Registration Dossier

Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Deviations:
no
Remarks:
Conducted according to guideline in effect at time of study conduct
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Purity: 22.82% solids in water

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
One sample plus a back-up sample was received from the single test chamber at all test concentrations, including the dilution water control, from newly prepared test solutions on days 0 and 2 and from old tests solutions on days 2 and 4 of the test. In addition to the neat test solution samples, one sample plus a back-up sample was received of test solutions diluted 1:3 test solution:methanol (5 mL test solution + 15 mL methanol) from each test concentration, including the dilution water control, from newly prepared test solutions on days 0 and 2, and from old test solutions on days 2 and 4 of the test. All samples and back-up samples were stored refrigerated when not in use.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION:
Test substance solutions were prepared by direct addition of the test substance to dilution water, test facility well water. The dilution water control and test solutions were prepared by adding the appropriate amount of test substance to dilution water in 26-L stainless steel tanks (final volume 15 L) and stirring for approximately 2 hours. Based on visual observations, the dilution water control was clear and colourless and lacked precipitate at solution preparation on days 0 and 2 and through the duration of the test. The nominal 32.9 mg/L test concentration was clear with no colour, the nominal 65.7 and 131 mg/L test concentrations were slightly cloudy, and the nominal 263 and 526 mg/L test solutions were cloudy at solution preparation on days 0 and 2. All test concentration solutions had undissolved test substance present and a surface film, and all test concentration solutions except the nominal 35.7 mg/L had undissolved test substance on the surface at solution preparation on days 0 and 2.

Dilution water originated from the testing laboratory well, which is 480-feet deep and is cased and sealed to bedrock. The hardness of the well water is adjusted to approximately 100-140 mg/L as CaCO3 by the flow-proportioned addition of CaCl2. The well water is then aerated, passed through a green sand filter to remove iron, and filtered through 50-, 10-, and 3.0-μm cartridge filters to remove particulates. The water is heated or chilled as appropriate and distributed through aged polyvinyl chloride piping. Dilution water quality was acceptable based on OECD 203 guideline specifications, and no quantifiable concentrations of pollutants and pesticides were present in the most recent semiannual dilution water analysis.

Test organisms

Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
Rainbow trout, Oncorhynchus mykiss, were purchased from Thomas Fish Company, Anderson, California and were 42 days old at test start. The organisms were held at the testing facility in a 272-L, circular, fiberglass holding tank (84-cm diameter, 49-cm deep) for 18 days in test facility well water. During the 7-day period preceding the test, waterbath temperatures ranged from 11.8 to 12.8°C (mean 12.3°C). The test organisms were fed freshly-hatched, live brine shrimp (San Francisco Bay Brand, Newark, California, U.S.A.) and AquaMax® Starter Fingerling 300 5D03 (PMI® Nutrition International, LLC) 3 times weekly. Feed is analysed after receipt to assure that contaminants are not present at levels that would be expected to affect the scientific integrity of the study. Less than 2% mortality in the culture was observed during the 48 hours prior to use for testing.

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h

Test conditions

Hardness:
EDTA hardness: 123 to 124 mg/L as CaCO3
Test temperature:
12.2 - 12.9°C
pH:
7.9 - 8.4
Dissolved oxygen:
8.6 - 10.5 mg/L
Salinity:
freshwater
Nominal and measured concentrations:
Nominal Active Substance Total Solids concentrations of 7.5, 15, 30, 60, and 120 mg/L (equivalent to 35.7, 65.9, 131, 263, and 526 mg/L test substance based on 22.82% purity by analysis) were chosen for the definitive test based on the results of a preliminary rangefinding study.
Mean, Measured Total Solids concentrations: 0, 6.45, 12.8, 27.6, 47.1, and 110 mg
Details on test conditions:
Test chambers were stainless steel aquaria [30 (length) x 30 (width) x 30 (height) cm], which held approximately 15 L of test solution (26-L maximum volume; 17.5-cm test solution depth). One test chamber was used per test concentration with 10 test organisms in each chamber (10 test organisms per concentration). The test solutions were renewed after approximately 48 hours. The test chambers were covered with a glass plate during the test. Random numbers were used to assign the position of test chambers in the waterbath. A sign was placed above the waterbath identifying the definitive test by its unique study description, which included the work request and service code. The individual test chambers were labelled with total solids concentration.

A recirculating waterbath was used to maintain mean temperature in the test chambers during the test at approximately 12°C. In addition, a continuously-recording thermometer was used to check for temperature variation in the waterbath. A photoperiod of 16 hours light and 8 hours darkness was employed, which included 30 minutes of transitional light preceding and following the 16-hour light interval.

Dissolved oxygen concentration, pH, and temperature were measured in the single test chamber of the dilution water and test substance concentrations. These measurements were taken at test start, and daily thereafter including in both new and old test solutions at 48 hours. Total alkalinity, EDTA hardness, and conductivity were measured in the dilution water control and highest test substance concentration at the test start. Test solutions were not aerated during the test. Test solutions were carbon-filtered prior to disposal at test end.

Total solids concentrations were verified by chemical analysis in the single test chamber of the dilution water control and test substance concentrations at test start, at test substance renewal (from both new and old solutions), and at test end.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 110 other: mg total solids/L
Nominal / measured:
meas. (arithm. mean)
Basis for effect:
mortality
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 526 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality
Details on results:
The highest nominal concentration of the test substance causing no mortality at test end was 526 mg/L, corresponding to a mean, measured concentration of 110 mg total solids/L. The lowest nominal concentration causing 100% mortality at test end was greater than 526 mg/L, corresponding to a mean, measured concentration of greater than 110 mg total solids/L. The 96-hour LC50 values, based on mortality and nominal test substance concentrations and mean, measured total solids concentrations, were greater than 526 mg/L and greater than 110 mg total solids/L, respectively.

During the test, the dilution water control was clear with no colour and lacked precipitate. Based on visual observations, the nominal 35.9, 65.7, and 131 mg/L test solutions were clear with no colour, had a surface film, and had undissolved test substance settled on the bottom of the test chambers in old test solutions after 24 and 48 hours. The nominal 263 and 526 mg/L test solutions were slightly cloudy and cloudy, respectively, had a surface film, and had undissolved test substance settled on the bottom of the test chambers and on the test solution surface in old solutions after 24 and 48 hours.
Reported statistics and error estimates:
The 96-hour LC50 values were not calculated because survival was greater than 50% in all test solutions, and are reported as greater than the high test concentration

Any other information on results incl. tables

No mortality or sublethal effects were seen in the dilution water control or test solution organisms. Exposure of test organisms to mean, measured total solids concentrations of 6.45, 12.8, 27.6, 47.1, and 110 mg total solids/L resulted in 0, 0, 0, 0, and 0% mortality, respectively, at the end of 96 hours. All water quality parameters were within acceptable limits during the exposure.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
This study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).
96-hour LC50, based on mean, measured concentrations and mortality > 110 mg total solids /L.
96-hour LC50, based on nominal concentrations > 526 mg/L .
Executive summary:

The acute toxicity of the test substance to unfed fingerling rainbow trout, Oncorhynchus mykiss, was determined in an unaerated, 96-hour, static-renewal toxicity test. The test was conducted in accordance with the OECD Guideline for the Testing of Chemicals: 203. The test substance contains 22.82% total solids by analysis. The study was conducted with 5 concentrations and a dilution water control at a mean temperature of 12.6°C. The test solutions were renewed after approximately 48 hours. One test chamber was used per test concentration with 10 test organisms in each chamber (10 test organisms per concentration).

Exposure of test organisms to nominal concentrations of 32.9, 65.7, 131, 263, and 526 mg/L, equivalent to mean, measured total solids concentrations of 6.45, 12.8, 27.6, 47.1, and 110 mg total solids/L, resulted in 0, 0, 0, 0, and 0% mortality, respectively, at the end of 48 hours. No mortality or sublethal effects were observed in the dilution water control test organisms. The highest mean, measured concentration causing no mortality at test end was 110 mg total solids/L. The lowest mean, measured concentration causing 100% mortality at test end was greater than 110 mg total solids/L. The 96-hour LC50 values, based on mortality and nominal test substance concentrations and mean, measured concentrations of total solids, were greater than 526 mg/L and greater than 110 mg total solids/L, respectively.