At the end of the 301 F modified OECD screening test, all the liquors underwent a toxicity test on D. magna. This is recommended by EC 648/2004 as an additional test for assessing the toxicity of biodegradation test liquors. Organism immobilization did not occur in any cases, after 24- and 48-h contact, suggesting the absence of toxic by-products (at least at significant concentrations), due to the biodegradation process.