Titanium zirconium oxide

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:

January 23, 2018 - January 26, 2018

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)

Version / remarks:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Remarks:

The test item concentration in the reconstituted water was not quantified at the start and the end of this study. Because of its insolubility in water, the compound cannot be detected with standard analytical methods.

Vehicle:

yes

Remarks:

Reconstituted water (ELENDT M4 medium)

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- A stock preparation with a test item concentration of 100 mg/L was freshly prepared. For that purpose, the test item was weighed in a calibrated flask and vehicle was added. The preparation was stirred with a magnetic stirrer for 24 hours. Then the formulation was passed through a fitter membrane (pore size: 0.2 μm). The filtrate was used for the study. The pH was not adjusted.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Daphnia magna Straus
- Source: IBACON GmbH (Roßdorf, Germany)
- Age of parental stock (mean and range, SD): until about 6 weeks old
- Feeding during test: no

ACCLIMATION
- Acclimation conditions: same as test
- Type and amount of food: ad libitum with unicellular green algae Pseudokirchneriella subcapitata
- Feeding frequency: three times per week
- Health during acclimation (any mortality observed):

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Offspring are removed from the vessels at least twice per week. At the start of the experimental phase the daphnids were cautiously removed using a pipette, separated from the reconstituted water using a fine-mesh sieve, and transferred into the test vessels containing test media (test item group) or reconstituted water (control group).

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

236 mg CaCO3/L

Test temperature:

20.7 to 21.1°C

pH:

7.71 - 7.80

Dissolved oxygen:

8.16 - 8.61 mg O2/L

Salinity:

NA

Conductivity:

744 µS/cm

Nominal and measured concentrations:

100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass vessels
- Type: open
- Material, size, fill volume: glass, 20 mL, 20 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (ELENDT M4 medium) according to OECD Guideline

- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light/ 8 hours darkness
- Light intensity: 589 Lux and 583 Lux prior to and at the end of the exposure period, respectively

EFFECT PARAMETERS MEASURED:


VEHICLE CONTROL PERFORMED: yes/no

RANGE-FINDING STUDY
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: No immobilization was observed at a concentration of 100 mg/L under open static conditions.

Reference substance (positive control):

no

Remarks:

No positive control used in this study. The accuracy and reliability of the test method is demonstrated periodically as recommended by guidelines with potassium dichromate.

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Other adverse effects control: no
- Any observations that might cause a difference between measured and nominal values: no:

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: Immobilization
- Limit test: no
- Dose-response test: Yes
- ECx: 48-h EC50 = 0.86 mg/L

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study, an aqueous solution of nominal 100 mg/L of the test item revealed no toxicity to daphnids. The 48h EC50 was > 100 mg/L (nominal) and, thus, could not be deterrnined in this study.

Executive summary:

The objective of this study was to determine the effect of the test item on the immobilization of Daphnia magna according to OECD Guideline 201.

Juvenile daphnids were exposed to a nominal test item concentration of 100 mg/L (limit test) in an open static system. 20 daphnids, divided into four replicates, each with five animals were used in the test item group and the control group. The daphnids were observed for immobilization after 24 and 48 hours of exposure.

The test item concentration in the reconstituted water was not quantified at the start and the end of this study. Because of its insolubility in water, the compound cannot be detected with standard analytical methods and the development of an analytical method with a sufficiently low detection and quantification limit is complex. Due to the absence of any adverse effects at the saturation concentration, the study was perforrned without analytical concentration verification.

No effect on the mobility of the daphnia was observed at a nominal concentration of 100 mg/L.

Under the conditions of the present study, an aqueous solution of nominal 100 mg/L of the test item revealed no toxicity to daphnids. The 48h EC50 was > 100 mg/L (nominal) and, thus, could not be deterrnined in this study.

Description of key information

Under the conditions of the present study, an aqueous solution of nominal 100 mg/L of the test item revealed no toxicity to daphnids. The 48h EC50 was > 100 mg/L (nominal) and, thus, could not be deterrnined in this study.