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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
48 hours
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted according to OECD guideline 202 (2004)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Batch number - LPBS2A2005Appearance- white powder
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):Not applicable

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples of the test media for determination of the actual test substance concentrations were taken immediately before introduction of the Daphnia, before and after the change of the test media at 24 hours and after 48 hours. Actual concentrations of the test substance in the test media were determined in the surplus of the test media at the beginning of the test and at 24 hours (new media). The pooled test media of the replicates were used for test substance determination at 24 hours (old media) and at the end of the test. One sample each was taken and then analysed in duplicate by HPLC. The samples were analysed at the day of sampling.

Test solutions

Vehicle:
no
Details on test solutions:
Stock solutions were prepared at the start of the test and 24 hours thereafter by dilution of 26.0 mg (0 h) and 25.9 mg (24 h) test substance in 250 mL reconstituted water according to ISO 6341 by stirring for 5 minutes.As recommended by the guideline, the pHs of the stock solutions were adjusted to that of the dilution water before addition of the test substance. The 0 hours stock solution had an initial pH value of 4.65 and was adjusted with 0.1M NaOH to 8.11 and with 0.1M HCl to a final pH of 7.51. The 24 hours stock solution had an initial pH of 4.61 and was adjusted with 0.1M NaOH to a final pH of 7.34. These pH adjusted stock solutions were used for mediapreparation.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Neonates of Daphnia magna (Crustacea, Cladocera), less than 24 hours old, were obtained by hatching ephippia, supplied in the microbiotest "Daphtoxkit F TM " (Daphnia magna; Fa. Micro BioTests Inc; Kleimoer 15, B-9030 Mariakerke (Gent); BELGIUM).The ephippia were hatched in the laboratory in a petri dish containing reconstituted water in a temperature controlled room at approx. 20-22 °C under continuous illumination of approximately 6 000 Lux. According to MicroBioTests Inc. the largest hatching occurs between 72 and 80 hours and the daphnia must be collected at the latest 90 hours after initiation of hatching. The neonates were collected for this investigation at approximately 88.5 hours after initiation of hatching in the first experiment and 85 hours after hatching in the second experiment. Approximately 2 hours before the start of the test the neonates were fed with a suspension of Spirulina powder (MicroBioTests Inc.), as also in traditional Daphnia cultures the neonates have the opportunity to take up some feed particles.Batch No. of the ephippia used: DM161209.

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Post exposure observation period:
Not applicable

Test conditions

Hardness:
230 mg CaCO3/L
Test temperature:
20-21°C
pH:
Between 7.5 and 7.8 in the relevant test substance media and between 7.7 and 8.0 in the control media.
Dissolved oxygen:
8.2 - 9.6 mg O2/L
Salinity:
Not applicable
Nominal and measured concentrations:
Nominal concs - control, 6.25, 12.5, 25, 50 and 100 mg/L - measured concs - 5.28, 10.53, 23.47, 49.87 and 102.07 mg/L
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
23 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Results with reference substance (positive control):
To check the reliability of the test conditions for acute toxicity studies to Daphnia magna at Seibersdorf Labor GmbH a static reference test with K2Cr2O7 is conducted at least yearly. The last reference test was conducted in December 2009 and gave a 24 h EC50 of 1.1 mg K2Cr2O7 per litre (95% confidence interval of 0.86 to 1.5 mg/L) which is within the acceptability range of 0.6 - 2.1 mg/L given by the OECD guideline 202.
Reported statistics and error estimates:
The EC50-values and their confidence limits were calculated with the moving average method of W. Thompson, modified by C.S. Weil, Drug and Chemical Toxicology, 6 (6), 595-603 (1983)

Any other information on results incl. tables

Mean measured concentrations

Nominal concentration (mg/L)

Measured concentration (mg/L)

Mean (mg/L)

0 hours (new)

24 hours (old)

24 hours (new)

48 hours (old)

Control

<QL

<QL

<QL

<QL

-

6.25

5.93

4.46

6.28

4.67

5.28

12.5

12.45

9.10

12.49

8.68

10.53

25

24.44

23.69

25.51

20.55

23.47

50

49.08

50.36

49.24

50.84

49.87

100

102.86

102.41

100.67

102.36

102.07

QL: Quantification Limit of the analytical method used (3.55 mg/L)

 

 

Immobilised Daphnia

Nominal concentration (mg/L)

Immobility

24 hours

48 hours

number

%

number

%

Control

0

0

0

0

6.25

2

10

2

10

12.5

0

0

0

5

25

0

0

0

0

50

1

5

3

15

100

2

10

4

20

20 Daphnia were exposed in each treatment

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Based on the geometric mean concentrations the 48-hour EC50was determined to be >102 mg/L. The corresponding no-observed effect concentration (NOEC) was determined to be 23 mg/L
Executive summary:

This template will be updated with the results to the pH adjusted study when available.

The 48 hour acute toxicity of succinic acid to Daphnia magna was determined in a semi-static test according to the OECD 202 guideline.

Daphnia were exposed over a 48 hour period to succinic acid at nominal concentrations of 0 (control), 6.25, 12.5, 25, 50 and 100 mg/L. As recommended by the guideline, the pHs of the stock solutions used to prepare the test media were adjusted to that of the dilution water before addition of the test substance.  Concentrations of succinic acid were verified analytically at test initiation, after 24 hours in both new and old test media and test termination.  Geometric mean measured concentrations was 5.28, 10.53, 23.47, 49.87 and 102.07 mg/L. Based on the geometric mean concentrations the 48-hour EC50was determined to be >102 mg/L. The corresponding no-observed effect concentration (NOEC) was determined to be 23 mg/L.