(±)-dihydro-3-hydroxy-4,4-dimethylfuran-2(3H)-one

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:

26/03/1999 - 25/11/1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to guideline under GLP, validity criteria met.

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:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(±)-dihydro-3-hydroxy-4,4-dimethylfuran-2(3H)-one

EC Number:

201-210-7

EC Name:

(±)-dihydro-3-hydroxy-4,4-dimethylfuran-2(3H)-one

Cas Number:

79-50-5

Molecular formula:

C6H10O3

IUPAC Name:

(±)-dihydro-3-hydroxy-4,4-dimethylfuran-2(3H)-one

Details on test material:

- Name of test material (as cited in study report): DL- Lactone
- Physical state: White cristalline mass
- Storage condition of test material: At room temperature in the dark

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not relevant

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: During the limit test samples were taken from 100 mg/l and the blank-control for analysis.
- Sampling method: at t= 0 h from freshly prepared and at t= 24 h from thefreshly prepared solutions and the 24h-old solutions. 10 ml from the
approximate centre of the test vessel.
- Sample storage conditions before analysis: Not applicable, samples were analysed on the day of sampling.

Test solutions

Vehicle:

no

Details on test solutions:

DL-LACTONE was completely soluble in test medium at the concentrations tested.
Preparation of test solutions started with stock solutions at 100 mgll. No special treatment other than careful mixing was necessary to dissolve the
test substance in the test medium. The lower test concentrations for the range-finding test were prepared by subsequent dilutions of one of
the stocks in test medium. The test solutions were renewed after 24 hours of exposure. All final test solutions were clear and colourless.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus, 1820
- Age at study initiation (mean and range, SD): <24 h
- Method of breeding: With new-born animals, i.e. less than 3 days old, by placing about 250 of them into 10 litres of M7-medium in an all-glass
culture vessel.
- Feeding during test: no feeding

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Test conditions

Hardness:

250 mg CaC03/l

Test temperature:

20.3 - 20.7 °C

pH:

7.8 - 8.0

Dissolved oxygen:

9.1 - 9.2 (fresh solution)
7.8 - 7.9 (old solution)

Salinity:

Not relevant

Nominal and measured concentrations:

Nominal: 0 and 100 mg/l
Measured (0 h): n.d and 140 mg/l
Measured (24 h old): n.d and 123 mg/l
Measured (24 h fresh): n.d and 138 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open, 100 ml
- Material, size, headspace, fill volume: glass, 80 ml
- Aeration: No aeration of the test solutions
- Renewal rate of test solution (frequency/flow rate): 24 h
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
ISO-medium: the following chemicals (analytical grade) are dissolved in freshly prepared ultra-pure water (tap water
purified by reverse osmosis (milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges:
Milli-Q water; (mg/l): CaCL2.2H20: 293.8, MgS04.7H20: 123.3, NaHC03: 64.8, KCL: 5.8
- Culture medium different from test medium: no
- Intervals of water quality measurement: 24 h

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 hours photoperiod daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilization

Reference substance (positive control):

yes

Remarks:

K2Cr2O7 (Potassium dichromate)

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 130 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: none
The analytical program provided clear evidence that the actual concentrations during the 24-hour period between refreshment had been maintained at more than 80 % of the initial concentration.

Results with reference substance (positive control):

The actual responses in this reference test with K2Cr2O7 are within the ranges of the expected responses at the different concentrations. Hence, the sensitivity of this batch of D. magna was in agreement with the historical data collected at NOTOX.
The 24h-EC50 was estimated to be 1.2 mg/l (regression line: log1O(conc.)=2.76+(probit-2.58)/7.69).
The 48h-EC50 was 0.60 mgll with 95% fiducial limits of 0.52 - 0.76 mg/l.

Reported statistics and error estimates:

The EC50-value was calculated at 48 hours of exposure from the probits of the percentages of affected daphnia and the logarithms of the
corresponding test substance concentrations using the maximum likelihood estimation method (Finney, D.J 1971: Probit analysis, Cambridge University Press, Cambridge, U.K., 3rd edition).

Any other information on results incl. tables

Not relevant

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present test DL-LACTONE induced no acute immobilisation of
Daphnia magna at or below 100 mg/l, corresponding with an average measured concentration
of 130 mg/l (NOEC). Hence, the 48h-ECS0 was above 130 mg/l, the maximum concentration
tested.

Executive summary:

Acute Toxicity Study in Daphnia magna with DL-LACTONE.

The study procedures described in this report were based on the IS0 International Standard 6341 : "Water quality - Determination of the inhibition of the mobility of Daphnia magna Straus -Acute toxicity test, Third edition, 1996-04-01.

DL-LACTONE was completely soluble in test medium at the concentrations tested. The complete project was performed under semi-static test conditions with renewal of test solutions after 24 hours of exposure as DL-LACTONE proved to be unstable in water at pH values of 7 and 9 in the hydrolysis test performed at NOTOX (Project 257568).

A range-finding test was followed by a limit test exposing Daphnia for a maximum of 48 hours to a concentration of 100 mg/l and a blank-control. The test was performed in duplicate with 10 daphnia per vessel. Samples for analysis of actual exposure concentrations were taken from the freshly prepared solutions at the start and the 24-hour old and freshly prepared solutions after 24 hours of exposure. Analysis of the samples taken during the limit test showed that the measured concentration remained within a 20% window during the 24-hour period between refreshment. The average measured concentration corresponded with approximately 130 mg/l.

DL-LACTONE induced no acute immobilisation of Daphnia magna at or below 100 mg/l, corresponding with an average measured concentration of 130 mg/l (NOEC).

Hence, the 48h-EC50 was above 130 mg/l, the maximum concentration tested.