Reaction mass of copper oxide and manganese dioxide

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental phase: 2017-01-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

COMMISSION REGULATION (EC) No 440/2008 of 30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

thermal analysis

Specific details on test material used for the study:

The test item was tested as received. No further preliminary treatment such as drying or milling was performed.

Key result

Melting / freezing pt.:

> 500 °C

Decomposition:

no

Two DSC measurements with a heating rate of 10 K/min showed an endothermal effect in the temperature range of 160 – 475 °C. The results of the DSC measurements are summarized in the following Table:

Ident No.	Test item / mg	Starting temperature / °C	Final test temperature / °C	Temperature range (endo-thermal)/ °C	Onset (melting) / °C	Crucible	Observations after the measurement
36008	21.63	25	500	160 – 460	---	Aluminium with a hole	Test item unchanged after the measurement Mass loss: 7 %
36009	12.94	25	500	210 – 475	---	Aluminium with a hole	Test item unchanged after the measurement Mass loss: 5 %

An optical inspection after the measurements showed that the test item was unchanged and a mass loss of approximately 6 % occured. Due to these observations it can be concluded that the test item had no melting point under atmospheric conditions up to 500 °C. The endothermal effect could have been caused by a reaction (e.g. transformation) of one of the metal oxides.

Conclusions:

The test item had no melting point under atmospheric conditions up to 500 °C.

Executive summary:

In a guideline study compliant with GLP, the melting point / melting range was determined by differential scanning calorimetry (DSC). The test item and the reference were heated up from the starting temperature to the final temperature (500°C) at a constant heating rate (10°K/min) in a defined atmosphere (nitrogen). Open crucibles were used as containers for the test item and as empty reference crucible. The quantity of heat absorbed or released was measured and recorded.

The test item showed an endothermal effect in the temperature range of 160 – 475 ° C: first measurement -277.85 J/g; second measurement -283.06 J/g; mean value -280 J/g.

An optical inspection after the measurements showed that the test item was unchanged and a mass loss of approximately 6 % occured. Due to these observations it can be concluded that the test item had no melting point under atmospheric conditions up to 500 °C. The endothermal effect could have been caused by a reaction (e.g. transformation) of one of the metal oxides.

Description of key information

The test item had no melting point under atmospheric conditions up to 500 °C (OECD 102, differential scanning calorimetry; RL1, 2017).

Melting point >500°C;

The key value is given as 500 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

500 °C

Additional information

In a guideline study compliant with GLP, the melting point / melting range was determined by differential scanning calorimetry (DSC). The test item and the reference were heated up from the starting temperature to the final temperature (500°C) at a constant heating rate (10°K/min) in a defined atmosphere (nitrogen). Open crucibles were used as containers for the test item and as empty reference crucible. The quantity of heat absorbed or released was measured and recorded.

The test item showed an endothermal effect in the temperature range of 160 – 475 ° C.