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)

Short-term toxicity to aquatic invertebrates

Description of key information

In a semi-static immobilization GLP test (BASF SE, 2018) Daphnia magna (< 24 h old) were exposed to the test item for 48 hours according to the OECD 202. The 48h-EC50 was determined to be 0.997 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.997 mg/L

Additional information

In a static immobilization GLP test (BASF SE, 2018) Daphnia magna (< 24 h old) were exposed to the test item for 48 hours according to the OECD 202. The Daphnia were exposed to a nominally range of concentrations of 0 (Control), 0 (control), 0.46, 1, 2.2, 4.6 and 10 mg/L. The test substance is a poorly water soluble mixture; therefore a water accommodated fraction (WAF) was prepared following general guidance provided in OECD 23. Each test solution was prepared separately (differential loading) by directly adding test substance to test medium and stirring for about 2 days. Undissolved test substance was removed by centrifugation (approximately 20 min at about 17700 G). The aqueous fraction was inspected visually for the presence of any undissolved test substance by observing the scattering of a laser light through the test solution (Tyndall effect). The Tyndall effect in the centrifuged test solutions was positive and the aqueous fraction was additionally filtered through a membrane filter (Whatman OE66, pore width 0.2 μm). The first 50-100 mL of filtered solution was discarded (used to condition the filter). The Tyndall effect was negative in the filtered solutions. The exposure was started after separation of the undissolved material. After filtration, the solutions were stirred for approx. 10 minutes to achieve adequate dissolved oxygen levels. The control solution will be treated in the same way. Fresh test solutions were prepared and renewed daily to maximize the exposure to all soluble components of the test substance. 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). An untreated control (M4 Medium without addition of the test item) and a positive control with sodium chloride were performed. The EC50(48h) of the reference substance sodium chloride was determined to be 4.18 g/L. This result is within the range of 3.88 – 7.22 g/L and indicates that the culture of Daphnia magna used in this study is responding normally to toxic stress. The 48h-EC50/EL50 was determined to be 0.997 mg/L (result based on loading rate).