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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
Study period:
23-07-2019 to 13-08-2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study performed under GLP. All relevant validity criteria were met.
Qualifier:
according to
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7200 (Melting Point / Melting Range)
Deviations:
no
GLP compliance:
yes
Type of method:
differential scanning calorimetry
Melting / freezing pt.:
ca. -11.5 °C
Atm. press.:
ca. 1 010 hPa
Decomposition:
no
Sublimation:
no
Remarks on result:
other: mean melting point (n = 2)

Main study

- Experiment 1: During cooling, an exothermic effect between -20°C and -40°C was observed, which was due to crystallization of the test item. During heating, an endothermic effect between -25°C and 0°C was observed, followed by another endothermic effect between 200°C and 300°C. The extrapolated onset temperature of the second effect was 273.622°C.

- Experiment 2: Was conducted to examine the second endothermic effect by using a higher heating rate of 50°C/minute. The first endothermic peak shifted to higher temperatures, whilst the second did not, demonstrating that evaporation of the test substance was the reason for the endothermic effect. Since a higher heating rate was used, the extrapolated onset temperature of the second endothermic effect was not used in the calculation of the boiling point.

- Experiment 3: Was conducted to further examine the boiling temperature of the test item in duplicate. An endothermic peak was observed. The extrapolated onset of the evaporation peak was 263.995°C. The difference in extrapolated onset between experiment 1 and 3 was >1°C, therefore the test item may have evaporated before boiling due to a lower sample amount.

- Experiment 4: Was conducted to further examine the boiling temperature of the test item as a duplicate of experiment 3. The experiment was conducted under the same conditions as experiment 4, but with a higher sample amount. The extrapolated onset of the boiling peak was 274.326°C.

The melting temperature was determined as the mean melting temperature of Experiment 1 (-11.223°C) and Experiment 2 (-11.734°C).

Conclusions:
The melting temperature was -11.5°C (or 261.65K).
Executive summary:

The melting temperature was determined according to EU Method A.1 and OECD TG 102 using the Differential Scanning Calorimetry method under GLP. The guideline defines the melting temperature as: the temperature at which the phase transition from solid to liquid state occurs at atmospheric pressure and this temperature ideally corresponds to the freezing temperature. During DSC cooling an exothermic effect was observed between -20°C and -40°C, due to crystallization of the test item. The melting temperature was determined to be -11.5°C (or 261.65K).

Description of key information

Mp: -11.5 °C ( or 261.65 K) at 1 atmosphere, OECD TG 102 - DSC Method, 2019

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:
-11.5 °C

Additional information

Key study : EU Method A.1, 2019 : The melting temperature was determined according to EU Method A.1 and OECD TG 102 using the Differential Scanning Calorimetry method under GLP. The guideline defines the melting temperature as: the temperature at which the phase transition from solid to liquid state occurs at atmospheric pressure and this temperature ideally corresponds to the freezing temperature. During DSC cooling an exothermic effect was observed between -20°C and -40°C, due to crystallization of the test item. The melting temperature was determined to be -11.5°C (or 261.65K).