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Physical & Chemical properties

Melting point / freezing point

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Reference
Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
November - December 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
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:
yes (incl. certificate)
Remarks:
This study has been performed in compliance with Good Laboratory Practice (GLP) in Switzerland, Procedures and Principles, March 1986, issued by the Federal Department of the Interior and the Intercantonal Office for the Control of Medicaments, Switzerlan
Type of method:
hot stages
Key result
Melting / freezing pt.:
>= 93.15 - <= 136.6 °C
Atm. press.:
ca. 1 013 hPa
Decomposition:
yes

A preliminary experiment suggested a melting range between about 96°C and 141°C.

Table of test results:

Substance

Melting range / °C

Individual

Expected

Bencoic acid

122.5

122.4

Average

122.45

122.35

Start

End

Phenylguanidine carbonate

93.3

136.4

93.0

136.8

Average

93.15

136.6

The expected melting point of the reference substance bencoic acid was determined to be 122.45°C with regard to expected 122.35°C.

The test substance, a carbonate salt, also contains water of crystallisation. The loss of water and of carbon dioxide during the melting process will have had an influence on the melting point. The accuracy of the determination is estimated to be about +-1.0°C

Conclusions:
The melting range of the test substance was determined to be 93.2°C - 136.6°C with thermal decomposition.
Executive summary:

The study was carried out under GLP rules.

The study was performed in accordance with the OECD Guideline for testing of chemicals, No.102, May 1981; and with the EC Guideline A.1: EG RichtlinieA.1, Amtsblatt der Europäischen Gemienschaften 84/449, Nr. L 251/4 - L 251/12, September 1984, using the hot stage method with visual determination of the melting range using the microscope. The melting range of the test substance was determined to be 93.2°C - 136.6°C with thermal decomposition.

Description of key information

The study was carried out under GLP rules.
The study was performed in accordane with the OECD Guideline for testing of chemicals, No.102, May 1981;

and with the EC Guideline A.1: EG RichtlinieA.1, Amtsblatt der Europäischen Gemienschaften 84/449, Nr. L 251/4 - L 251/12, September 1984, using the hot stage method with visual determination of the melting range using the microscope. The melting range of the test substance was determined to be 93.2°C - 136.6°C with thermal decomposition.

Key value for chemical safety assessment

Additional information