Registration Dossier

Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15 December 2016 - 30 December 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to
Guideline:
other: Ministry of environmental protection of the people's Republic of China, The Guidelines for the Testing of Chemicals-Effects on Biotic Systems, 2013, 203 Fish, Acute Toxicity Test.
Version / remarks:
2013
Deviations:
no
Qualifier:
according to
Guideline:
other: GB/T 29763-2013 Chemicals-Rare Minnow (Gobiocypris rarus) acute toxicity test.
Version / remarks:
2013
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
Appearance: colourless or light yellow viscous liquid
Storage conditions: at room temperature, container tightly closed, flushed with nitrogen.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Sampling method: 30 mL test solution was taken from each vessel at the beginning of the test, before and after each renewal and at the end of the test.
- Sample storage conditions before analysis: not applicable, samples were analysed directly without storage.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: direct addition to the test medium; a nominal concentration of 100 mg/L of the test substance was prepared and stirred (via a magnetic stirrer) in the dark for 24 h followed by filtration using a 0.45µm nitrocellulose membrane to make a saturated solution of the test substance in test water.
- Controls: a blank control containing only test water.

Test organisms

Test organisms (species):
other: Gobiocypris rarus
Details on test organisms:
TEST ORGANISM
- Common name: Chinese rare minnow
- Source: Bioassay and Safety Assessment Lab, Shanghai Academy of Public Measurement.
- Length at the end of the study: 2.4 ± 0.2 cm
- Weight at the end of the study: 0.23 ± 0.03 g

ACCLIMATION
- Acclimation period: more than 14 days
- Acclimation conditions: same as test conditions
- Type of food during acclimation: brine shrimp flake
- Feeding frequency during acclimation: daily, until 24 hours before test initiation
- Health during acclimation: no mortality or other health disorders were observed within 7 days before the start of the test.

FEEDING DURING TEST: no

Study design

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

Test conditions

Test temperature:
21.6 - 23.0°C
pH:
7.85 - 8.20
Dissolved oxygen:
68.5 - 94% ASV
Nominal and measured concentrations:
Nominal concentration: 100 mg/L
Mean measured concentration: 6.21 mg/L (geometric mean of measured concentrations in samples taken at the beginning of the test, before and after each renewal period and at the end of the test)
Details on test conditions:
TEST SYSTEM
- Test vessel: 5L glass tanks, fill volume: 4L
- Aeration: continuously over 24 hour periods
- Renewal rate of test solution: every 24 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration: 1
- No. of vessels per control: 1
- Biomass loading rate: 0.6 g fish/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water, dechlorinated by activated carbon and serilized by UV light
- Culture medium different from test medium: not indicated
- Intervals of water quality measurement: measurements of the pH, dissolved oxygen concentration and temperature were made at the beginning of the test, before and after each renewal and at the end of the test.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 12/12 (hours light/hours dark)

EFFECT PARAMETERS MEASURED: mortality at t=0, 3, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable since the test was performed as a limit test.
- Range finding study
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: yes, no mortality and/or abnormalities were observed in the control group and in the treatment group. Based on these results the LC50 was expected to exceed 100 mg/L.
Reference substance (positive control):
yes
Remarks:
potassium dichromate (August 2016)

Results and discussion

Effect concentrations
Key result
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 6.21 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
other: Total organic carbon of the test material
Basis for effect:
mortality
Details on results:
- No abnormalities were observed during the exposure period in any test group.
- No mortality occured in the blank control group or in the treatment group during the exposure period, therefore the LC50 exceeded the highest tested concentration.
- Actual test concentrations were measured to be within ±20% of their geometric mean (6.21 mg/L). And were between 93% and 101% of the initial measured concentration in fresh solutions.
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- LC50: 243 mg/L (95%-CI: 194-297 mg/L)
- Other: result was withing the historical range of this test laboratory (81.6 - 307 mg/L)

Any other information on results incl. tables

Table 1 Contents of TOC in test solutions during the limit test

Duration (h)

Blank control

Treatment group

0

1.38

6.83

24

Old solution

1.07

6.38

New solution

0.944

6.33

48

Old solution

0.922

6.23

New solution

0.883

6.06

72

Old solution

0.718

6.10

New solution

0.628

6.01

96

0.382

5.81

Geometric mean (mg/L)

0.815

5.21

Variation (%)

-

-6.4 ~ 10.0

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
No mortality occured in the control group during the test, dissolved oxygen concentrations were >60% of the air saturation value, measured concentrations remained within 80-120% of initial measured concentrations.
Conclusions:
The 96h-LC50 for fish when exposed to STABiO D-376N exceeded the highest test concentration and was >6.21 mg/L based on the geometric mean measured TOC concentration.
Executive summary:

An acute toxicity test was performed, according to OECD guideline 203 and GLP principles, to assess the toxicity of STABiO D-376N to Gobiocypris rarus (Chinese rare minnow). The test was performed under semi-static conditions with a renewal period of 24 hours. The total test duration was 96 hours. Based on the results of a range finding test in which no mortality was observed at the tested concentration (100 mg/L), a limit test was performed with a nominal concentration of 100 mg/L. Ten fish were exposed to the test solution (one replicate) and ten to a blank control (1 replicate). Observations for mortality were performed at t=0, 3, 24, 48, 72 and 96 hours. To determine the test concentrations during the test period, samples were taken at the beginning of the test, before an after each renewal period and at the end of the test. Analysis was based on total organic content (TOC) and showed that the test concentrations remained within 93 - 101% of the initial measured concentration in the fresh solutions.

No mortality occured during the exposure period in the blank control or in the treatment group. The LC50 of STABiO D-376N was determined to be >6.21 mg/L based on the geometric mean measured TOC concentration.

All acceptability criteria were met and the study was considered valid.