1-dodecyl-1H-imidazole

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

Study period:

4 - 8 Apr 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study, non-GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

laurylimidazole

IUPAC Name:

laurylimidazole

Details on test material:

- Name of test material (as cited in study report): Laurylimidazol
- Physical state: liquid
- Analytical purity: 99%
- Storage condition of test material: at room temperature (ca. 20 °C) in darkness away from direct sunlight

Sampling and analysis

Analytical monitoring:

no

Test solutions

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Laurylimidazole (100 mg/L) was weighed into test water and sonicated 15 minutes, followed by 48 hours of intensive stirring. The solution was then filtered under reduced pressure through a 0.45 µm membrane filter (Schleicher & Schuell NC45).
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): No vehicle
- Evidence of undissolved material (e.g. precipitate, surface film, etc): none, test medium was a clear solution throughout experiment

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: D. magna Straus
- Source: Clone propagated from original, provided 1992 by University of Sheffield.
- Age at study initiation (mean and range, SD): 6-24 hours, not first brood progeny
- Method of breeding: Organisms bred under same light, temperature, and water quality conditions as in the test
- Feeding during test: No

ACCLIMATION
- Acclimation period: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

250 mg/L as CaCO3

Test temperature:

21 °C

pH:

7.7 - 7.8

Dissolved oxygen:

8.0 - 8.5 mg/L

Nominal and measured concentrations:

100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers (100 mL) with glass covers, filled with 50 mL test medium.
- Aeration: none
- No. of organisms per vessel: Ten
- No. of vessels per concentration (replicates): Two
- No. of vessels per control (replicates): Ten
- No. of vessels per vehicle control (replicates): Two
- Biomass loading rate: < 1 Daphnia/ 2mL

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water
294.0 mg/L CaCl2 x 2∙H2O
123.0 mg/L MgSO4 x 7∙H2O
65.0 mg/L NaHCO3
5.8 mg/L KCl
- Alkalinity: 0.8 mmol/l
- Ca/mg ratio: 4:1
- Aeration: Medium was aerated until oxygen saturation was reached prior to study, no further aeration.
- Culture medium different from test medium: Same medium

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 light:dark, with 30 minute transition periods.
- Light intensity: 200-1200 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobiliization 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: no

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

Details on results:

- Behavioural abnormalities: No immobilized test organisms or other signs of intoxication were observed during the test.
- Mobility of control: No immobilized controls.
- Effect concentrations exceeding solubility of substance in test medium: yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48-h EC50 (immobilization) of laurylimidazole to D. magna is > 100 mg/L as water-soluble fraction (OECD 202)

Executive summary:

Toxicity of laurylimidazole 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 chambers. Test substance concentrations were not analytically determined. The 48-hour EC50 of laurylimidazole 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.