1.1 This test guide is designed to give general guidance for assessing the potential phytotoxicity of water soluble test material to freshwater emergent macrophytes.

1.2 This renewal test continuously exposes selected plant species, growing in sediment, to various concentrations of test material, dissolved in a nutrient solution.

1.3 This test guide is based on the Toxic Substances Control Act (TSCA) guidelines for conducting toxicity tests with terrestrial plants and is applicable to most water soluble chemicals , either individually or in formulations, commercial products, or known mixtures (see Guides E 1193 and E 1598). With slight modifications the procedure also might be used for effluents (see Guide E 1192).

1.4 Results from this toxicity test can be used to report an EC50 or NOEC (see Section 3) based on the concentration of chlorophyll extracted from the plants (see Guides D 3731 and E 1218). In some situations, it might be necessary to only test at one concentration to determine whether or not that specific concentration is toxic to the plants.