Tungsten oxide

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Data from peer-reviewed handbook or collection of data. Due to the similar chemical constituency and structure, the physico-chemical properties would be expected to the the same or sufficiently similar such that application of this read-across is appropriate.

Justification for type of information:

1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Tungsten trioxide
Target: Tungsten oxide
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

read-across: supporting information

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 was the experimental method.

GLP compliance:

not specified

Key result

Melting / freezing pt.:

1 472 °C

Sublimation:

yes

Remarks:

: significant sublimation at >750 °C

Executive summary:

No melting point data of sufficient quality are available for tungsten oxide (target substance). However, data are available for tungsten trioxide (source substance), which are used for read-across. Due to lower water solubility and lower toxicity for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate as a conservative estimate of potential toxicity for this endpoint. In addition, read-across is appropriate because the classification and labelling is more protective for the source substance than the target substance, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, lower for the source substance. For more details, refer to the read-across category approach in the Category section of this IUCLID submission or Annex 3 in the CSR. 

Reference 2

Endpoint:

melting point/freezing point

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Data from peer-reviewed handbook or collection of data. Due to the similar chemical constituency and structure, the physico-chemical properties would be expected to the the same or sufficiently similar such that application of this read-across is appropriate.

Justification for type of information:

1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Tungsten trioxide
Target: Tungsten oxide
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

reference to same study

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 was the experimental method.

GLP compliance:

not specified

Key result

Melting / freezing pt.:

1 472 °C

Atm. press.:

1 013 hPa

Sublimation:

yes

Assumed to be performed under standard conditions. Pressure not given.

Executive summary:

No melting point data of sufficient quality are available for tungsten oxide (target substance). However, data are available for tungsten trioxide (source substance), which are used for read-across. Due to lower water solubility and lower toxicity for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate as a conservative estimate of potential toxicity for this endpoint. In addition, read-across is appropriate because the classification and labelling is more protective for the source substance than the target substance, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, lower for the source substance. For more details, refer to the read-across category approach in the Category section of this IUCLID submission or Annex 3 of the CSR. 

Reference 3

Endpoint:

melting point/freezing point

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Data from peer-reviewed handbook or collection of data. Due to the similar chemical constituency and structure, the physico-chemical properties would be expected to the the same or sufficiently similar such that application of this read-across is appropriate.

Justification for type of information:

1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Tungsten trioxide
Target: Tungsten oxide
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR

Reason / purpose for cross-reference:

read-across: supporting information

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 was the experimental method.

GLP compliance:

not specified

Key result

Melting / freezing pt.:

1 473 °C

Atm. press.:

1 013 hPa

Remarks on result:

other: assumed to be conducted under standard conditions

Due to the similar chemical constituency and structure, the physico-chemical properties would be expected to be the same or sufficiently similar such that application of this read-across is appropriate for this endpoint. For more details, refer to the read-across category approach in the Category section of this IUCLID submission or Annex 3 of the CSR.

Executive summary:

No melting point data of sufficient quality are available for tungsten oxide (target substance). However, data are available for tungsten trioxide (source substance), which are used for read-across. Due to lower water solubility and lower toxicity for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate as a conservative estimate of potential toxicity for this endpoint. In addition, read-across is appropriate because the classification and labelling is more protective for the source substance than the target substance, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, lower for the source substance. For more details, refer to the read-across category approach in the Category section of this IUCLID submission or Annex 3 of the CSR. 

Description of key information

The melting point is estimated to be near 1472°C, based on read-across to tungsten trioxide.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

1 472 °C

Additional information

Due to the similar chemical constituency and structure, the physico-chemical properties would be expected to the same or sufficiently similar such that application of this read-across is appropriate for this endpoint. For more details, refer to the attached read-across approach document on Annex 3 in the CSR.