[4-[[4-(diethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]diethylammonium acetate

Short-term toxicity to aquatic invertebrates

Description of key information

In an acute immobilization test with Daphnia magna Straus a 48-h EC50 of 0.028 mg/L (based on nominal concentrations) was determined for the test item (BASF 50E0469/14X513, 2016).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.028 mg/L

Additional information

Key study (BASF 50E0469/14X513, 2016):
Immobilization of Daphnia magna exposed to the test item was investigated during a 48-hour semi-static test with daily renewals according to OECD guideline 202 (2004). The water fleas were exposed to a control and the following nominal test item concentrations: 0.0039, 0.0086, 0.019, 0.041, 0.091, 0.20, 0.45, 1.0 and 2.2 mg/L. The Daphnia magna were observed for immobilization after 24 and 48 hours of exposure. The test item was not stable under the test conditions within 24 hours. Therfore, the endpoint values were calculated based on nominal concentrations.

In the control and in the test item concentration of 0.0039 mg/L no immobilization was observed during exposure. At exposure termination in the test item concentrations of 0.0086, 0.019, 0.041 and 0.091 mg/L immobilization was 10, 45, 60 and 85 %, respectively. In the test item concentrations 0.20, 0.45, 1.0 and 2.2 mg/L the immobilization was 100 %. The endpoint values were based on the nominal test item concentrations after 48 h and are given below:

The EC50/ 48 h value is 0.028 mg/L (95% confidence interval 0.021 – 0.038)
The LOEC/ 48 h value is 0.019 mg/L
The NOEC/ 48 h value is 0.0086 mg/L

Supporting read across study (BASF 1/90/0937/50/1, 1990):

The acute immobilization test with Daphnia magna (STRAUS) was assessed in an immobilization test. In this test young Daphnia magna STRAUS (< 24 h old) were exposed to the read across test substance (CAS 83968-15-4) for 48 hours according to Directive 79/831/EEC Annex V, Part C (1989) under non-GLP conditions. The nominal concentrations were 0.0009, 0.0019, 0.0039, 0.0078, 0.0156, 0.0312, 0.0625, 0.125, 0.250, 0.5, 1 mg/L and a control (0 mg test item/L). No concentrations were measured. The study encompassed 4 replicates per concentration and 4 replicate per control. The number of the organisms per vessel was 5. The mobility of the Daphnia was determined by visual observation after 3, 6, 24 and 48 hours. No reference substance as positive control was tested. The 48h-EC0 was determined to be 0.0625 mg/L and the 48h-EC50 was determined to be 0.12 mg/L. All reported results refer to the nominal concentrations.