Dimethylcyclohex-3-ene-1-carbaldehyde

Toxicity to aquatic algae and cyanobacteria

Description of key information

For Vertoliff a 72h algae test was performed with Pseudokirchneriella. Method: This study was carried out using closed systems and according to OECD TG 201. There were 6 treatment groups (5 dose rates of the test item and a control) with three replicates per test concentration and six replicates for the control. At test start 50 mL of the test media were inoculated with nominal 5000 algal cells per mL test medium and defined volumes of the algal suspensions were sampled after 24, 48 and 72 hours for determination of cell densities by spectrophotometric measurement. A supersaturated stock solution of 100 mg/L and its dilutions of 1:3.16, 1:9.99, 1:31.6 and 1:99.7 and a control were tested. The stock solution and its dilutions correspond to the following nominal test concentrations: 100, 31.6, 10.0, 3.16 and 1.0 mg test item/L. Results: Analytical monitoring and the following geometric mean measured concentrations of the test item: 75.0, 23.9, 6.19, 1.40 and 0.350 mg test item/L and a control. At the start of the test 82% of the nominal test concentrations were found (average of all test concentrations). After 24, 48 and 72h 80, 53 and 39% of the nominal value was determined (average of all test concentrations. Cell density control increased 190 fold. The pH value in the control at test start: 8.2, pH value in the control at test end: 9.7; pH values in the test item treatments at test start: 8.2 to 8.4, pH values in the test item treatments at test end: 8.5 to 9.8. The ErC50 and ErC10 are 22.2 and 10.7, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

22.8 mg/L

EC10 or NOEC for freshwater algae:

10.7 mg/L