentration(s) 9.4 Test Organisms 10 Algae 10.1 Animals 10.2 Specificity of Organisms 10.3 Sources 10.4 Algal Culture Maintenance 10.5 Animal Culture Maintenance 10.6 Procedure 11 Experimental Design 11.1 Inoculation 11.2 Culling 11.3 Addition of Test Material 11.4 Measurements 11.5 Reinoculations 11.6 Analytical Methodology 12 Data Processing 13 Calculations of Variables from Measurements 14 Statistical Analyses 15 Acceptability of Test 16 Interpretation of Results 17 Report 18 Annex A1 Appendices Relationship of Media X1 Data Sheets X2 Statistical Guidance X3

1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

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