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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
28.03.2011 to 31.03.2011
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
The M4 medium (control) and the test substance preparation (100 mg/L M4 medium) were filtered through membrane filter. 10 mL (5 mL for TIC analysis) filtrate of the test substance preparation and the control were filled into the measuring vessel and firmly closed with aluminium foil. Then, they were placed in the sampling unit and measured automatically as triplicate determination with the TC and TIC analyser.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was found to be poorly water soluble. Therefore, 100 mg test substance were added to 1000 mL M4 medium and stirred for 24 h. The test substance preparation was then filtered through a filter paper. The control (M4 medium) was treated in the same way.
- Controls: M4 medium served as control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): no vehicle used
- Evidence of undissolved material (e.g. precipitate, surface film, etc): After filtration, the test substance preparation was present as a clear solution

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea (Daphnia magna)
- Strain: Straus
- Source: the organisms were held in the testing laboratory and descended from a population received from 'Landesumweltamt (NRW)', Düsseldorf (Germany) on 30.05.2006
- Age at study initiation (mean and range, SD): <24 h
- Method of breeding: The daphnids were held in 2 L beakers filled with ca. 1400 mL M4 medium. 15-20 adult organisms were held in one beaker. The breeding beakers were kept at an artificial light-dark cycle of 16 to 8 h. The breeding beakers were placed in a temperature controlled laboratory at 20 +/- 2°C. The breeding medium was renewed three times a week (Monday, Wednesday, and Friday).
- Feeding during test: no

ACCLIMATION
- Acclimation period: not necessary
- Acclimation conditions (same as test or not): holding/breeding conditions the same as in the test
- Type and amount of food: during holding/breeding the daphnids were fed with Desmodesmus subspicatus from Monday to Friday
- Feeding frequency: daily
- Health during acclimation (any mortality observed): yes

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Test temperature:
at test start: 21.3°C (control), 21.3°C (test substance solution)
after 24 h: 21.1°C (control), 21.1°C (test substance solution)
at test termination: 21.1°C (control), 21.1°C (test substance solution)
pH:
at test start: 8.09 (control), 7.79 (test substance solution)
after 24 h: 8.20 (control), 7.75 (test substance solution)
at test termination: 8.33 (control), 8.01 (test substance solution)
Dissolved oxygen:
at test start: 6.18 mg/L (control), 5.88 mg/L (test substance solution)
after 24 h: 5.93 mg/L (control), 5.98 mg/L (test substance solution)
at test termination: 6.09 mg/L (control), 6.04 mg/L (test substance solution)
Nominal and measured concentrations:
100 mg/L nominal
Details on test conditions:
TEST SYSTEM
- Test vessel: beaker
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass/50 mL/-/30 mL
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): test conducted under static conditions
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 5 (one additional beaker was used for measurement of temperature, oxygen saturation, and pH value)
- No. of vessels per control (replicates): 5 (one additional beaker was used for measurement of temperature, oxygen saturation, and pH value)
- No. of vessels per vehicle control (replicates): no vehicle used

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium
- Culture medium different from test medium: no
- Intervals of water quality measurement: temperature, oxygen saturation, and pH value were measured daily

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light/8 h dark
- Light intensity: 700 +/- 50 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation (daily)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: only one concentration tested (100 mg/L)
- Justification for using less concentrations than requested by guideline: limit test
- Range finding study: not reported
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
dissolved
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
dissolved
Basis for effect:
mobility
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Mortality:
- EC50/LC50: 24 h EC50=1.0 mg/L (range given in the guideline: 0.6-2.1 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test substance preparation of nominal 100 mg/L induced no immobilisation to the exposed Daphnia within 48 h of exposure (48 h NOEC >=100 mg/L; 48 h EC50>100 mg/L).
Executive summary:

The toxicity of the analogue substance hexanoic acid, 3,5,5-trimethyl-, tin (2+)salt (2:1) was investigated in a study conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) and EU Method C.2 (Acute Toxicity for Daphnia). In this limit test, daphnids were exposed to a nominal test substance concentration of 100 mg/L over a period of 48 h under static conditions. As the test substance was poorly water soluble a water accommodated fraction was prepared (dissolving of test substance in M4 medium, stirring for 24 h, filtration). DOC analysis showed that no loss of substance occurred during the exposure period. At the concentration tested no immobilisation of daphnids was observed (48 h NOEC>=100 mg/L; 48 h EC50>100 mg/L).

The study is regared as reliable with restrictions (only one concentration was tested) and satiesfies the requirements of the guideline.

Synopsis

Test organism/age: Daphnia magna Straus/<24 h

Test type: static

48 h NOEC: >=100 mg/L

48 h EC50>100 mg/L (values refer to nominal concentrations)

Endpoint(s) affected: mobility