Isobutyl isobutyrate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994 to 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

The exposure solutions for the test were prepared by direct addition of appropriate amounts of the test material to 500 mL volumetric flasks. Aliquots of each solution were transferred to the daphnid test vessels and served as exposure solutions. The test material solutions and diluent water controls were renewed each 24 hours. At each renewal period, the daphnids were transferred from the 24 hour old solutions to the renewed solutions. Samples of the renewal solutions and old solutions were sent for chemical analysis.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna were reared in-house and neonates betwee 6 and 24 hours old were used for testing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

120 mg/L

Test temperature:

20 +/- 1 degree Celcius

pH:

6.9 to 9.2

Dissolved oxygen:

8.4 to 9.2

Nominal and measured concentrations:

Replicate A measured concentrations 53.72, 82.80, 109.10, 285.20 and 178. 15 mg/L and Replicate B measured concentrations 55.82, 70.30, 131.35, 227.08 and 32.85 mg/L. Nominal concetrations of 95.2, 171.5, 308.6, 555.5, and 1000 mg/L.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

59.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Replicate A

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

55.8 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

replicate B

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

53.7 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

replicate A

Details on results:

An NOEC value at 48 hours was not determinable for replicate B

Reported statistics and error estimates:

A computer program developed by C.E. Stephan and ASTM was used to compute point and interval estimaes of the EC50 values for this test. NOEC values were defined as the lowest analytzed concentration of the test material which resulted in effects which were not significantly different from those of the control group. Statistical signifiance was detected using an alpha level of 0.05.

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of the test material as measured by the 24, and 48-hr EC50 values, did not vary considerably over the course of the study. The 48-hr EC50 values for Daphnia magna for replicate series A and B were determined to be 59.3 mg/L and 55.8 mg/L, respectively.

Executive summary:

An acute toxicity test with the aquatic invertebrate, Daphnia magna, was conducted following OECD 202 with expsoure to Isobutyl Isobutyrate. The 48 -hr EC50 values were reported for each of the two replicates as 59.5 and 55.8 mg/L, respectively. The geometric mean 48 -hr EC50 value is calculated as 57.5 mg/L.

Description of key information

An acute toxicity test with the aquatic invertebrate,Daphnia magna, was conducted following OECD 202 with expsoure to Isobutyl Isobutyrate. The 48 -hr EC50 values were reported for each of the two replicates as 59.5 and 55.8 mg/L, respectively. The geometric mean 48 -hr EC50 value is calculated as 57.5 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

57.7 mg/L