Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conducted under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

EC Number:

246-771-9

EC Name:

Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

Cas Number:

25265-77-4

Molecular formula:

C12H24O3

IUPAC Name:

3-hydroxy-2,2,4-trimethylpentyl 2-methylpropanoate

Constituent 2

Reference substance name:

3-hydroxy-2,2,4-trimethylpentyl isobutyrate

EC Number:

201-049-2

EC Name:

3-hydroxy-2,2,4-trimethylpentyl isobutyrate

Cas Number:

77-68-9

Molecular formula:

C12H24O3

IUPAC Name:

3-hydoxy-2,2,4-trimethylpentyl isobutyrate

Details on test material:

CC(C)C(=O)OCC(C)(C)C(O)C(C)C
CC(C)C(=O)OC(C(C)(C))C(C)(C)CO

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 1.6,38.4,68.8, 123.2,222.4, and 400.0 mg/L nominal
- Sampling method: Aliquots ofthe exposure solutions were submitted for concentration determinations at times 0 and 48 hours with the
exceptions of replicates A and B containing nominally 400.0 mg/L. Replicates A and B containing nominally 400.0 mg/L were submitted at time 0
only due to 100% immobility observed amongst the organisms within the test vessels at the 6-hour observation period.

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Adult Daphnia magna were reared within 100-L stainless steel culturing tanks located within the Eco-Chem Testing Group, Building 320, Kodak Park, Rochester, New York. The gravid daphnids used to produce the test animals for the study were obtained from rearing tanks which had been established for at least two weeks. Prior to the study, approximately 100 gravid daphnids were transferred by net into two 20-cm diameter bowls containing 1 liter of diluent water and 5 mL of food. After 18 hours in these bowls, all adult daphnids were removed by using nets and pipets. After an additional 6-hour period, the neonates within the bowls were between 6 and 24 hours old and were used for the study.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

120 mg/L

Test temperature:

20 + or - 1C

pH:

7.4 - 8.2

Dissolved oxygen:

8.0 - 9.0 mg/L

Nominal and measured concentrations:

See Table 1

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 250 mL glass beakers
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
The water used in the test was pumped from Lake Ontario by the Kodak Park Lake Station Water Treatment Facility into a large underground storage reservoir located near the Environmental Sciences Section testing facility (Building 320, Kodak Park). This water subsequently was pumped into the laboratory where it passed through 3-micron (pore size) polypropylene filter tubes, next through a series of powdered, activated carbon filter tubes, and finally through another set of 3-micron polypropylene filter tubes. The filtered water stream next received 150 ppb ofNa2S203 via a chemical injection system. This treatment further reduced trace levels of residual chlorine. The filtered-treated water was subsequently tempered to 20 ± 2°C by passage through a heat-exchange unit. The filteredtreated-tempered water supply was distributed throughout the testing facility through PVC and stainless steel piping. Upon reaching the laboratory, the filtered-treated-tempered water cascaded through a column degassing unit into an open, aeration basin for seasoning prior to use. The test diluent water was drawn from this source at 20 ± 2°C. Representative values for the hardness and total alkalinity (both as CaC03) for the study period were 120 mg/L and 95 mg/L, respectively.

OTHER TEST CONDITIONS
- Photoperiod: The light/dark cycle ofthe lighting regime during the test was 16 hours on and 8 hours off, with a 20-minute transition period.



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Observations for signs of immobility and stress were made at times 0,6,24, and 48 hours.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

147.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL =83.8 - 211.7 mg/L

Reported statistics and error estimates:

The data were analyzed using descriptive statistics, plots and model fitting. Each replicate set was examined separately, and then the replicates were pooled for further analyses. The model fitting included determination ofthe best fitting curve to the data, using F tests, examination of residuals and the r squared statistic. Statistical significance and goodness of fit were detected using an alpha level of 0.05. The appropriate endpoints were calculated from the best fitting model and 95% confidence intervals were determined for each point estimate. The confidence intervals were calculated using the appropriate t or Z statistics, the root mean square error term from the equation, and the sample size of the y observations.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

The acute toxicity of TEXANOL Ester-Alcohol to Daphnia magna was determined in a 48-hour, static, aquatic effects test. The exposure solutions for the test were prepared by direct addition of appropriate amounts of a test article stock solution to 500-mL volumetric flasks. Aliquots of each solution were transferred to the daphnid test vessels and served as exposure solutions for this test. Exposure concentrations used throughout this report, and in all endpoint calculations, were based on the analyzed mean values of the test article exposure solutions at times 0 and 48 hours as determined by gas chromatography (GC). The exposure solutions in replicate series A contained the test article at concentrations of 4.1, 36.8, 63.3, 114.0, 207.0, and 378.0 mg/L. The exposure solutions in replicate series B contained the test article at concentrations of 4.1, 37.6, 62.6, 116.0, 209.0, and 379.0 mg/L. Replicate series daphnid immobility results were pooled for statistical analyses. The 24-hour EC50 value for Daphnia magna was determined to be 164.7 mg/L for the pooled replicates. The 48-hour EC50 value for Daphnia magna was determined to be 147.8 mg/L for the pooled replicates.