α-hydroxy-β,β-dimethyl-γ-butyrolactone

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:

12.10. - 15.10.2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to guideline, under GLP

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

α-hydroxy-β,β-dimethyl-γ-butyrolactone

EC Number:

209-963-3

EC Name:

α-hydroxy-β,β-dimethyl-γ-butyrolactone

Cas Number:

599-04-2

Molecular formula:

C6H10O3

IUPAC Name:

(3R)-3-hydroxy-4,4-dimethyloxolan-2-one

Constituent 2

Reference substance name:

209 963 3

IUPAC Name:

209 963 3

Details on test material:

- Name of test material (as cited in study report): R-Pantolactone
- Physical state: solid
- Storage condition of test material: RT (20°)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
- Water solubility (under test conditions): well soluble

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: For the determination of the actual test item concentration, duplicate samples were taken from the single test concentration at the start and at the end of the test medium renewal periods. For the aged test medium samples, the contents of the respective replicates were combined.
At all sampling dates, the concentration of the test item R-Pantolactone was analytically measured in the duplicate test medium samples and in the control. All samples were analyzed immediately after sampling.

Test solutions

Vehicle:

no

Details on test solutions:

The test medium was prepared by dissolving 101.4 mg (at test start) and 102.9 mg of test item (at test item renewal) completely in 1000 mL of test water, under intense stirring for 5 minutes at room temperature. The test medium was prepared just before the introduction of the daphnids at test start and prior to the test medium renewal.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus
- Source: University of Sheffield
- Age at study initiation (mean and range, SD): 6-24 h
- Method of breeding: in reconstituted water of the quality identical to the water quality used in the tests (in respect to pH, main ions, and total hardness) and under temperature and light conditions identical to those of the tests
- Feeding during test: no

ACCLIMATION
- Acclimation conditions (same as test or not): yes
- Type and amount of food: daphnids are generally fed three times a week with an algal suspension of the green algae Scenedesmus subspicatus CHODAT, Strain No. 86.81 SAG and cultivated at Harlan Laboratories under standardized conditions or a mixture of this algal suspension and a commercial fish diet.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

not applicable

Test conditions

Hardness:

250 mg/L as CaCO3

Test temperature:

20 - 21 °C

pH:

7.8 - 8.0

Dissolved oxygen:

8.5 - 8.7

Salinity:

-

Nominal and measured concentrations:

Nominal concentration is 100 mg/L; the average recoveries found in the treatment samples were 102% (day 0/0 h), 95% (day 1/24 h), 101% (day 1/0 h) and 103% (day 2/24 h) of the nominal concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers filled with 50 mL of test medium. The test vessels were covered with glass plates to reduce the loss of water by evaporation and to avoid the entry of dust into the solutions.
- Renewal rate of test solution (frequency/flow rate): 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


OTHER TEST CONDITIONS
- Photoperiod: 16/8
- Light intensity: 520-680 lux

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

In the control and at the test item concentration of 100 mg/L, no immobilized test organisms were observed during the test period of 48 hours.

Results with reference substance (positive control):

48-hour EC50: 0.71 mg/L indicating that the sensitivity of the test organisms was within the internal historical range (48-hour EC50 from 1996 to 2009: 0.53 - 1.1 mg/L).

Reported statistics and error estimates:

Not applicable

Any other information on results incl. tables

The analytically determined concentration of the test item in the test medium at the start and at the end of the test medium renewal periods ranged between 95 and 103% of the nominal value. Under the conditions of the test, the test item concentration was constant during the test period of 48 hours. Therefore, all reported results are related to the nominal concentration of the test item. Furthermore, the analytical results show the correct dosage of the test item at the start of each test medium renewal period.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In the control and at the test concentration of 100 mg/L, no immobilized test organisms were observed during the test period of 48 hours.

Executive summary:

A semi-static limit test was performed in accordance with the test guidelines to demonstrate that the test item has no toxic effect on Daphnia magnaat a nominal concentration of 100 mg/L.

 

In the control and at the test concentration of 100 mg/L, no immobilized test organisms were observed during the test period of 48 hours.

 

Therefore, the 48-hour NOEC and the 48-hour EC₀of R-Pantolactone toDaphnia magnawere determined to be at least 100 mg/L. The 48-hour NOEC and the 48-hour EC₀might even be higher, but concentrations above 100 mg/L were not tested, in accordance with the test guidelines. The 48-hour EC₅₀and the 48-hour EC₁₀₀were clearly higher than 100 mg/L. These values could not be quantified due to the absence of toxicity of R-Pantolactone at the test concentration of 100 mg/L.