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

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21-22 February 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

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 but restrictions apply considering the difficulty to determine the initial boiling point & temperature of decomposition of the substance. Therefore a validation with restrictions applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling point/boiling range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling 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:

method according to Siwoloboff

Decomposition:

ambiguous

Remarks on result:

not determinable

Pre-test:

Table 4.3.1: Observations Pre-test

Observations	Temperatures
Colourless condensate visible	Since 150 °C
Small bubbles in large interval	Since 170°C
More bubbles	Since 230°C
Superheating	236 °C
Superheating with bubble chain, gas burner switched off, colour slightly darker	268.8 °C
Superheating	259.9°C, 254.6°C
Bubble chain broke	249.8°C

After cooling down the colour of the test item was slightly darker.

Main test following Siwoloboff

Observations and measured values are presented in the following table:

Table 4.3.2: Observations main test following Siwoloboff

Observations	Temperatures
	First Determination atmospheric pressure 100067 Pa	Second Determination atmospheric pressure 99773 Pa
Test start: The test item was more liquid, fine small bubbles visible and which vanish a short time later	145.0 °C	145.0 °C
Colourless condensate	Since 148°C	Since 145,4°C
One bubble	-	156°C
Individual bubble with large interval	Since 155°C	Since 200°C
Bubbles vanish	Since 160°C	-
Individual bubble visible again	200°C	-
More bubbles	Since 210 °C	Since 215 °C
Condensate dropped, 3 times superheating	214.8 °C	-
Superheating, due to safety reasons gas burner switched off after informing of the study director	218.5 °C	-
Condensate dropped, 2 times superheating, gas burner switched off	-	227.1 °C

Considering that superheating (indicated by the substance (strongly) spraying out of the container) was observed from approximately at 214.8 °C (lowest value first determination) and 227.1°C (second determination) respectively, the test has been stopped for safety reasons. Finally no boiling point could be detected using the SIWOLOBOFF method.

After cooling down the colour of the test item was slightly darker.

Colour change, violent superheating and small bubbles / colourless condensate observed from 145°C, may be either the sign of decomposition of the substance or the sign of releasing of trapped more volatile compounds in the matrix.

No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

 

Conclusions:

No boiling point can be determined using the Siwoloboff method and signs of potential decomposition of the substance were observed during the tests.

Executive summary:

A reliable GLP experimental study, conducted according to a recognized OECD/EC guidelines is available. It is considered as a key study.

A pre-test was performed to estimate the initial boiling point of the substance at approximately 249.8°C.

Then, the Siwoloboff method was performed to determine the initial boiling point of the substance. However, the test has been stopped for safety reasons due to strong superheating from 214.8 / 227.1 °C (first and second determination respectively).

After cooling down the colour of the test item was slightly darker. This colour change, violent superheating and small bubbles / colourless condensate observed from 145°C, may be either the sign of decomposition of the substance or the sign of releasing of trapped more volatile compounds in the matrix.

Finally no temperature of initial boiling point or initial decomposition of the test item has been determined using this method.

Description of key information

No boiling point can be determined using Siwoloboff method and signs of potential decomposition of the test item were observed during the test.

Additional information

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

It is considered as a key study.