Iotroxic acid

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:

2018-02-08 to 2018-05-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

GLP compliance:

no

Type of method:

other: Differential scanning calorimetry and capillary method to verify result

Key result

Melting / freezing pt.:

>= 100 - <= 230 °C

Decomposition:

yes

Remarks on result:

other: The test item melted under decomposition within a range of 100 - 230 °C

Melting point / melting range: DSC measurement

A DSC measurement showed a multistage endothermal effect in the temperature range of 100 - 230 °C with no clear melting point (onset). The endothermal effect was followed by an exothermal effect in the temperature range of 240 - 300 °C. The result of the DSC measurement is shown in Table 1.

Table 1: Melting point (DSC measurement)

Test item / mg	Starting temperature / °C	Final test temperature / °C	Temperature range (endothermal) / °C	Onset (melting) / °C	Crucible	Observations after the measurement
12.52	25	500	100 – 230	Multi-stage	Aluminium with hole	Black residue

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

Melting point / melting range: Capillary tube in a metal block

A measurement with the capillary method was performed to clarify the results of the DSC measurements. Since this measurement was performed only as a verifying screening a high heating rate of 10 K/min was chosen and therefore the absolute temperature values derived with the capillary method are not as accurate as the DSC results. The filling height of the test item was approximately 5 mm. The results are summarized in Table 2.

Table 2: Results of capillary method

Set point / °C	Heating rate / K/min	End point / °C	Remarks
50	10	230	Approx. 122 °C: test item started to melt Approx. 182 °C: test item was completely melted and turbid Approx. 199 °C: test item was a clear melt with small bubbles Approx. 224 °C: test item discoloured to orange, increasing formation of small bubbles Approx. 230 °C: no further change

Under consideration of the results from the DSC measurement and the capillary method it was concluded that the test item melted under decomposition within a range of 100 - 230 °C.

Conclusions:

The test item melted under decomposition within a range of 100 – 230 °C.

Executive summary:

The melting point / melting range of the test item was determined by DSC measurement and capillary method according to OECD test guideline 102. Under consideration of the results from the DSC measurement and the capillary method it was concluded that the test item melted under decomposition within a range of 100 - 230 °C.

Description of key information

The melting point / melting range of the test item was determined by DSC measurement and capillary method according to OECD test guideline 102. Under consideration of the results from the DSC measurement and the capillary method it was concluded that the test item melted under decomposition within a range of 100 - 230 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

100 °C