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 June 6 to July 7, 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
This study was performed according to OECD Guideline 202 and EU Method C.2 with GLP statement. All validity criteria were fulfilled.
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes (incl. certificate)
Remarks:
UK GLP Compliance Programme (inspected on April 12, 2005/ signed on June 01, 2005)
Analytical monitoring:
yes
Details on sampling:
- Concentrations: The aqueous samples were diluted with methanol and/or water to bring the expected analyte concentration within the calibration range of 0 – 5.0 mg/L.
- Sampling method: Samples of 100 mL of media were taken from the control and test vessels at 0 and 48 hours for analysis.
- Sample storage conditions before analysis: Sample were analyzed immediately after sampling and stored in a refrigerator in case further analysis was required.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The test substance (200 mg) was added directly to a volumetric flask containing Elendt M4 medium (1500 mL). The contents of the flask were shaken vigorously and treated by ultrasound for 30 minutes, with periods of intermittent vigorous shaking, before being made up to volume (2 L) and stirred overnight in darkness. On cessation of stirring, aliquots (42.7, 93.9, 207 or 455 mL) of the medium were further diluted with Elendt M4 medium to provide the test medium at 4.27 to 45.5 mg/L; the remainder was used to provide the test medium at 100 mg/L.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna (Straus)
- Source: Institute National de Recherche Chimique Appliqué (IRChA), France
- Age at study initiation: less than 24 hours
- Method of breeding: Culture conditions ensure that the stock animals reproduce by parthenogenesis.
- Feeding during test: No feed was given during the exposure period

ACCLIMATION
- Acclimation conditions: Stock cultures of Daphnia magna were maintained in glass vessels containing approximately 0.8 litres of Elendt M4 culture medium in a temperature-controlled laboratory at nominally 20 ± 2 °C. A photoperiod of 16 hours light : 8 hours dark was maintained, with periods of subdued lighting at the beginning and end of each light phase. The culture medium was renewed at least twice each week.
- Feeding: Cultures were fed daily with a suspension of the unicellular green alga, Chlorella vulgaris, to provide nominally 0.1 to 0.2 mg carbon per daphnid, per day, except during the initial three days when a slightly lower ration was given.
- Health during acclimation (any mortality observed): No data

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Post exposure observation period:
None
Hardness:
250 mg/L as CaCO3
Test temperature:
19.6-21.5 °C
pH:
7.76-8.00
Dissolved oxygen:
within the range 98 to 107% air saturation value (ASV)
Salinity:
ELENDT M4 MEDIUM

Trace elements:
H3B03 2.86 mg/L
MnCl2.4H2O 0.36 mg/L
LiCl 0.31 mg/L
RbCl 0.071 mg/L
SrCl2.6H2O 0.152 mg/L
NaBr 0.016 mg/L
Na2MoO4.2H2O 0.063 mg/L
CuC12.2H2O 0.017 mg/L
ZnC12 0.013 mg/L
CoC12.6H2O 0.010 mg/L
KI 0.0033 mg/L
Na2SeO3 0.0022 mg/L
NH4VO3 0.00058 mg/L
Fe-EDTA solution 3.50 mg/L

Macro nutrients:
CaCl2.2H2O 294 mg/L
MgSO4.7H2O 123 mg/L
KCl 5.80 mg/L
NaHCO3 64.8 mg/L

Buffer nutrients
Na2SiO3.9H2O 10 mg/L
NaNO3 0.274 mg/L
KH2PO4 0.143 mg/L
K2HPO4 0.184 mg/L

Vitamins
Thiamine hydrochloride 0.075 mg/L
Cyanocobalamine (B12) 0.0010 mg/L
Biotin 0.00075 mg/L
Nominal and measured concentrations:
Nominal concentrations: 4.27, 9.39, 20.7, 45.5 and 100 mg/L
Arithmetic mean measured concentrations: 3.96, 8.91, 19.9, 45.9 and 95.6 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Stock cultures of Daphnia magna were maintained in glass vessels containing approximately 0.8 litres of Elendt M4 culture medium in a temperature-controlled laboratory at nominally 20 ± 2 °C.
- Aeration: No supplementary aeration was employed
- Renewal rate of test solution (frequency/flow rate): Daphnia were exposed to the test or control conditions for a period of 48 hours without renewal of test media.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- The first instar Daphnia were placed in groups of five, at random into glass dishes containing 100 mL of medium to give a loading of 20 mL medium per organism. The dishes were loosely covered.

TEST MEDIUM / WATER PARAMETERS
- Dilution medium: The test organisms were maintained and the tests conducted in Elendt M4 medium. The medium was prepared in ultra high purity (UHP) water produced by reverse osmosis.
- Alkalinity: 43 mg/L

OTHER TEST CONDITIONS
- Photoperiod: A photoperiod of 16 hours light 8 hours dark was maintained, with periods of subdued lighting at the beginning and end of each light phase.
- The temperature, pH and dissolved oxygen levels of control and test media were recorded at the start and at the end of the study.

EFFECT PARAMETERS MEASURED: Daphnia were considered to be immobile if they were unable to swim within approximately 15 seconds following gentle agitation of the test vessel.
The numbers of mobile, immobile and floating Daphnia were counted approximately 24 and 48 hours after the start of the study.

TEST CONCENTRATIONS
- Range finding study: The range finding test employed nominal test concentrations of 1, 10 and 100 mg/L. Based on the results of the range finding test, and the first main test, the definitive test employed nominal test concentrations of 4.27, 9.39, 20.7, 45.5 and 100 mg/L.

Note: A range finding test was conducted followed by two main tests. The first main test (originally planned as the definitive test) was repeated because floating Daphnia were observed at nominal concentrations of 9.39 mg/L and higher, which was unexpected since this had not been seen in the range finding test. As a result, a second main test (hereafter referred to as the definitive test) was conducted with five test concentrations plus a dilution medium control; the results of the definitive test were consistent with those of the first main test, and floating Daphnia were observed at nominal concentrations of 9.39 mg/L and higher.
Reference substance (positive control):
yes
Remarks:
potassium dichromate
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
27.2 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
3.96 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
45.9 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC0
Effect conc.:
8.91 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
In the definitive test, after 48 hours, the lowest measured concentration resulting in 100% immobility was 45.9 mg/L and the highest concentration at which no immobilization occurred was 8.91 mg/L. Four of the Daphnia exposed at 8.91 mg/L were floating (trapped at the surface of the medium) after 48 hours, but they remained mobile. A single Daphnia each at 19.9 and 45.9 mg/L was also floating, but these were immobile. These effects are considered to be treatment related based on the dose response.

Results with reference substance (positive control):
The results for the most recent test performed prior to this study indicated that its 48-hour EC50 to Daphnia magna was 0.7 mg/L; this was within the range typically obtained in this laboratory (0.3 to 0.8 mg/L).
Reported statistics and error estimates:
No additional data available

The measured concentrations of test item ranged between 91 and 102% of their nominal values in samples of freshly prepared and expired (48 hours old) media, giving overall mean measured levels of 3.96, 8.91, 19.9, 45.9 and 95.6 mg/L.

Table 6.1.3/1: Cumulative immobilisation

 

ST 06 C 05 mg/L

Cumulative numbers of immobile Daphnia

nominal

measured

24 hours

48 hours

R1

R2

R3

R4

Total

%

R1

R2

R3

R4

Total

%

0

nd

0

0

0

0

0

0

0

1

0

0

1

5

4.27

3.96

0

0

0

0

0

0

0

0

0

0

0

0

9.39

8.91

0

0

0

0

0

0

0

0

0

0

0

0#

20.7

19.9

0

0

0

0

0

0*

0

1

2

0

3

15**

45.5

45.9

5

3

2

2

12

60$

5

5

5

5

20

100**

100

95.6

5

5

5

5

20

100

5

5

5

5

20

100

 

 

R : replicate number.

nd : none detected (< 0.01 mg/l).

* : two Daphnia floating.

$ : four floating Daphnia immobile and five floating Daphnia mobile.

# : four floating Daphnia mobile.

** : one floating Daphnia immobile.

 

Evaluation of data:

EC50 values were calculated using the SAFEStat LD50 application (SAS 8.2.).

The “no observed effect concentration” (NOEC) was derived by direct inspection of the data on the immobility of the animals. An incidence rate of more than 10% is considered to be significant.

Validity criteria fulfilled:
yes
Conclusions:
The 48-hour EC50 for test item was 27.2 mg/L. No observed effect concentration was 3.96 mg/L.
Executive summary:

The acute toxicity of the test item to Daphnia magna was assessed under static exposure conditions according to OECD Guideline 202 and EU Method C.2 with GLP statement.

Groups of twenty Daphnia, less than 24 hours old, were exposed for 48 hours to test item, at nominal concentrations of 4.27, 9.39, 20.7, 45.5 and 100 mg/L. The test media were prepared in Elendt M4 medium by the direct addition of the test substance to the dilution medium; to aid dissolution, ultrasound treatment and overnight stirring were employed. The measured concentrations of test item ranged between 91 and 102% of their nominal values in samples of freshly prepared and expired (48 hours old) media, giving overall mean measured levels of 3.96, 8.91, 19.9, 45.9 and 95.6 mg/L.

 

Observations of the Daphnia in each control and test vessel were made after approximately 24 and 48 hours. After 48 hours, the lowest measured concentration resulting in 100% immobility was 45.9 mg/L and the highest concentration at which no immobilisation occurred was 8.91 mg/l. Four of the Daphnia exposed at 8.91 mg/L were observed to be floating (trapped at the surface of the medium) after 48 hours, but remained mobile. A single Daphnia at 19.9 and 45.9 mg/L were also observed to be floating, but were immobile.

 

The results for the most recent test performed prior to this study indicated that, 48-hour EC50 for potassium dichromate (reference item) to Daphnia magna was 0.7 mg/L; this was within the range typically obtained in this laboratory (0.3 to 0.8 mg/L). Water quality parameters such astemperature, pH, dissolved oxygen, total hardness and alkalinitywere determined to be within the acceptable limits. All validity criteria were fulfilled.

Under the test conditions, the 48-hour EC50 for test item was 27.2 mg/L. No observed effect concentration was 3.96 mg/L.

Description of key information

OECD Guideline 202, GLP, key study, validity 1:

48h-EC50 (Daphnia magna) = 27.2 mg/L based on measured concentrations.

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
27.2 mg/L

Additional information

The acute toxicity of the test item to Daphnia magna was assessed under static exposure conditions according to OECD Guideline 202 and EU Method C.2 with GLP statement.

Groups of twenty Daphnia, less than 24 hours old, were exposed for 48 hours to test item, at nominal concentrations of 4.27, 9.39, 20.7, 45.5 and 100 mg/L. The test media were prepared in Elendt M4 medium by the direct addition of the test substance to the dilution medium; to aid dissolution, ultrasound treatment and overnight stirring were employed. The measured concentrations of test item ranged between 91 and 102% of their nominal values in samples of freshly prepared and expired (48 hours old) media, giving overall mean measured levels of 3.96, 8.91, 19.9, 45.9 and 95.6 mg/L.