Registration Dossier

Administrative data

Endpoint:
toxicity to other aquatic vertebrates
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Acute toxicity of substituted phenols to Rana japonica tadpoles and mechanism-based quantitative structure-activity relationship (QSAR) study
Author:
Wang X., Dong Y., Wang L. & Han S.
Year:
2001
Bibliographic source:
Chemosphere, 44 (3), 447-455

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Acute toxicity of Methyl salicylate to R. japonica tadpoles was determined post 12 -h and 24 -h semi-static exposure. Thus, a six-step concentration series in geometric grade ranging from no effect to 100% lethal concentration were set after range finding experiments. Ten tadpoles were employed for each test and placed in a 1000 ml pyrex beaker containing 500 ml test solution or aerated chloride-free water (control). All experiments were performed with three replicates of each treatment group and unexposed controls. Mortality was recorded and 12-h and 24-h LC50, based on nominal concentrations, was calculated.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 2-Hydroxyl, methyl benzoate
- Supplier: Methyl salicylate was provided by Department of Chemistry at Nanjing University.
- Analytical purity: This substance was of sufficient purity (analytical purity) and further purification was not necessary.

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
no data

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION:
- Method: Aerated chloride-free water was used for preparing the stock solutions of chemicals and test dilution.
- Controls: The aerated chloride-free water without test compounds served as the control.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): no data
- Concentration of vehicle in test medium (stock solution and final test solution): no data

Test organisms

Test organisms (species):
other: Rana japonica
Details on test organisms:
TEST ORGANISM
- Common name: frog (tadpole)
- Strain: Rana japonica
- Source: Naturally fertilized egg masses of R. japonica were collected from a permanent pond in Nanjing, where R. japonica were exclusively bred.
- Age/weight/length at study initiation: Thirty-day-old (stage 30 to stage 32, Gosner (1960)) healthy individuals of similar size and weight were employed for the test. The average body length and body weight were 2.5 ± 0.1 cm and 0.09 ± 0.01 g, respectively.
- Method of breeding: Eggs and the resulting tadpoles were cultured in aerated stream water (Cl- 3.40 mg/l, pH 7.74, dissolved oxygen concentration 9.6 mg/l, Na+ 2.35 mg/l, Ca2+ 48 mg/l) in the laboratory at room temperature (22-25°C). Tadpoles were fed an excess of rinsed, salt free canned spinach daily and water was renewed every other day. Feeding was halted 24h prior to testing.

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
24 h
Post exposure observation period:
no data

Test conditions

Hardness:
no data
Test temperature:
All exposures took place at water temperature 22-25°C.
pH:
The pH of test solution, measured by a PHS-3C pH-Meter, was 6.55.
Dissolved oxygen:
no data
Salinity:
no data
Nominal and measured concentrations:
no data
Details on test conditions:
TEST SYSTEM
- Test vessel: 1000 ml pyrex beakers containing 500 ml test solution or aerated chloride-free water.
- No. of organisms per vessel: Ten tadpoles were employed for each test.
- No. of vessels per concentration (replicates): All experiments were performed with three replicates of each treatment group.
- No. of vessels per control (replicates): All experiments were performed with three replicates.
- No. of vessels per vehicle control (replicates): no data
- Renewal rate of test solution (frequency/flow rate): Solutions and the control were renewed every 6 h to achieve semi-static exposure.

OTHER TEST CONDITIONS
- Adjustment of pH: The pH of test solution, measured by a PHS-3C pH-Meter, was 6.55.
- Photoperiod: 14:10 (L:D)
- Temperature: All exposures took place at water temperature 22-25°C in a controlled environmental chamber.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
Mortality was recorded and LC50 based on nominal concentrations was calculated.

TEST CONCENTRATIONS
- Range finding study: no data
- Test concentrations: A six-step concentration series in geometric grade ranging from no effect to 100% lethal concentration were set after range finding experiments.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
12 h
Dose descriptor:
LC50
Effect conc.:
3.315 mmol/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
24 h
Dose descriptor:
LC50
Effect conc.:
3.303 mmol/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Details on results:
- Mortality of control: The test was terminated on condition that mortality in controls exceeded 10%.
- 12-h and 24-h LC50 were respectively 3.315 and 3.303 mmol/L, ie 504.38 and 502.55 mg/L.
Results with reference substance (positive control):
no data
Reported statistics and error estimates:
Logarithms of inverse of median lethal concentrations after 12-h and 24-h exposure, expressed as 12 h-LC50 (mmol/l) and 24 h-LC50 (mmol/l), were calculated for each compound as toxicity using nonlinear regression in STATISTICA for Windows software (1995).

Applicant's summary and conclusion

Conclusions:
Acute toxicity of Methyl salicylate to R. japonica tadpoles was determined post 12 -h and 24 -h semi-static exposure. 12 -h and 24 -h LC50 were respectively 3.315 and 3.303 mmol/l, ie 504.38 and 502.55 mg/l.