Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012-06-12 tü 2012-06-30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD Guideline; EU Method; GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Duplicate samples from the freshly prepared test media of all test concentrations and the control were taken at the start of the test.
For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the test media of all test concentrations and the control were collected at the end of the test (after 48 hours) by pouring together the contents of the test beakers of each treatment.

Test solutions

Vehicle:
no
Details on test solutions:
The test medium of the highest test concentration of nominal 10000 mg test item/L was prepared by dissolving 8019.2 mg test item into 802 mL of test water by intense stirring for 10 minutes. Adequate volumes of this test medium were diluted with test water to prepare the test media of the other desired test concentrations.The test media were prepared just before introduction of the daphnids (= start of the test).

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Species: Daphnia magna (Straus), clone 5
Age at Test Start: From 2.25 to 18.5 hours old
Sex: Female
Origin: The daphnids introduced in the test were taken from our in house laboratory culture.
Breeding Conditions: The daphnids were bred in the laboratories of IBACON under similar temperature and light conditions as used in the test. The cultivation of the parental daphnids was performed in the same reconstituted water as the test water used in the test. The test organisms were not first brood progeny. The daphnids in the stock culture were fed at least on all working days with green algae (Desmodesmus subspicatus) freshly grown in the laboratories of IBACON.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
Water Hardness: 2.5 mmol/L (= 250 mg/L) as CaCO3
Test temperature:
19 to 20 °C at test start;
19 °C at test end

pH:
8.2 at test start;
7.8 to 7.9 at test end
Dissolved oxygen:
8.7 to 9.1 mg/L at test start;
8.4 to 8.7 mg/L at test end

Nominal and measured concentrations:
Test Concentrations: 10000, 5000, 2500, 1250 and 625 mg test item/L and a control.
Details on test conditions:
Test Environment: Controlled environment room
Measurement of pH, Dissolved
Oxygen and Water Temperature:
The water temperature, pH-values and dissolved oxygen concentrations were determined at test start and test end in each treatment group.
Water Temperature: 19 to 20 °C at test start;
19 °C at test end
pH-Values: 8.2 at test start;
7.8 to 7.9 at test end; and thus the pH-value did not vary by more than 1.5 units (see Table 5)
Dissolved Oxygen Concentration:
8.7 to 9.1 mg/L at test start;
8.4 to 8.7 mg/L at test end
Light Regime: 16 h light : 8 h dark
Light Intensity: The light intensity was 900 - 1130 lux (measured once during the test).

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
7 467 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 95 % CL: 3991- 41596
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
3 267 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 95 % CL: 1800-7745
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
2 500 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
5 000 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
After 24 hours of exposure no immobilisation of the test animals was observed in the control and the concentrations up to and including nominal 5000 mg test item/L. At the highest test concentration of nominal 10000 mg test item/L 6 daphnids were immobile after 24 hours test duration.
At the end of the test the toxicity of the test item to Daphnia magna had increased. After 48 hours of exposure no immobilisation of the test animals was observed in the control and up to and including the test item concentration of nominal 2500 mg test item/L. At the test item concentration of nominal 5000 mg test item/L eleven animals, corresponding to 55 %, were immobile after 48 hours of test duration. At the highest test concentration of nominal 10000 mg test item/kg fifteen animals, corresponding to 75 % of the introduced Daphnia, were immobile until test end.

Any other information on results incl. tables

Summary of Biological Results

Nominal Concentration

% of immobilised daphnids after

[mg test item/L]

24 hours

48 hours

Control

0

0

625

0

0

1250

0

0

2500

0

0

5000

0

55

10000

30

75

EC50[mg/L]:

 > 10000 

 7467 

95 % CI [mg/L]:

 n.d. 

 3991 - 41596 

EC20[mg/L]:

 n.d. 

 4339 

95 % CI [mg/L]:

 n.d. 

 2465 - 13234 

EC10[mg/L]:

 n.d. 

 3267 

95 % CI [mg/L]:

 n.d. 

 1800 - 7745 

NOEC [mg/L]:

 5000 

 2500 

LOEC [mg/L]:

 10000 

 5000 

Values refer to nominal test concentrations.
n.d. = not determinable
CI: Confidence interval

NOEC and LOEC were determined directly from the raw data.

Analytical Results

Determination of the Test Item:

Based on the results of GC measurements the concentration of the test item was determined using a calibration curve.

Calibration Range:

The calibration curve was split in a low and a high concentration range.

Low range:     0.5 to 5 mg test item/L

High range:     0.75 to 7.5 mg test item/L

Linearity of Response:

Correlation of peak area of different standard solutions with their corresponding concentrations, using a linear regression

Regression Coefficient (r2):

At least 0.9976


Calibration Curves:

Low range:     y = 17311 * x + 2255

High range:     y = 18464 * x + 348

Limit of Detection:

0.125mg test item/L

Limit of Quantification:

2000 mg test item/L

85 % (n = 5, RSD 18 %)

Mean Recovery in the Fortified Samples:

 

88 % (n = 10, RSD 13 %)

Mean Recovery in the Test Samples:


Freshly prepared:       99 % (n = 6, RSD 4 %)

Aged test media:        99 % (n = 6, RSD 5 %)

 

 

 

Summary of Analytical Results

sample description % of RSD
[mg test item/L] nominal1 [%] n
       
control n.a. n.a. 2
625 n.d. - -
1250 n.d. - -
2500 96 4 4
5000 101 2 4
10000 99 5 4

1mean value of all measured samples per treatment group
RSD: relative standard deviation per treatment group
n.d. not determined since below NOEC

n: number of analysed samples
n.a.: not applicable

 

 

 

The limit of detection and the limit of the quantification of the analytical method were 0.125 and 2000 mg test item/L, respectively.

At the start of the test 99 % of the nominal test concentration was found (average of test concentrations of nominal 2500 to 10000 mg test item/L). After 48 hours test duration, 99 % of the nominal value was determined (average of test concentrations of nominal 2500 to 10000 mg test item/L). During the test the daphnids were exposed to a mean of 99 % of nominal. Therefore, all reported results refer to nominal concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The toxic effect of the test item Tetraethyleneglycoldimethylether to Daphnia magna was assessed in a static dose-response test. The 48-hour NOEC was determined to be 2500 mg test item/L. The 48-hour LOEC was determined to be 5000 mg test item/L and the 48-hour EC50 value was calculated to be 7467 mg test item/L.
Executive summary:

The acute toxicity of the test item to Daphnia magna in a static 48-hour immobilisation test was determined and based on the procedures indicated by the following internationally accepted methods:

- OECD Guidline No 202

- EU Method C.2

The influence of the test item on the mobility of Daphnia magna was estimated on young daphnids (< 24 hours old), which were exposed in a static test to the test item for 48 hours, added to test water at a range of concentrations. Under otherwise identical test conditions, different concentrations of the test item result in different percentages of daphnids being no longer capable of swimming at the end of the test.

Test concentrations: 10000, 5000, 2500, 1250 and 625 mg test item/L and a control.

The quantification of the test item was performed using gas chromato-graphy (GC-MS-method). The limit of detection and the limit of the quantification of the analytical method were 0.125 and 2000 mg test item/L, respectively.

At the start of the test 99 % of the nominal test concentration was found (average of test concentrations of nominal 2500 to 10000 mg test item/L). After 48 hours test duration, 99 % of the nominal value was determined (average of test concentrations of nominal 2500 to 10000 mg test item/L). During the test the daphnids were exposed to a mean of 99 % of nominal. Therefore, all reported results refer to nominal concentrations.

The toxic effect of the test item Tetraethyleneglycoldimethylether toDaphnia magnawas assessed in a static dose-response test. The 48-hour NOEC was determined to be 2500 mg test item/L. The 48-hour LOEC was determined to be 5000 mg test item/L and the 48-hour EC50value was calculated to be 7467 mg test item/L.

This study is classified acceptable and satisfies the guideline requirements for daphnia acute test studies.