Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 25 April to 13 July 2012
Reliability:
1 (reliable without restriction)
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Analytical monitoring:
yes
Details on sampling:
Samples for analysis were taken at 0 and 24 hours (freshly prepared media), and 24 and 48 hours (old test media).
Details on test solutions:
Due to the complex and insoluble nature of the test substance (UVCB), a Water Accommodated Fraction (WAF) approach was considered to be the most suitable method of test media preparation.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: daphnid
- Source: continuously bred in the laboratory
- Age at study initiation (mean and range, SD): less than 24-hour old
- Method of breeding: breeding conditions same as test conditions
- Feeding during test: no

ACCLIMATION
- Acclimation conditions (same as test or not): breeding conditions same as test conditions
- Type and amount of food: Chlorella vulgaris daily and and seaweed during holding
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Test temperature:
19.2 - 21.9 °C (test media)
pH:
7.66 - 8.37
Dissolved oxygen:
at least 8.15 mg/L
Nominal and measured concentrations:
Nominal loading rates of 0, 1.0, 2.2, 4.6, 10, 22, 46 and 100 mg CAE/L in ASTM medium.
Details on test conditions:
TEST SYSTEM
- Test vessel: glass dishes containing 150 mL of test medium
- No. of organisms per vessel: 5 daphnids
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Photoperiod: light cycle of 16 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobilization was observed by visual control after 24 and 48 hours of exposure.
Duration:
48 h
Dose descriptor:
NOELR
Effect conc.:
1 mg/L
Nominal / measured:
nominal
Conc. based on:
other: WAF
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOELR
Effect conc.:
0.68 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
3.7 mg/L
Nominal / measured:
nominal
Conc. based on:
other: WAF
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
2.5 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
mobility
Reported statistics and error estimates:
The EL50 and EC50 values were calculated using the Spearman-Kärber method.

The percentage of immobilization after 24 hours and 48 hours of exposure are presented in the table below

Table 1     Immobilization of daphnids exposed for 48 hours to WAFs of CAE

Nominal loading rate (mg/L)

Nb of daphnids

Immobilization at

24 hours

48 hours

Nb.

%

Nb.

%

0

4*5

0

0

0

0

1.0

4*5

0

0

0

0

2.2

4*5

0

0

4

20

4.6

4*5

0

0

12

60

10

4*5

7

35

20

100

22

4*5

11

55

20

100

46

4*5

11

55

20

100

100

4*5

20

100

20

100

Validity criteria fulfilled:
yes
Conclusions:
In the conditions of the test, the nominal loading rate of CAE at which no significant (≤ 10%) dose related immobility of Daphnia magna occurred was 1.0 mg/L. The NOELR was therefore considered to be 1.0 mg/L (0.68 mg/L based on estimated CAE concentrations).
Based on nominal loading rates, the 48-hour EL50 value of CAE to Daphnia magna was determined to be 3.7 mg/L (2.5 mg/L based on estimated CAE concentrations).
Executive summary:

In a semi-static acute toxicity test performed according to OECD guideline No.202, daphnids (Daphnia magna) were exposed for 48 hours to nominal loading rates ranging between 1.0 and 100 mg CAE/L in ASTM medium. A control group was also included.Four replicate test and control vessels were prepared (5 daphnids/test vessel). Due to the complex and insoluble nature of the test substance (UVCB), a Water Accommodated Fraction (WAF) approach was considered to be the most suitable method of test media preparation.

Samples of test media were analysed for Total Organic Carbon (TOC), as a measure of the dissolved test substance concentration in new and old test media. Given that TOC analysis is not compound specific, the results represent only an estimation of test substance concentration. Therefore the endpoints were based on both nominal loading rates and estimated CAE concentrations.

After 48 hours of exposure, no immobilization was observed in the control and in the nominal loading rate of 1.0 mg/L. The percentages of immobilisation were 20% and 60% at the nominal loading rates of 2.2 mg/L and 4.6 mg/L, respectively. The percentage of immobilisation was 100% from 10 mg/L to 100 mg/L.

 

Nominal loading rate (mg/L)

Estimated CAE concentration (mg/L)

Exposure

EL50

NOELR

EC50

NOEC

24 h

22.4

4.6

19.2

3.2

48 h

3.7

1.0

2.5

0.68

Description of key information

Based on nominal loading rates, the 48-hour EL50 value of CAE to Daphnia magna was determined to be 3.7 mg/L (2.5 mg/L based on estimated CAE concentrations).

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
3.7 mg/L

Additional information