Registration Dossier

Diss Factsheets

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

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:
From 2019-01-31 to 2019-07-18
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
yes
Details on sampling:
- Concentrations:see below
- Sampling method: not speified
- Sample storage conditions before analysis: see below. No other indication.

Samples were taken from the test item treated group (5 x 1 mL at the start and 4 x 1 mL at the end of the study) and from the control group (1 x 1 mL at the start and 1 x 1 mL at the end of the study).
Samples were twofold diluted with acetonitrile.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The test solution used in the test was prepared by mechanical dispersion without using of
any solubilizing agent. An amount of 0.0350 g test item was dissolved in 350 mL dilution
water (ISO medium) in order to obtain the concentration of 100 mg/L. The test solution was
freshly prepared in the testing laboratory just before introduction of test animals (start of the
experiment).
Untreated Control: The dilution water (ISO Medium) without test item added was used as untreated control solution.
Reference Control: For the evaluation of the quality of the Daphnia clone and the experimental conditions, Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): not specified
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM :
- Strain/clone: Daphnia magna (Straus)
- Age at study initiation (mean and range, SD): Less than 24 h old at the beginning of the test
- Method of breeding: The Daphnia are bred in the Laboratory of TOXI-COOP ZRT. Test animals were bred under similar (or the same) conditions as that used during the exposure period (holding water, temperature, background colour etc.), therefore additional acclimatisation before the test was not necessary. Brood daphnids were maintained in dilution water at the test temperature for at least 48 hours prior to the start of the test. The Daphnia were fed with concentrated algal suspension of Raphidocelis subcapitata during the holding.
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age of parental stock (mean and range, SD):
- Feeding during test : Test animals were not fed during the exposure.

ACCLIMATION : no, see above
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Hardness:
The reconstituted water (ISO medium) has an approximate theoretical total hardness of 249 mg/L (as CaCO3).
Test temperature:
From 20.8 (0H) to 20.6°C (48H) (control) and from 20.9 (0H) to 20.7°C (48H) (100 mg/L)
pH:
From 7.66 (0H) to 7.95 (48H) (control) and from 7.83 (0H) to 8.04 (48H) (100 mg/L)
Dissolved oxygen:
From 8.47 (0H) to 8.39 mg/L (48H) (control) and from 8.56 (0H) to 8.44 mg/L (48H) (100 mg/L)
Nominal and measured concentrations:
100 mg/L / 82.9 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass beaker; volume approx. 50 mL filled with approx. 40 mL
- Volume of solution: approx. 40 mL
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): NA
- Renewal rate of test solution (frequency/flow rate): no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): NA
- Biomass loading rate: not specified

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (ISO Medium, according to OECD 202) was used as dilution water in the experiment. Separate stock solutions of individual substances were first prepared in deionised water (prepared in TOXI-COOP ZRT. by MILLIPORE ELIX 3 water purification system, Serial Number: F0MA71964D). The ISO Medium was prepared by adding 25 mL from each of four stock solutions to one litre deionised water proportionally.

- Culture medium different from test medium: no
- Intervals of water quality measurement: The water temperature, dissolved oxygen concentration and pH were measured in each test group at the start (before test solutions had been distributed into the test vessels) and in each test vessel at the end of the test. Additionally, the ambient temperature was measured continuously using a min/max thermometer in the climate chamber.

OTHER TEST CONDITIONS
- Adjustment of pH: not specified
- Photoperiod: The light-dark cycle during the test was 16 hours light (artificial illumination) and 8 hours darkness.
- Light intensity: not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The immobility or mortality of the Daphnia was determined by visual observation after 24 and 48 hours of exposure. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker are considered to be immobile. In addition to immobility any abnormal behaviour or appearance is reported.

VEHICLE CONTROL PERFORMED: no , NA

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: Based on the results of the non-GLP Preliminary Range-Finding Test (see above), a single nominal concentration of 100 mg/L (limit test concentration) and a concurrent control were tested in the main study.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (K2Cr2O7)
Key result
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
82.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
> 82.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 82.9 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
No immobilisation or any abnormal behaviour of test animals was observed in the control group and no immobilization or any abnormal behavior of the test animals was observed at the nominal test concentration of 100 mg/L after 48 hours of exposure.
- Effect concentrations exceeding solubility of substance in test medium: no
Results with reference substance (positive control):
The date of the last study (Study Number: 392-202-4466) with reference item Potassium dichromate was: 12 -13 March 2019.
The 24h EC50: 1.58 mg/L (95% conf. limits: 1.34 – 1.85 mg/L)
Reported statistics and error estimates:
A limit test was performed and no toxic effects were observed, therefore statistical analysis was not necessary. The NOEC, LOEC and ECx values of the test item were determined directly from the raw data.
Validity criteria fulfilled:
yes
Remarks:
Immobilisation was not observed in the control group and the dissolved oxygen concentration in control and test vessels was in the range of 8.39- 8.56 mg/L
Conclusions:
No immobilisation or any abnormal behaviour of test animals was observed in the control group and no immobilization or any abnormal behavior of the test animals was observed at the nominal test concentration of 100 mg/L after 48 hours of exposure. The 48-h NOEC was determined to be 82.9 mg/L (measured) and the 48-h LOEC and the EC50 values were determined to be > 82.9 mg/L (measured).
Executive summary:

The purpose of this study was to evaluate the influence of the test item 2,5-Dimethoxytetrahydrofuran on the mobility respectively survival of Daphnia magna, according to OECD 202 guideline and C2 EU method, and following GLP. Young Daphnia were exposed to the test item in aqueous test media for 48 hours under defined conditions, in a static-test. The percentage of Daphnia no longer capable of swimming at the end of the test or being dead was recorded. Based on the results of the preliminary test (static test), the test item had no toxic effect on the daphnids up to a concentration of 100 mg/L (limit concentration). Therefore, the main test was performed at a concentration level of 100 mg/L (nominal) and a concurrent control.

The analytically measured test item concentration did not remain within ± 20 % of the nominal during the test period of 48 hours; therefore, biological results are based on the geometric mean of the measured concentrations.

No immobilisation or any abnormal behaviour of test animals was observed in the control group and no immobilization or any abnormal behavior of the test animals was observed at the nominal test concentration of 100 mg/L after 48 hours of exposure. The 48-h NOEC was determined to be 82.9 mg/L (measured) and the 48-h LOEC and the EC50 values were determined to be > 82.9 mg/L (measured).

All validity criteria were met and therefore the study can be considered as valid.

Description of key information

No immobilisation or any abnormal behaviour of test animals was observed in the control group and no immobilization or any abnormal behavior of the test animals was observed at the nominal test concentration of 100 mg/L after 48 hours of exposure. The 48-h NOEC was determined to be 82.9 mg/L (measured) and the 48-h LOEC and the EC50 values were determined to be > 82.9 mg/L (measured).

Key value for chemical safety assessment

Additional information

The purpose of this study was to evaluate the influence of the test item 2,5-Dimethoxytetrahydrofuran on the mobility respectively survival of Daphnia magna, according to OECD 202 guideline and C2 EU method, and following GLP. Young Daphnia were exposed to the test item in aqueous test media for 48 hours under defined conditions, in a static-test. The percentage of Daphnia no longer capable of swimming at the end of the test or being dead was recorded. Based on the results of the preliminary test (static test), the test item had no toxic effect on the daphnids up to a concentration of 100 mg/L (limit concentration). Therefore, the main test was performed at a concentration level of 100 mg/L (nominal) and a concurrent control.

The analytically measured test item concentration did not remain within ± 20 % of the nominal during the test period of 48 hours; therefore, biological results are based on the geometric mean of the measured concentrations.

No immobilisation or any abnormal behaviour of test animals was observed in the control group and no immobilization or any abnormal behavior of the test animals was observed at the nominal test concentration of 100 mg/L after 48 hours of exposure. The 48-h NOEC was determined to be 82.9 mg/L (measured) and the 48-h LOEC and the EC50 values were determined to be > 82.9 mg/L (measured).

All validity criteria were met and therefore the study can be considered as valid.