Benzeneacetic acid, .alpha.,.alpha.-dimethyl-, ethyl ester

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start of study: September 01 - September 05, 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 1a: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Remarks:

Principles of Good Laboratory Practice, annex of paragraph 19a, section 1 of the chemical law

Test material

Test material information

Constituent 1

Reference substance name:

α,α-Dimethyl-ethyl ester benzeneacetic acid

EC Number:

608-307-7

Cas Number:

2901-13-5

Molecular formula:

C12 H16 O2

IUPAC Name:

α,α-Dimethyl-ethyl ester benzeneacetic acid

Details on test material:

Name: Dimethylphenylessigsäureethylester
Synonyms: EDMPA
Chemical name: Benzeneacetic acid, α,α-dimethyl-, ethyl ester
Certificate of analysis: March 18, 1997
Purity: 99.8%
Appearance: clear, colorless liquid
Solubility: 0.3 g/L in water
Batch number: B 0006
Date of production: March 12, 1997
Date of expiry: March, 2000
Storage conditions: darkness at approximately 20°C in a fume cupboard

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples (20 mL) were diluted with mobile phase (acetonitrile) before measurement.

Test solutions

Details on test solutions:

Test solutions were prepared using an Ultra-Turrax and quantitatively transferred to 4-litre test vessels and were stirred for 24h.

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Date of hatching: May 15, 1997
Delivery date: June 9, 1997
Fish were kept in dilution water 14 days before the start of the exposure.
Temperature: 22+/- 1°C
Oxygen content: >= 80 % of the saturation value
Light period: 12h daily
Population density: <= 1g fish/L water
Feeding: twice daily ad libitum
Food: Tetra Min, Tetra Werke, Melle (Germany)
Body length varied from 2.5 to 2.7 cm (mean 2.6).

Study design

Test type:

semi-static

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Not applicable.

Test conditions

Hardness:

2.3 mmol Ca2+ + Mg2+/L during the study.

Test temperature:

Controls (0 mg/L): 21.4 - 22.1 ºC
Test concentrations: 21.4 - 22.2 ºC

pH:

Controls (0 mg/L): 7.6- 8.3
Test concentrations: 7.4 - 8.3

Dissolved oxygen:

Controls (0 mg/L): 7.6 - 9.6 mg O2/L
Test concentrations: 7.6 - 9.6 mg O2/L

Nominal and measured concentrations:

Nominal test concentrations: 0-10-22-50-100 mg/L
Mean measured concentrations: 0-6.3-12.4-30.8-62.5 mg/L

Details on test conditions:

TEST SYSTEM
- Test chambers were calibrated to 4L (length 20 cm, width 15 cm, height 20 cm) and were not aerated during the course of the study.
- Chambers illumintated for 12h
- Light intensity: 700 lux
Allocation of fish: 7 fish in 6 chambers
TEST MEDIUM / WATER PARAMETERS
Reconstituted water, composition according to ISO/DIS 7346/1 was used as water for dilution. The dilution was aerated until oxygen saturation.
The pH was measured before the use of each batch. It was in the range of 8.0-8.3.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

12.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

6.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 3

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

19.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 4

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

12.4 - 30.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 5

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

30.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

ln the 62.5mg/L group recording of symptoms was not possible because of 100% lethality at the first inspection date.
Symptoms and lethality were observed at 12.4 and 30.8 mg/L. The 6.3 mg/L group exhibited symptoms but no lethality.
The fish showed changes in appearance, behavior, swimming behavior and respiration rate in all tested concentration groups. Symptoms occurred during the entire exposure time.
Dead fish showed dark or light colored integument. Some fish were curved.

Any other information on results incl. tables

Sublethal observations / clinical signs:

No data

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this test the LC50 of the substance after 96 hours was between 12.4 and 30.8 mg/L (based on the mean of analytically determined concentrations).