Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 939-960-9 | CAS number: 39318-32-6
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Short-term toxicity to aquatic invertebrates
Administrative data
Link to relevant study record(s)
- Endpoint:
- short-term toxicity to aquatic invertebrates
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- September 23-25, 2005
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: Not a GLP study. Also, test material is diluted to 60% in aqueous suspension so the results were recalculated to represent 100% magnesium hydroxide.
- Qualifier:
- according to guideline
- Guideline:
- other: Methods for measuring the acute toxicity of effluents and receiving waters to freshwater and marine organisms. 5th ed., October 2002, EPA Volume 821-R-02-012. Test method 2021.0, Daphnia pulex and Daphnia magna acute toxicity tests.
- GLP compliance:
- no
- Vehicle:
- no
- Test organisms (species):
- Daphnia magna
- Test type:
- static
- Water media type:
- freshwater
- Limit test:
- no
- Total exposure duration:
- 48 h
- Test temperature:
- 20 +/- 1°C
- Nominal and measured concentrations:
- A control plus seven chemical concentration exposures were tested: 96.88 mg/L; 193.75 mg/L; 387.5 mg/L; 775 mg/L; 1550 mg/L; 3100 mg/L; and 6200 mg/L.
- Details on test conditions:
- TEST SYSTEM
- Test vessel: cups
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 30-mL plastic cups, fill volume 25 mL
- 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
TEST MEDIUM / WATER PARAMETERS
- Intervals of water quality measurement: daily
OTHER TEST CONDITIONS
- Photoperiod: 16L:8D
- Light type: fluorescent lighting
EFFECT PARAMETERS MEASURED (with observation intervals if applicable): survival, daily - Duration:
- 48 h
- Dose descriptor:
- LC50
- Effect conc.:
- 284.76 mg/L
- Conc. based on:
- test mat.
- Basis for effect:
- mortality
- Remarks on result:
- other: for test material with 60% Mg(OH)2
- Duration:
- 96 h
- Dose descriptor:
- LC50
- Effect conc.:
- 170.86 mg/L
- Conc. based on:
- act. ingr.
- Basis for effect:
- mortality
- Remarks on result:
- other: recalculated to 100% Mg(OH)2
- Conclusions:
- In a 48 hour acute static definitive toxicity test with Daphnia magna, the LC50 value was determined to be 284.76 mg of test substance (60% Mg(OH)2 aqueous suspension). The recalculated LC50 (48h) with pure magnesium hydroxide for D. Magna was determined as 170.86 mg/L.
- Endpoint:
- short-term toxicity to aquatic invertebrates
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- 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 C.2 and was GLP-compliant. However, no analytics were performed.
- Qualifier:
- according to guideline
- Guideline:
- EU Method C.2 (Acute Toxicity for Daphnia)
- Deviations:
- not specified
- GLP compliance:
- yes
- Analytical monitoring:
- no
- 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 (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 - Test type:
- static
- Water media type:
- freshwater
- Limit test:
- yes
- Total exposure duration:
- 48 h
- 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 (nominal loading rate)
- 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).
- 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.
- 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 C.2. 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 with the loading rate of 100 mg/L. The 48-h NOEC and 48-h EC50 were thus superior to this value.
- Endpoint:
- short-term toxicity to aquatic invertebrates
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- weight of evidence
- Justification for type of information:
- Read across from a study performed with zirconium dioxide in combination with one study performed with magnesium dihydroxide. The read across justification document is attached in IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Key result
- Remarks on result:
- other: Magnesium zirconium oxide is not considered to be toxic or harmful to aquatic invertebrates.
- Remarks:
- This conclusion was based on the results of the study from Bazin (1994) with zirconium dioxide, the results of the study of Heinen et al. (2005) with magensium dihydroxide, and the limited water solubility of magnesium zirconium oxide.
Referenceopen allclose all
Survival of D. magna was 100 percent in the control exposure. After 48 hours of exposure to serial dilutions of the test solution, survival of D. magna in the test exposures ranged from 0 percent (concentration 6200 mg/L test substance) to 95 percent (96.88 mg/L test substance).
Table 1. Percent survival of D. magna at the conclusion of acute toxicity tests using dilutions of the test substance
Control or chemical exposure |
Concentration of test substance (mg/L) |
Survival (%) after 48 hours |
mg/L LC50 |
Control |
0 |
100 |
284.76 |
Test substance |
96.88 |
95 |
|
Test substance |
193.75 |
70 |
|
Test substance |
387.5 |
25 |
|
Test substance |
775 |
5 |
|
Test substance |
1550 |
15 |
|
Test substance |
3100 |
5 |
|
Test substance |
6200 |
0 |
Water quality measurements remained within acceptable ranges throughout the duration of both toxicity
tests in virtually all replicates. Occasional deviations in temperature were observed during the test but these minor deviations did not appear significant. The LC50 (48h) for D. magna was recalculated to give a more accurate result with 100% concentration of magnesium hydroxide as the original LC50 was calculated with a 60% magnesium hydroxide concentration. The recalculated LC50 (48h) for D. magna was determined to be 170.86 mg/L.
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 |
Description of key information
The endpoint is covered by a weight of evidence approach including one short-term study for zirconium dioxide (Bazin, 1994) and one short-term study for magnesium hydroxide (Heinen, 2005). Zirconium dioxide did not cause any adverse effects in daphnids up to and including the limit test concentration of 100 mg/L (nominal loading rate). The study performed with magnesium hydroxide is considered relevant for magnesium oxide because magnesium oxide, upon dissolution in water, is transformed to magnesium hydroxide. The LC50 for Mg(OH)2 was determined to be 170.86 mg/L. Taking into account these key data for zirconium dioxide and magnesium hydroxide, magnesium zirconium oxide can be concluded to be not toxic or harmful to aquatic invertebrates either.
Key value for chemical safety assessment
Additional information
1. Information on zirconium dioxide
In a study from Bazin (1994), 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. No significant immobilization was observed up to and including the loading rate of 100 mg/L. The 48-h EC50 was thus superior to this value.
2. Information on magnesium oxide
For magnesium oxide, data obtained from a test performed with magnesium hydroxide were added to the dossier. The rationale behind this is that in the environment, MgO will result in Mg(OH)2 formation when in contact with water, according to the following (general) reaction:
MgO + H2O <--> Mg(OH)2
A study performed with a 60% aqueous solution of Mg(OH)2 was added to the weight of evidence approach. The study is a short-term toxicity test with Daphnia magna (Heinen, 2005) which was carried out according to a US EPA test method. The recalculated 48-h LC50 for pure Mg(OH)2 was determined to be 170.86 mg/L.
3. Conclusion on magnesium zirconium oxide
Magnesium zirconium oxide is zirconium dioxide with magnesium partly replacing zirconium in the crystal lattice. Since both zirconium dioxide and magnesium hydroxide (which is formed when magnesium oxide is in contact with water) are - based on the results of the available key studies for these substances - not to be classified as toxic or harmful to aquatic invertebrates, it was concluded that magnesium zirconium oxide is not expected to be toxic or harmful to aquatic invertebrates either. This confirms the read across assumption that the addition of magnesium (oxide) to the crystal lattice of zirconium dioxide does not alter the unhazardous character of zirconium dioxide.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.