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Melting point / freezing point

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Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
19 July 2017 - 22 August 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
differential scanning calorimetry
Melting / freezing pt.:
> 600 °C
Atm. press.:
101.325 kPa
Decomposition:
no
Sublimation:
no
Remarks on result:
other: No melting point was recorded up to 600°C.

Assay No. 1 (isotherm at 25°C for 2 min, heating ramp: 25°C to 600°C at 10°C/min):

No melting point of the test item was recorded up to 600°C.

Assay No. 2 (isotherm at 25°C for 2 min, heating ramp: 25°C to 600°C at 10°C/min):

The second assay was similar to the first one.

No melting point of the test item was recorded up to 600°C.

Conclusions:
The melting behaviour of diytterbium trioxide was assessed according to the EU A.1 method and OECD test guideline 102 in compliance with GLP using Differential Scanning Calorimetry (DSC). No melting point of the test item was recorded up to 600°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:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Qualifier:
no guideline followed
Principles of method if other than guideline:
A special procedure was used to eliminate interaction of the material of the sample with the material of the support to determine the melting point of the oxide. The sample was heated with a tubular tungsten heater (8 mm in diameter with a 30 mm length of the working zone). The investigations were conducted in technical hydrogen or high-purity argon medium under a pressure of 3 atm. The melting point was measured with an optical pyrometer. During the measurement, the working volume was purged with gas to remove vapours of the investigated substance.
GLP compliance:
no
Type of method:
other: optical pyrometer
Melting / freezing pt.:
2 645 K
Atm. press.:
3 atm
Remarks on result:
other: 2645 ± 30 K
Melting / freezing pt.:
2 371.85 °C
Atm. press.:
3 atm
Remarks on result:
other: converted from K to °C
Conclusions:
Based on the experiments performed in this study, the melting temperature of diytterbium trioxide was found to be 2645 ± 30 K (i.e. 2371.85°C).
Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
supporting study
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 were obtained from the peer reviewed CRC handbook. No information on methodology given.
GLP compliance:
no
Type of method:
other: no data
Melting / freezing pt.:
2 355
Atm. press.:
101.325 kPa
Conclusions:
According to the peer reviewed CRC handbook, ytterbium oxide has a melting point of 2355°C.

Description of key information

In a GLP experiment assigned as key study (Klimisch 1, Demangel, 2017) and performed according to the EU A.1 method and OECD test guideline 102, no melting point of the test item was recorded up to 600°C, using Differential Scanning Calorimetry. No decomposition was observed either. The melting point was therefore considered to be > 600°C in this study. Because of the unbound value, data from literature (Mordovin et al., 1967) and the CRC Handbook of Chemistry and Physics (Haynes, 2016) were included in a weight of evidence approach together with the OECD 102 study. Mordovin et al. (1967) reported a melting point of 2645 ± 30 K for ytterbium oxide, which equals 2371.85°C. The CRC Handbook reported a melting point of 2355°C. The latter value was the lowest and was therefore taken as key value for the CSA. Both data sources were scored Klimisch 2.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:
2 355 °C

Additional information