Zirconium dioxide

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:

from 08 AUG 1994 to 18 OCT 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the EU method C2 and the GLP. But no analytics were performed.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

not specified

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Zirconium dioxide

EC Number:

215-227-2

EC Name:

Zirconium dioxide

Cas Number:

1314-23-4

Molecular formula:

O2Zr

IUPAC Name:

zirconium dioxide

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solutions were prepared by dissolving 100 mg of substance in 1000 g of test medium. The flasks were magnetically stirred for 24h at 30°C, then for 24h at 20°C and finally centrifugated at circa 9000 g for 20 min. The extracted solution was then used as test solution. The concentration of this test solution was expressed in percentage of dilution of the extracted solution. Here, only the undiluted extracted solution was tested (concentration = 100%)
- Controls: yes, test water without test item
- Evidence of undissolved material: no data

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Daphnia magna strauss 1820
- Source: : IRCHA-INERIS (Daphnia breeding in Décines Rhône-Poulenc laboratory)
- Age at study initiation: no data
- Weight at study initiation : no data
- Length at study initiation: 560 µm- Method of breeding: no data
- Feeding during test: no data

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

no data

Test temperature:

20.1-20.4°C

pH:

8.4

Dissolved oxygen:

92-96%

Salinity:

not applicable

Nominal and measured concentrations:

100 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml glass beaker
- Type: open
- Material, size, headspace, fill volume: 100 ml filled with 40 g of solution
- Aeration: The test medium was aerated with compressed air before the start of the test
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 1
- Biomass loading rate: 1 daphnia per 2 g of tested solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: bidistillated water
- Total organic carbon: no data
- Particulate matter: no data
- Metals: no data
- Pesticides: no data
- Chlorine: no data
- Alkalinity: NaHCO3: 0.2 g/l
- Ca/mg ratio: CaCl2,2H2O: 0.297 g/l; MgCl2,6H2O: 0.167 g/l
- other: K2SO4: 0.026 g/l
- Conductivity: 0.90 µS/cm (of the bidistillated water)
- Culture medium different from test medium: no data
- Intervals of water quality measurement: The concentration of dissolved oxygen and the pH were measured after 48 h in each test flask


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: exposure in the dark
- Light intensity: no

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The measured effect is the mortality of the daphnids estimated through their immobilisation after 24 and 48 hours of exposure


TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable (limit test)
- Justification for using less concentrations than requested by guideline: not applicable (limit test)
- Range finding study : no

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7).

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % saturated solution (initial loading rate = 100 mg/L)

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No further details given on the study results

Results with reference substance (positive control):

the 24-h EC50 for potassium dichromate was 1.4 ppm (w/w) (1.3-1.5 ppm (w/w)).

Reported statistics and error estimates:

not necessary as no adverse effect was observed

Any other information on results incl. tables

Effect of Zirconium dioxide on the Mobility of Daphnia magna:

Treatment (Loading rate)	No. of daphnids tested	Immobilized daphnids after 24 hours           No.                   %		Immobilized daphnids after 48 hours           No.                   %
Control	20	0	0	0	0
100 mg/L	20	0	0	0	0
100 mg/L	20	0	0	1	5

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Zirconium dioxide had no acute effect on Daphnia magna at an initial loading rate of 100 mg/L.

Executive summary:

The acute toxicity of zirconium dioxide to Daphnia magna was studied under static conditions according to EU method C2. Daphnids were exposed to control and test chemical at an initial loading rate of 100 mg/L for 48 hours. Mortality and immobilization were observed after 24 and 48 hours.

No significant immobilization was observed at the loading rate of 100 mg/L. The 48-h NOEC and 48-h EC50 were thus superior to this value.