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Physical & Chemical properties

Melting point / freezing point

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Reference
Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
other: Differential scanning calorimetry and metal block (capillary) method
Melting / freezing pt.:
> 450 °C
Atm. press.:
101.3 kPa
Decomposition:
ambiguous
Sublimation:
no

The test substance was heated to a maximum of 450 °C in the DSC analysis and 300 °C using a metal block analysis method. No changes indicating that the substance melted were observed (i.e. the melting point is considered to be > 450 °C).

In the metal block analysis, the substance underwent a transient color change from 190 °C (turning yellow/brown from off white), with evidence of drying observed at 206 °C. No presence of the yellow/brown color change was noted from 225 °C up to 300 °C. The cause of the color change and the wide thermal events noted in the DSC thermograms could not be conclusively explained, although these likely relate to changes in non-labile water content present in the test item’s crystal structure. Other possibilities such as decomposition, surface oxidation and rearrangement of the crystal structure itself could not be ruled out.

Conclusions:
The melting point of the test substance was deemed to be greater than the highest temperature utilised on study (450°C).

Description of key information

The melting point of the substance was considered using both DSC and capillary techniques. The test substance was heated to a maximum of 450°C in the DSC analysis and 300°C using a metal block analysis method. No changes indicating that the substance melted were observed (i.e. the melting point is considered to be > 450°C). As such, no relevant value is available as the key value for chemical safety assessment.

Key value for chemical safety assessment

Additional information