[No public or meaningful name is available]

Short-term toxicity to aquatic invertebrates

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:

11 January 2007 to 31 July 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Concentrations: 22 mg/L, 46 mg/L, and 100 mg/L (based on loading rates)

For the characterization of the WAFs and the determination of the actual test item concentrations the following samples were taken:

Just before the start of the test:
- duplicate samples from each test medium (without daphnids)
- duplicate samples from the control (without daphnids)

After 48 hours:
- duplicate samples from each test medium
(stability samples) - duplicate samples from the control

For the 48-hour stability samples, additional flasks with adequate volumes of the freshly
prepared test media of all test concentrations and the control were incubated during the test
period under the same conditions as in the actual test (but without daphnids).

The concentrations of the test item were analytically measured in all test medium samples
taken at the start of the test. From the samples taken at the end of the test, the duplicate
samples from the test media with loading rates of 22, 46 and 100 mg/L were analyzed. The
stability samples taken from the lowest loading rates of 4.6 and 10 mg/L were not analyzed,
since these loading rates were below the 48-hour NOEC, determined in this test.

From the control samples, one of the duplicate samples was analyzed from each of the
sampling times. All the samples were analyzed immediately after sampling.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method:

For preparation of the Water Accommodated Fractions (WAFs), individual dispersions of the test item with the loading rates of 4.6, 10, 22, 46 and 100 m/L were prepared. The dispersions were stirred for three hours to dissolve a maximum amount of the different compounds of the test item in the dispersion. Thereafter, the dispersions were filtered through membrane filters (0.5 µm) and the undiluted filtrates were tested as WAFs. Due to technical reasons, the WAF with the lowest loading rate of 4.6 mg/L was prepared as a dilution of the WAF with the loading rate of 10 mg/L. The test media were freshly prepared just before introduction of the daphnids. Exposures are expressed in terms of the original concentration of test item in water at the start of the mixing period (loading rate) irrespective of the actual concentration of the test item in the WAF. The selection of the loading rates for the test was based on the results of a range-finding test (non-GLP). Loading rates above 100 mg/L were not specified in accordance with test guidelines.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Common name: Daphnia magna
- Source: in-house laboratory cultures
- Age at study initiation (mean and range, SD): less than 24 hours old

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mmol/L

Test temperature:

20°C at start and end of test

pH:

7.7 – 8.0

Dissolved oxygen:

8.0 - 8.9 mg/L

Nominal and measured concentrations:

Range finding test: Not specified (non-GLP test).
Definitive test: Nominal 4.6, 10, 22, 46, and 100 mg/L

Details on test conditions:

Range finding test: Not specified (non-GLP test).
Definitive test:

TEST SYSTEM
- Test vessel: 100 mL glass beaker
- Type: open
- Material, size, headspace, fill volume: 50 mL test preparation
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted test water. Analytical grade salts were dissolved into purified water.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light 8 hours darkness (30 transition periods).
- Light intensity: 490 – 650 lux

EFFECT PARAMETERS MEASURED :
The criterion of effect used was that Daphnia magna were considered to be immobilized if they were unable to swim for approximately 15 seconds after gentle agitation.

TEST CONCENTRATIONS
- Definitive test:
Based on the results of a non-GLP range finding test, loading rates of 4.6, 10, 22, 46 and 100 mg/L were used, using a stirring period of 3 hours. The stirring period used was determined by a pre-test, testing periods of 3, 24, and 96 hours.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

87 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

After 24 and 48 hours of exposure, no immobilized daphnids were determined in the control.

- Test media: No remarkable observations were made concerning the appearance of the test media. All test media were clear solutions throughout the entire test duration.

Chemical analysis of the test preparations at 0 and 48 hours showed an average recovery rate of 86% of the spiked values (n = 3). The LOQ was found to be 0.433 g/L. With a factor of 0.2 from the sample dilution, this gave an LOW of approximately 0.09 mg/L of the test item results. The biological control samples and analysed analytical blank (test water) did not affect the GC-chromatogram at the retention time of the test item. The average concentrations found in the treatment samples at test start ranged from 2.59 mg/L to 36.3 mg/L and at test end from 7.06 mg/L to 21.8 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

In an OECD 202 study in Daphnia magna the 24 hour EC50 value was 87 mg/L. The 24 hour EC0 was 22mg/L/ and the 24 hour EC100 was above the loading rate of 100 mg/L.

The 48 hour EC50 value was calculated to be 56 mg/L. The 48 hour EC0 and the 48 hour NOEC were 22 mg/L. The 48 hour EC 100 was above the loading rate of 100 mg/L.

Executive summary:

The acute toxicity of the test substance to Daphnia magna was determined in a
48-hour static test according to the EU Commission Directive 92/69/EEC, Part C.2 (1992) and the OECD Guideline for Testing of Chemicals, No. 202 (2004).

In order to assess the toxicity of the substance to daphnia, water accommodated fractions (WAFs) with the loading rates of 4.6, 10, 22, 46 and 100 mg/L were tested. Additionally, a control (test water without test item) was tested in parallel. The test method was based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000).

For preparation of the WAFs, individual dispersions of the test item with the loading rates as mentioned above were prepared. The dispersions were stirred for 3 hours to dissolve a maximum amount of the different compounds of the test item in the dispersion. Thereafter, the dispersions were filtered through membrane filters (0.45 µm) and the undiluted filtrates were tested as WAFs. Due to technical reasons, the WAF with the lowest loading rate of 4.6 mg/L was prepared as a dilution of the WAF with the loading rate of 10 mg/L.

At the start of the test, the measured test item concentrations (based on a main component of the test item) in the test media with the loading rates of 4.6, 10, 22, 46 and 100 mg/L were 2.6, 5.6, 9.7, 20 and 36 mg/L, respectively. At the end of the test, the measured concentrations in the test media with the loading rates of 22, 46 and 100 mg/L were 7.1, 13 and 22 mg/L, respectively.

Since water accommodated fractions of the test item were tested, all reported biological results were based on the loading rates of the test item.

The biological test results (based on the loading rates) were as follows:
– 24-hour EC50: 87 mg/L
95% confidence limits: 62–120 mg/L

– 24-hour EC0: 22 mg/L

– 24-hour EC100: >100 mg/L

– 48-hour EC50: 56 mg/L
(95% confidence limits could not be determined)
– 48-hour EC0 and
48-hour NOEC: 22 mg/L
– 48-hour EC100: >100 mg/L

Description of key information

In an OECD 202 study in Daphnia magna the 24 hour EC50 value was 87 mg/L. The 24 hour EC0 was 22mg/L/ and the 24 hour EC100 was above the loading rate of 100 mg/L.

The 48 hour EC50 value was calculated to be 56 mg/L. The 48 hour EC0 and the 48 hour NOEC were 22 mg/L. The 48 hour EC 100 was above the loading rate of 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

56 mg/L