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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study, non-GLP, no measurement of test substance concentration

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
Laurylmercaptobutyronitrile
IUPAC Name:
Laurylmercaptobutyronitrile
Details on test material:
- Name of test material (as cited in study report): Laurylmercaptobutyronitril.
- Substance type: Mono-constituent
- Physical state: Liquid
- Analytical purity: 99%
- Storage condition of test material: Room temperature at about 20 °C, in the dark away from direct sunlight

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
- Method: A supersaturated dispersion of the test substance at a nominal loading rate of 100 mg/L was prepared by weighing 49 mg of substance in to 500 mL medium. The dispersion was ultrasonicated for 15 minutes followed by 48 hours of intense stirring at room temperature in the dark. The supersaturated dispersion was then filtered under reduced pressure through a 0.45 µm membrane. The filtrate was used directly.

- Evidence of undissolved material (e.g. precipitate, surface film, etc): Solution remained clear and colorless throughout test.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Strain: Strauss
- Source: Internal stock, strain originally supplied by University of Sheffield/UK
- Age at study initiation: 6-24 hours, not first brood progeny
- Feeding during test: no

ACCLIMATION
- Acclimation period: Organisms raised in same conditions as test, no acclimation period

Study design

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

Test conditions

Hardness:
250 mg CaCO3/L
Test temperature:
20 - 21 °C
pH:
7.7 - 7.9
Dissolved oxygen:
8.3 - 8.5 mg/L
Nominal and measured concentrations:
Nominal loading rate: 100 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 100 mL glass beakers filled with 50 mL test medium
- Type: Open
- Aeration: no. Test medium aerated to oxygen saturation prior to test.
- No. of organisms per vessel: Ten
- No. of vessels per concentration (replicates): Two
- No. of vessels per control (replicates): Two

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted test water. Purified water containing the following analytical grade salts:
CaCl2∙2H2O: 294 mg/L
MgSO4∙7H2O: 123 mg/L
NaHCO3: 65 mg/L
KCl: 5.8 mg/L

- Alkalinity:0.8 mM
- Ca/mg ratio: 4:1
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Photoperiod: 16h light: 8h darkness, 30 minute transition periods
- Light intensity: 200 - 1200 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immoblization and other signs of intoxication at 24 and 48 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: None
- Justification for using less concentrations than requested by guideline: Limit test
- Range finding study: Yes. No toxicity found at any dose tested
- Results used to determine the conditions for the definitive study: Yes, limit test based on lack of toxicity.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate tested annually

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: Water soluble fraction
Basis for effect:
mobility
Remarks on result:
other: No immobilization or other toxic effects observed.
Details on results:
- Behavioural abnormalities: none
- Other biological observations: none
- Mortality of control: none
- Other adverse effects control: none
- Effect concentrations exceeding solubility of substance in test medium: yes
- other: No immobilization or other mortality observed in control or exposed organisms after 48 hours.
Results with reference substance (positive control):
Results not available

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 48-hr EC50 of laurylmercaptobutyronitrile to Daphnia magna was >100 mg/L (nominal loading rate). No toxicity was observed from a water soluble fraction prepared at 100 mg/L
Executive summary:

Toxicity of laurylmercaptobutyronitrile to D. magna was assessed in a limit test conducted according to OECD 202. The test substance was not fully soluble at the limit of 100 mg/L, so a water-soluble fraction was made. Test substance (100 mg/L) was sonicated in reconstituted test water for 15 minutes, stirred for 48 hours, and filtered to 0.45 µm under reduced pressure. No immobilization or sublethal effects were observed in controls or test solutions. Test substance concentrations were not analytically determined. The 48-hour EC50 of laurylmercaptobutyronitrile is >100 mg/L.

The test was conducted according to an internationally accepted guideline but was not GLP compliant. Test substance concentrations were not analytically confirmed. This test is considered reliable with restrictions. It is suitable for Risk Assessment, Classification & Labeling, and PBT Analysis.

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