[No public or meaningful name is available]

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 5 March to 9 March 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 203 (Fish, Acute Toxicity Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

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, 24, 48, 72 and 96 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).

Test solutions

Vehicle:

yes

Details on test solutions:

The test concentration of 0.0015 mg/l was the highest attainable test concentration due to the limited solubility of the test material in water and auxiliary solvent (dimethylformamide), and having due regard for the amount of auxiliary solvent permitted in the test under the OECD Guidelines.

In a range-finding test fish were exposed to a nominal test concentration of 0.0015 mg/l. A single test concentration was used as results from the range-finding test for the Acute Toxicity to Daphnia magna study (Safepharrn Laboratories Project Number: 0656/0328) indicated that toxicity was not expected at this concentration. The test material was prepared using a preliminary solution in dimethylformamide.

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 freshly prepared media at 0, 24, 48 and 72 hours showed measured test concentrations of 94% to 136% of the nominal value, indicating that the test system was correctly dosed. Analysis of the freshly prepared centrifuged test preparations at 0, 24, 48 and 72 hours showed measured test concentrations of 31% to 50% of the nominal value.

Analysis of the untreated old test media samples at 24, 48, 72 and 96 hours showed concentrations of 53% to 108% of nominal whilst analysis of the corresponding centrifuged samples showed measured test concentrations of 24% to 52% of the nominal value.

The low measured concentrations in the centrifuged samples for both the freshly prepared and old media indicated that not all the test material present was dissolved. Pre-study work showed that prolonged stirring did not increase the dissolved test material concentration. There was also a general slight decline in the measured test concentrations of the centrifuged test samples over the test period, indicating a decrease in concentration of the soluble test material.

Given that the preliminary stability analyses conducted indicated that the test material was stable in dechlorinated tap water over the media renewal period this decline in measured concentrations was considered to be due to possible adsorption of the test material to glassware as the test material was shown to have a log Koc of 4.57 (Safepharrn Laboratories Project Number 0656/0322).

The inconsistency with the water solubility value of 0.00151 mg/l from the study to determine the water solubility (Safepharm Laboratories Project Number 0656/0322) of the test material was considered to be due to differences in the diluents used, as dechlorinated tap water has a greater dissolved salt/mineral concentration that glass double distilled water used for the water solubility test which may have affected the solubility of the material.

Given this general decline in measured test concentrations it was considered justifiable to base the results on the time weighted mean measured test concentrations of the centrifuged test media to give a "worst case" analysis of the data.

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Length at study initiation: 4.5 cm (sd = 0.4)
- Weight at study initiation: 1.32 g (sd = 0.42)
- Feeding during test (discontinued approximately 24 hours prior to the start of the definitive test)
- Food type: Commercial trout pellets


ACCLIMATION
- Acclimation period: 12 days
- Acclimation conditions: Same as test
- Type of food: Commercial trout pelletes
- Health during acclimation (any mortality observed): No mortality in the 7 days prior to the start of the test

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Test conditions

Hardness:

140 mg/l as CaCO3

Test temperature:

Approximately 14ºC

pH:

7.8 - 8.0

Dissolved oxygen:

9.4 - 10.5 mg O2/l

Nominal and measured concentrations:

Nominal: 0.0015 mg/l
Mean measured: 0.00056
See also 'Details on test solutions'

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: Covered
- Material, size, headspace, fill volume: 20 litre, glass
- Aeration: Via narrow bore glass tubes
- Renewal rate of test solution: Test solutiond replaced every 24 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2


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


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


EFFECT PARAMETERS MEASURED: Mortality, after 3, 6, 24, 48, 72, 96 hours

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.001 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Absence of any sublethal effects

Results with reference substance (positive control):

Not conducted due to ethical reasons