Cobaltate(1-), bis[2-(3-chlorophenyl)-2,4-dihydro-4-[[2-hydroxy-5-(methylsulfonyl)phenyl]azo]-5-methyl-3H-pyrazol-3-onato(2-)]-, hydrogen, compd. with [1R-(1α,4aβ,10aα)]-1,2,3,4,4a,9,10,10a-octahydro-1,4a-dimethyl-7-(1-methylethyl)-1-phenanthrenemethanamine (1:1)

Toxicity to aquatic plants other than algae

Description of key information

The toxicity of the test substance to Lemna gibba was determined in a study (BASF SE, 2018) according to the principles of OECD 221 (2006). After 7 days, the ErL50 based on frond number was determined to be 14.6 mg/L, the ErC10 based on frond number was determined to be 0.69 mg/L and the NOErLR was determined to be < 0.320 mg/L

Key value for chemical safety assessment

EC50 for freshwater plants:

14.6 mg/L

EC10 or NOEC for freshwater plants:

0.69 mg/L

Additional information

The toxicity of the test substance to Lemna gibba was determined in a study (BASF SE, 2018) according to the principles of OECD 221 (2006). The growth of Lemna gibba exposed to the test item was investigated in a 7 day semi-static test with renewals on day 0 and day 2. The test substance is poorly water soluble and a complex mixture. Therefore, the test solutions were prepared separately for each test concentration following general guidance provided in OECD 23. Each test solution was prepared by directly adding the required mass of test substance to test medium and stirring for approximately 2 days. After centrifugation, the test solutions were colored and the Tyndall effect was positive. Then filtration with a membrane filter (pore width 0.2 μm) was done. The first 50-100 mL of filtered solution was discarded (used to condition the filter). After filtration all test solutions were visibly colorless and clear. The Tyndall effect in the test solutions was negative. The TOC values of all the test solutions were measured at the start and end of one renewal interval as an additional water quality parameter. The definitive test was performed using following nominal concentrations 0 (control), 0.32, 1.0, 3.2, 10, 32 and 100 mg/L as loading rate. Concentration control analysis was not performed because a sufficiently sensitive method for analyses in the required concentration range was not available. However, all reasonable efforts were taken to produce a saturated solution of all soluble components of the test substance in test media. Since the test substance is a mixture, the test solution is considered a water saturated fraction (WSF) after removal of all undissolved test substance. The term “loading rate” is advocated to express exposure to a WSF and is considered analogous to the nominal concentration. According to OECD 23, for tests with chemicals that can not be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on loading rate (for mixtures). A blank control with the test solution (20X AAP) without test material and a reference control with the reference substance 3,5-dichlorophenol were performed. After 7 days the ErC50 of the reference substance 3,5-dichlorophenol was determined to be 10.3 mg/L. The validity criteria were fulfilled.  After 7 days, the ErL50 based on frond number was determined to be 14.6 mg/L, the ErL10 based on frond number was determined to be 0.69 mg/L and the NOErLR was determined to be < 0.320 mg/L