Benzeneacetic acid, 4-(cyclopropylcarbonyl)-.alpha.,.alpha.-dimethyl-, ethyl ester

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:

May 25 to June 11, 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to international guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-(Cyclopropylcarbonyl)-α,α-dimethyl-ethyl ester benzeneacetic acid

EC Number:

605-546-9

Cas Number:

169280-10-8

Molecular formula:

C16 H20 O3

IUPAC Name:

4-(Cyclopropylcarbonyl)-α,α-dimethyl-ethyl ester benzeneacetic acid

Details on test material:

Op. W 0147
Purity: 99.7 %
Expiry date: 01.12.2004
Storage conditions: room temperature

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples were taken at the start and at the end of the main study. The samples were preconditioned with methanol and water. Subsequently the samples were drawn through the cartridge with a flow rate of 1 ml/min, then washed and dried with purified air. Elution was performed with 1.5 ml acetone The acetone was allowed to vaporize and the residue was dissolved in 1 ml acetone with internal standard butylbenzylphthalate.

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Variety: Straus
- Age at study initiation: between 0 and 24h
- Origin: Berlin
- Sex: female
- Medium: M4-medium changing twice a week
- Food type: green algae (Desmodesmus subspicata)
- Photoperiod: 16/8 hour, using neon tubes
- Temperature: 20 +/- 2°C

Animals that did not show any visible damage were selected for the tests.

Study design

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Post exposure observation period:

Not applicable

Test conditions

Test temperature:

20.8 - 21.7

pH:

Main study:
Control (0 mg/l): 7.8 - 8.1
Test concentrations: t=0h pH: 7.9 to 7.0 with increasing concentration; t=48 h pH: 8.2-8.0

Dissolved oxygen:

> 8 mgO2/L at all concentrations throughout the 48-h test period.

Nominal and measured concentrations:

Pre-test: 0, 1, 10 and 100 mg/L
Main test:
nominal: 0, 1.0, 1.6, 2.5, 4.0, 6.3, 10.0, 16.0 mg/L
actual: 0.92, 1.32, 2.25, 3.48, 5.73, 8.53, 14.64 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, 50 ml, tall shape
- No. of organisms per vessel: 5 Daphnia
- No. of vessels per concentration (replicates): 4 vessels, each containing 20 ml test solution
- No. of vessels per control (replicates): 4 vessels, each containing 20 ml dilution water

TEST MEDIUM / WATER PARAMETERS
Dilution water applied in the main study contained
186.32 mg/L of CaCl2.2H2O
71.6 mg/L of MgO4.7H2O
0.08 mg/L of KCl
17.3 mg/L of NaCl
After preparation the dilution water was aerated and pH adjusted to 7.8 ± 0.2.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilities, pH and O2 concentration

TEST CONCENTRATIONS
Test solutions were prepared directly in dilution water and shaken for 24 hours prior to filtration (0.45 µm).
The resulting filtrates were divided over four 50-ml vessels per concentration. Due to the relatively low amounts of substance to weigh in, silica was used at a ratio of 1:100 against dilution water.
- Spacing factor for test concentrations: 10

Reference substance (positive control):

yes

Remarks:

Potassium dichromate CAS n° 7778-50-9

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

8.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

5.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Details on results:

The real concentrations in the test solution were slightly lower than the nominal concentration probably caused by the low water solubility. For the determination of results, the mean of the real concentration of the values at 0 and 48h was used.

Results with reference substance (positive control):

24h-EC50= 1.5mg/L (95%-confidence interval: 1.4 - 1.6 mg/L).
NOEL 24h = 0.625 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Tested according to OECD guideline 202 under GLP (Klimisch code 1): 48h-EC50 is 8.1 mg/L with NOEL of 5.7 mg/L (High quality data).
The available study report is compliant with REACH for satisfying this endpoint and indicates the substance is toxic to aquatic organisms.