Registration Dossier

Physical & Chemical properties

Melting point / freezing point

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2018-03-28 to 2018-05-30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Deviations:
no
GLP compliance:
no
Type of method:
differential scanning calorimetry
Specific details on test material used for the study:
The sample was tested as received. No further preliminary treatment such as drying or milling was performed. The results given in this report only apply to the tested sample.
Key result
Atm. press.:
1 013.25 hPa
Decomposition:
yes
Decomp. temp.:
>= 200 °C

Melting point / melting range

Two DSC measurements in aluminium crucibles with a hole showed an ambiguous endothermal effect after the melting in the temperature range of 260 - 285 °C.

 

DSC measurements

Test
item /
mg

Starting
temperature /
°C

Final test
temperature /
°C

Temperature
range (endo-
thermal) /
°C

Onset /
°C

Crucible

Observations

after the
measurement

11.07

25

500

260-285

multi-
stage

Aluminium
with a hole

Test item was
discoloured to
black, mass
loss 94 %

21.18

25

280

260 - 280

multi-
stage

Aluminium
with a hole

Test item was
discoloured to
black, mass
loss 71 %

An additional measurement with the capillary method was performed in order to clarify the melting
range and boiling range.

 

Results of the capillary method

No.

Set
point /
°C

Heating
rate /
K/min

End
point /
°C

Remarks

1

200

10

300

Approx. 200 °C: test item appeared melted

Approx. 225 °C: starting formation of bubbles

Approx. 235 °C: test item discoloured to orange

Approx. 250 °C: test item rose in the capillary and left the

observation window

2

30

10

200

Approx. 30 °C. test item appeared unchanged

Approx. 79 °C: test item started to melt

Approx. 132 °C; test item clear, appeared melted

Approx. 200 °C: no further changes, upon inspection the
test item was still highly viscous

 

The test item was a waxy solid. According to information from the sponsor it tends to be inhomogeneous with small inclusions of solvent. Under consideration of the results from the DSC measurements, the capillary method and the aforementioned properties it was concluded that the test item exhibited a phase transition around 80 °C (value is subject to a uncertainty of approx. 10 K due to high heating rate). The observed bubbles could have been caused by the release of minor quantities of residual solvent (see also certificate of analysis). As the DSC measurements showed no endothermal effects below 260 °C it had to be assumed that the test item had no melting point.

 

The formation of bubbles above 200 °C might indicate boiling or decomposition or both. Under consideration of the results from the DSC measurements and the capillary method it was concluded that the test item started to decompose under possible boiling above 200 °C.

Conclusions:
The test item showed no distinctive melting. The test item undergoes a phase transition at 80 °C and has not melting point up to the decomposition temperature of 200 °C.
Executive summary:

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OCSPP test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry. The test item was weighed out into an aluminium crucible under an inert atmosphere (nitrogen). Two tests with about 11 – 21 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a waxy solid at ambient conditions. The crucibles were heated up from room temperature to 500 °C and 280 °C respectively. Two DSC measurements showed an ambiguous endothermal effect after the melting in the temperature range of 260 - 280 °C. An additional measurement with the capillary method was performed in order to clarify the melting range. Since this measurement was performed only as a verifying screening a high heating rate of 10 K/min was chosen. The filling height of the test item was approximately 5 mm. Under consideration of the results from the DSC measurements, the capillary method and the aforementioned properties it was concluded that the test item exhibited a phase transition around 80 °C. The test item showed no distinctive melting. The test item undergoes a phase transition at 80 °C and has not melting point up to the decomposition temperature of 200 °C.

Description of key information

The test item showed no distinctive melting. The test item undergoes a phase transition at 80 °C and has not melting point up to the decomposition temperature of 200 °C (reference 4.2-1).

Key value for chemical safety assessment

Additional information

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OCSPP test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry (reference 4.2-1). The test item was weighed out into an aluminium crucible under an inert atmosphere (nitrogen). Two tests with about 11 – 21 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a waxy solid at ambient conditions. The crucibles were heated up from room temperature to 500 °C and 280 °C respectively. Two DSC measurements showed an ambiguous endothermal effect after the melting in the temperature range of 260 - 280 °C. An additional measurement with the capillary method was performed in order to clarify the melting range. Since this measurement was performed only as a verifying screening a high heating rate of 10 K/min was chosen. The filling height of the test item was approximately 5 mm. Under consideration of the results from the DSC measurements, the capillary method and the aforementioned properties it was concluded that the test item exhibited a phase transition around 80 °C. The test item showed no distinctive melting. The test item undergoes a phase transition at 80 °C and has not melting point up to the decomposition temperature of 200 °C.