[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:

From 5 February to 7 February 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, GLP compliant; no restrictions, fully adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Water samples were taken from the solvent control and each replicate test vessel at 0 and 48 hours for quantitative analysis.

Two samples of the solvent control and each replicate were taken at each occasion. One sample was analysed untreated and one sample after centrifugation (40000 g for approximately 30 minutes). Further samples (in duplicate) were taken and stored at approximately -20°C for further analysis if necessary.

Test solutions

Vehicle:

yes

Details on test solutions:

During the definitive test samples of the test preparations were analysed untreated and following centrifugation at 40000 g for 30 minutes. The untreated samples indicated the total amount of test material present in the test preparations whilst the centrifuged samples indicated the amount of soluble and hence bioavailable test material present.

Analysis of the untreated test preparations throughout the test showed measured test concentrations of 101% to 126% of the nominal value, indicating that the test system was correctly dosed. Analysis of the freshly prepared centrifuged test preparations at 0 hours showed measured test concentrations of 69% to 70% of the nominal value. Analysis of the centrifuged samples at 48 hours showed measured test concentrations of 46% to 51% of the nominal value. The low measured concentrations in the centrifuged samples at both 0 and 48 hours indicated that not all the test material present was dissolved. There was also a slight decline in the measured test concentrations of the centrifuged test samples over the test period, indicating that the soluble test material may have also been unstable in the test diluent. The inconsistency with the water solubility value of 0.00151 mg/l from the study to determine the water solubility of the test material (Safepharm Laboratories Project Number 0656/0322) was considered to be due to differences in the diluents used, as reconstituted water used in the Daphnia magna test had a far greater dissolved salt/mineral concentration than glass double distilled water used for the water solubility test which affected the water solubility.

Given that lower values were shown for the centrifuged test material preparations and a slight decline was shown in these measured test concentrations over the test period it was considered justifiable to base the results on the geometric mean measured test concentrations of the centrifuged test media in order to give a "worst case" analysis of the data.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Adult Daphnia were maintained in polypropylene vessels containing approximately 2 litres of reconstituted water in a temperature controlled room at approximately 20°C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk
transition periods. Each culture was fed daily with a suspension of algae (ChIarella sp.). Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Test conditions

Hardness:

250 mg/l as CaCO3

Test temperature:

Approximately 20ºC

pH:

7.8 - 8.0

Dissolved oxygen:

8.7 - 8.9 mg O2/l

Nominal and measured concentrations:

Nominal: 0.0015 mg/l
Mean measured: 0.00087 mg/l
See also 'Details on test solutions'

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: covered
- Material, size, headspace, fill volume: 250 ml glass jars
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water


OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 16 hours light, 8 hours dark

SOLVENT CONTROL
100 µl/l DMF


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, after 24 and 48 hours

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 0.001 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.001 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Results with reference substance (positive control):

Sensitivity to control substance
EC50 (24 h) : 1.2 mg/l
EC50 (48 h) : 0.85 mg/l