[No public or meaningful name is available]

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 - 24 Apr 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Due to the nature of the test item, analytical measurement is not possible.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

OECD 2004

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD guidance document no 23, Aquatic Toxicity Testing of Difficult Substances

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

THE DEPARTMENT OF HEALTH OF THE GOVERNMENT OF THE UNITED KlNGDOM, UK GLP Monitoring Authority

Test material

Test material information

Constituent 1

Reference substance name:

Vapour grown graphitic carbon fibre

Molecular formula:

C

IUPAC Name:

Vapour grown graphitic carbon fibre

Sampling and analysis

Analytical monitoring:

no

Remarks:

Due to the nature of the test item, analytical measurement is not possible.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Differential loading:
Since a limittest was conducted the only test item concentration was 100 mg/L. For each nominal concentration the required amount of homogenized sample was added to 500 mL of culture medium in an aspirator. The aspirators were mixed for 48 h at 21 to 23 °C and then allowed to separate for four hours. The aqueous phase, avoiding all settled and floating material, was drawn off and filtered using Whatman No. 1 filter paper. The resultant solution was used as the test exposure solution.
- Controls: medium without test item

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: CEFAS Laboratories, Lowestoft
- Feeding during test: No feeding durinng the test

ACCLIMATION
- Acclimation conditions (same as test or not): same; the water was adjusted to 18 - 22 °C, aerated until the dissoved oxygen concentration had reached a minimum of 3 mg/L and pH stabilised between 6 and 9.
- Type and amount of food: A suspension of Chlorella vulgaris. 1 mg/L organic carbon/litre of culture water until 24 h before the test initiation.
- Feeding frequency: each working day

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Less than 24 h

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

20.0 (Control and 100 mg/L)

pH:

8.0 - 7.5 (Control)
7.3 - 7.2 (100 mg/L)

Dissolved oxygen:

7.6 - 10.0 (Control)
8.8 - 9.6 (100 mg/L)

Nominal and measured concentrations:

Control and 100 mg/L (nominal loading rate)

Details on test conditions:

TEST SYSTEM
Test vessel:
- Type: open (covered with a transparent perspex sheet over the tops of the dishes to reduce evaporation)
- Material, size, headspace, fill volume: 60 mL glass beaker, 25 mL test volume, 35 mL headspace, to limit the aerial contamination of the test vessels and reduce evaporation losses, a transparent perspex sheet was placed over the tops of the dishes.
- 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 ISO water
- Culture medium different from test medium: Culture medium and test medium the same
- Intervals of water quality measurement: Water qualities , pH and dissolved oxygen determinations, on pooled replicates for the test and control solution were carried out immediately prior to initiating the test and at the end of the 48 h test period, temperature was recorded at 0, 24 and 48 h.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light and 8 h dark

EFFECT PARAMETERS MEASURED: The number of immobilised Daphnia was recorded after 24 and 48 h h periods.

RANGE-FINDING STUDY
- Test concentrations: 0, 0.1, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: No Daphnia was immobile up to and including 100 mg/L after 48 h.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No abnormal behaviour was observed.
- Mortality of control: No mortality was observed.

Results with reference substance (positive control):

- EC50: 0.88 mg/L (95% confidential limit: 0.76 - 1.03 mg/L)

Reported statistics and error estimates:

Where possible the EL50 values are shown graphically with calculated with 95% confidence limits according to the methods of ToxCalc tm Version 5.0 "Comprehensive Toxicity Data Analysis and Database Software"

Any other information on results incl. tables

Biological results:

The 48 h EL50 value of the test item to Daphnia magna was estimated to be greater than 100 mg/L. The highest no observed effect loading rate (NOELR) after 48 h was 100 mg/L.

Table 1: Cumulative immobilisation

Loading rate	Number immobilized		% Immobilisation
[mg/L]	24 h	48 h	24 h	48 h
0	0	0	0	0
100	0	0	0	0

 Table 2: Observation:

Loading rate	Recorded observations
[mg/L]	24 h	48 h
0	NS	NS
100	NS	NS

NS no signs of abnormal behavior

Table 3: EL50 and NOELR values (based on the nominal loading rate)

Period of exposure (h)	EL50 value	95% confidence limits	NOELR
0	> 100 mg/L	Not possible to determine	100 mg/L
100	> 100 mg/L	Not possible to determine	100 mg/L

Table 4: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	no immobile Daphnia was observed	Yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	Oxygen concentration was ≥ 3 mg/L	Yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.