Absolute of Cistus ladaniferus (Cistaceae) obtained from labdanum resinoid by ethanol extraction.

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:

07 - 14 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2008

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on 15 and 16 November 2017 / signed on 15 May 2018

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

< 5.1 °C

Atm. press.:

ca. 1 013 hPa

Results of the pre-test :

At room temperature, the test item was a brown very viscous and sticky, almost not flowable liquid (it flowed very slowly). At 5.1°, the test item was harder than at room temperature no more flowable but was still pierceable. At -22.9°C and -80°C, the test item was solid like ice.

Results of the Main test using DSC method:

In all runs the mass of the crucibles was the same and the crucible was visually unchanged.

In all DSC runs no event could be detected in the cooling down phase.

In the heating up phase two flat and wide events were detected. These events are endothermic but cannot be clearly identified.

The first event was observed in a range of -42.35 to -11.81 °C and the second in a range of -13.56 to 40.02 °C (evaluated with the event marker function).

These events might indicate a delay of melting or some kind of transition. Considering the complex nature of the test item and as no signs of freezing were observed, the endothermic events in the heating up phase cannot be considered as melting without ambiguity.

Therefore, the melting point of the test item has been stated based on pre-test results, as below 5.1°C (278.3 K) under these circumstances.

No observations were made which might cause doubts on the validity of the study outcome.

Conclusions:

The melting point of test substance was determined to be below 5.1°C.

Executive summary:

The melting range of the test substance was determined under GLP according to EU Method A.1 and OECD 102, using the DSC method.

A pre-test was conducted, showing that the substance was a brown very viscous and sticky, almost not flowable liquid (it flowed very slowly) at room temperature. At 5.1°, the test item was harder than at room temperature no more flowable but was still pierceable. At -22.9°C and -80°C, the test item was solid like ice.

Two determinations were conducted and replicated. In the cooling down phase no event could be detected from 20 to -70°C, therefore no signs of freezing of the test item could be detected. In the heating up phase two flat and wide endothermic events were detected between -70°C and 50°C.

The first event was observed in a range of -42.35 to -11.81°C and the second in a range of -13.56 to 40.02 °C. However, considering the complex nature of the test item and as no signs of freezing were observed during the cooling down phase, these events cannot clearly be identified. They might indicate a delay of melting or some kind of transition.

Finally, considering that in the pre-test, the test item was not frozen after a storage time of 24 hours at 5.1°C whereas it was frozen at -22.9 °C, the melting point of the test item was stated as below 5.1°C (278.3 K) under these circumstances.

Description of key information

The melting range of the test item was considered to be < 5.1°C (278.3K)

Additional information

A fully reliable GLP experimental study, conducted according to a recognized OECD/EC guidelines is available.

It is considered as a key study.