6-(cyclohexylamino)-3-methyl-3H-dibenz[f,ij]isoquinoline-2,7-dione

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020-06 till 2020-11-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Sampling schedule:
Control : on day 0, 7 and 17 in the freshly prepared media;
on day 3, 10 and 19 in the old media

Test concentrations : all test concentrations on day 0, 7 and 17 in the freshly prepared
media; on day 3, 10 and 19 in the old media

Vehicle:

no

Details on test solutions:

Calibration solutions
For the calibration, 21.1 mg of the test item was dissolved in acetonitrile/tetrahydrofuran 8/2 and then made up with the same solvent to the mark in a 100 mL volumetric flask (211.0 mg/L). This stock solution was diluted further with acetonitrile to prepare an intermediate solution (1055.0 µg/L). This intermediate solution was diluted further to prepare calibration solutions between 0.0528 µg/L and 52.75 µg/L test item. The calibration solutions were analysed.

Standard Solutions used for Verification of the Calibration and Blank Test
For the verification during the study, 22.43 mg of the test item was dissolved in acetonitrile/tetrahydrofuran 8/2 and then made up with the same solvent to the mark in a 100 mL volumetric flask (224.3 mg/L). This stock solution was diluted further with acetonitrile to prepare one verification solution (4.206 µg/L).

Test organisms (species):

Daphnia magna

Details on test organisms:

Young female Daphnia, aged less than 24 hours at the start of the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

14.2 °dH to 15.6 °dH
(= 253 - 278 mg/L CaCO3)

Test temperature:

18 - 22 °C

pH:

The pH was within the range 6 - 9.

Nominal and measured concentrations:

The following nominal concentrations of the test item were tested in the acute test: 1, 10 and 100 mg/L (preciding range finder for the reproduction test). In the reproduction test the following nominal concetrations of the test item were tested: 0.0063, 0.013, 0.025, 0.050 and 0.1 mg/L.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.005 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

Nominal concentration Analytical values
(time-weighted
mean)
[mg/L] [mg/L]

21d-NOEC (reproduction) (tα 0.05) : 0.025 0.0050

21d-LOEC (reproduction) (tα 0.05) : 0.050 0.0086

21d-NOEC (mortality) (tα 0.05) : ≥ 0.100 ≥ 0.019

21d-LOEC (mortality) (tα 0.05) : > 0.100 > 0.019

Validity criteria fulfilled:

yes

Conclusions:

After A 21 day period, a NOEC of 0.005 mg/l (measured concentration) was obtained on the basis of reproduction.

Executive summary:

After a 21d-exposure period, the total number of living offspring produced per parent animal which did not die accidentally or inadvertently during the test was assessed. In addition, the reproduction was calculated based on the production of living offspring by the surviving parent organism. The reproductive output of the Daphnia exposed to the test item was compared to that of the control in order to determine the Lowest Observed Effect Concentration (LOEC) and the No Observed Effect Concentration (NOEC) according to Williams Multiple Sequential t-Test procedure. Additionally, the survival of the parent Daphnia and the time to production of first brood was determined.

 

Results [mg/L]

	Nominal concentration [mg/L]	Analytical values (time-weighted mean) [mg/L]
21d-NOEC (reproduction) (tα 0.05)	0.025	0.0050
21d-LOEC (reproduction) (tα 0.05)	0.050	0.0086
21d-NOEC (mortality) (tα 0.05)	≥ 0.100	≥ 0.019
21d-LOEC (mortality) (tα 0.05)	> 0.100	> 0.019

 

Description of key information

After A 21 day period, a NOEC of 0.005 mg/l (measured concentration) was obtained on the basis of reproduction.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

0.005 mg/L