Registration Dossier

Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
3 May 2005 and 7 May 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted in 2005 according to OECD Method 203 and EU Annex V test C.1 and in accordance with GLP. Study material is well characterized.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2006

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.1 (Acute Toxicity for Fish)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test material is a extremely light tan colored powder which was received at testing laboratory on 15 February 2005 and stored at room temperature in the dark.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Water samples were taken from the control and each replicate test vessel at 0 (fresh media), 24 and 96 hours (old media) for quantitative analysis.
Duplicate samples and samples at 24 (fresh media), 48 and 72 hours (fresh and old media) were taken and stored at approximately -20°C for further analysis if necessary.

Test solutions

Vehicle:
no
Details on test solutions:
The test material was dissolved directly in dechlorinated tap water, ultrasonicated for approximately 120 minutes, and the volume adjusted to 2 litres to give a 2.00 g/L stock solution. The stock solution was cooled to approximately 14°C and thoroughly mixed prior to being diluted to the testing dose of 100 mg/L test concentration.

Test organisms

Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
Fish were maintained in a glass fibre tank with a "single pass" water renewal system and acclimatised for 14 days.

TEST ORGANISM
- Common name: juvenile rainbow trout (Oncorhynchus mykiss).
- Source: Fish were obtained from Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Length at study initiation (length definition, mean, range and SD): fish had a mean standard length of 4.1 cm (sd = 0.1) at the end of the definitive test.
- Weight at study initiation (mean and range, SD): mean weight of 1.21 g (sd = 0.07) at the end of the definitive test. Based on the mean weight value this gave a loading rate of 0.42 g bodyweight/litre.
- Feeding during test- Food type: commerical trout pellets

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food:commercial trout pellets
- Health during acclimation (any mortality observed): zero

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
96 h

Test conditions

Hardness:
Laboratory tap water was dechlorinated partly softened to give a total hardness of approximately 100 mg/L as CaC03.
Test temperature:
Maintained at approximately 14 C throughout the study
pH:
For fresh media ranged from 7.4 to 7.7 throughout the study
For old media pH ranged from 7.7 to 8.2 thoughout the study
Dissolved oxygen:
dissolved oxygen concentration expressed as a percentage of Air Saturation Value (ASV)
For fresh media ranged from 89 to 92 %
For old media ranged from 91 to 96 %
Nominal and measured concentrations:
Analysis of the test preparations at 0, 24 and 96 hours showed measured test concentrations to range from 96% to 99% of nominal and so it was considered justifiable to estimate the LC50 values in terms of the nominal test concentrations only.
Details on test conditions:
In the range-finding test 3 fish were used and in the definitive study 7 (seven) fish were placed in each test vessel glass fibre tank at random in the test preparations. For the range-finding test and the definitive test 20 litre glass fibre exposure vessels were used for each test concentration ( control, and 100 mg/L). The test vessels were then covered and maintained at approximately 14°C in a temperature controlled room with a photoperiod of 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods for a period of 96 hours. The test vessels were aerated via narrow bore glass tubes. The fish were not individually identified and received no food during exposure..
After 3, 6, 24, 48, 72 and 96 hours any mortalities or sub-lethal effects of exposure were determined by visual inspection of the test fish.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Details on results:
Range finding study:
-There were no sub-lethal effects of exposure during the range-finding test.
-The results showed no mortalities at the test concentration of 100 mg/L.

Definitive Study:
-There were no mortalities in 14 fish exposed to a test concentration of 100 mg/L for a period of 96 hours.
-The results of the definitive test showed the highest test concentration resulting in 0% mortality to be greater than or equal to 100 mg/L, the lowest test concentration resulting in 100% mortality to be greater than 100 mg/L and the No Observed Effect Concentration (NOEC) to be 100 mg/L. The No Observed Effect Concentration is based upon zero mortalities and the absence of any sub- lethal effects of exposure at this concentration

Reported statistics and error estimates:
The 3, 6, 24, 48, 72 and 96-Hour LC50 values and associated 95% confidence limits will be calculated using the trimmed Spearman-Karber method. All LC50 (or values will be rounded to two significant figures).

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The acute toxicity of the test material to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated and gave a 96-Hour LC50 of greater than 100 mg/L. Correspondingly the No Observed Effect Concentration was 100 mg/L.
Executive summary:

A study was performed to assess the acute toxicity of the test material to rainbow trout (Oncorhynchus mykiss). This key aquatic toxicity study was assigned reliability rating of 1 (reliable without restriction) and the results are considered valid.

Following a preliminary range-finding test fish were exposed, in two groups of seven, to an aqueous solution of the test material, at a single concentration of 100 mg/L for a period of 96 hours at a temperature of approximately 14 C under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours.

The 96-Hour LC50 based on nominal test concentrations was greater than 100 mg/L and correspondingly the No Observed Effect Concentration was 100 mg/L. It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/L.

Analysis of the test preparations at 0, 24 and 96 hours showed measured test concentrations to range from 96% to 99% of nominal and so the results are based on nominal test concentrations only.