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Diss Factsheets
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EC number: 825-760-8 | CAS number: 39290-95-4
- 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
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Melting point / freezing point
Administrative data
Link to relevant study record(s)
- Endpoint:
- melting point/freezing point
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Study period:
- 12 September 2017
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- The method aims to investigate the temperature behaviour of tungsten zirconium hydroxide oxide. A thermogravimetric (TG) analyser together with a Differential Thermal Analysis (DTA) was used for this.
- GLP compliance:
- not specified
- Type of method:
- thermal analysis
- Remarks:
- A thermogravimetric (TG) analyser together with a Differential Thermal Analysis (DTA) was used for this.
- Decomposition:
- yes
- Decomp. temp.:
- < 800 °C
- Remarks on result:
- other: A white product was obtained after the experiment.
- Conclusions:
- TG/DTA scans prove that tungsten zirconium hydroxide oxide undergoes a decomposition process when heated from room temperature up to 800°C, the final product being a white powder.
- Endpoint:
- melting point/freezing point
- 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 based on the available handbook data for WO3 and ZrO2. The read across justification document is attached to IUCLID Section 13.
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Reason / purpose for cross-reference:
- read-across source
- Melting / freezing pt.:
- > 1 000 °C
- Remarks on result:
- other: Based on handbook data for the melting point of WO3 and ZrO2, it can be concluded that tungsten zirconium oxide has an equally high melting point (at least > 1000°C). No precise value could be derived.
- Endpoint:
- melting point/freezing point
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- no data
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- data from handbook or collection of data
- Principles of method if other than guideline:
- Data in this peer-reviewed publication were taken from many sources, including both compilations and primary literature. Where conflicts were found, the value deemed most reliable was chosen for inclusion in the handbook. Reference sources were not provided for this parameter, nor were the experimental methods.
- GLP compliance:
- not specified
- Type of method:
- other: no data
- Melting / freezing pt.:
- ca. 1 472 °C
- Conclusions:
- The melting point of tungsten(VI) oxide was reported to be 1472°C.
- Endpoint:
- melting point/freezing point
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- no data
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- data from handbook or collection of data
- Principles of method if other than guideline:
- Data in this peer-reviewed publication were taken from many sources, including both compilations and primary literature. Where conflicts were found, the value deemed most reliable was chosen for inclusion in the handbook. Reference sources were not provided for this parameter, nor were the experimental methods.
- GLP compliance:
- not specified
- Type of method:
- other: no data
- Melting / freezing pt.:
- 2 680 °C
- Conclusions:
- The melting point was reported to be 2680°C.
- Endpoint:
- melting point/freezing point
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- no data
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- data from handbook or collection of data
- Principles of method if other than guideline:
- Data in this peer-reviewed publication were taken from many sources, including both compilations and primary literature. Where conflicts were found, the value deemed most reliable was chosen for inclusion in the handbook. Reference sources were not provided for this parameter, nor were the experimental methods.
- GLP compliance:
- not specified
- Type of method:
- other: no data
- Melting / freezing pt.:
- ca. 2 710 °C
- Conclusions:
- The melting point of zirconium dioxide was reported to be 2710°C.
Referenceopen allclose all
Results:
1. One continuous weight loss of 17.64% is noticed between room temperature and 700°C. This weight loss corresponds to different processes that overlap during the thermal treatment: dehydration, dehydroxylation and removal of minor anionic impurities from processing.
2. Dehydration is an endothermic process.
3. Material crystallisation is an exothermic process, specific to this type of material demonstrated by the display of two exotherms between 500 and 650°C. Analysed batch shows a first exotherm with a maximum at 524°C and a second exotherm with a maximum at 558°C.
4. No other weight loss or phase transition occurs up to 800°C.
Description of key information
Based on melting point data available for the individual substances ZrO2 and WO3, the substance tungsten zirconium oxide can be concluded to have a high melting point (> 1000°C).
Key value for chemical safety assessment
Additional information
1. Information on zirconium dioxide
Although only two values are available from peer reviewed handbooks, it can be safely concluded that the melting point of zirconium dioxide is approximately 2700°C, rendering it environmentally irrelevant.
2. Information on tungsten(VI) oxide (WO3)
The melting point of tungsten(VI) oxide was reported to be 1472°C in a peer reviewed handbook.
3. Information on tungsten zirconium hydroxide oxide
An in-house experimental study based on TG/DTA scans performed on tungsten zirconium hydroxide oxide shows that this test item undergoes a decomposition process (mainly dehydration and dehydroxylation) when heated from room temperature up to 800°C. The final product is a white powder. Therefore, no melting point can be reported for this test material. Since this study is performed on tungsten zirconium hydroxide oxide, it is assigned as supporting study. The remaining white powder after the test can be assumed to be crystalline tungsten zirconium oxide.
4. Conclusion on tungsten zirconium oxide
Based on information on the individual components of the substance, i.e. zirconium dioxide and tungsten(VI) oxide, the melting point of tungsten zirconium oxide could also be expected to be very high (> 1000°C). The data on zirconium dioxide and tungsten trioxide were used in a weight of evidence approach to cover the endpoint.
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.
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