Calcium hydrogenorthophosphate

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:

Testing was conducted between 30 September 2009 and 12 November 2009.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of GLP inspection: 2009-09-15 Date of Signature on GLP certificate: 2009-11-26

Type of method:

other: Differential scanning calorimetry (DSC) using the procedure specified in ASTM E537-86

Melting / freezing pt.:

> 723 K

Remarks on result:

other: .

Thermograms and thermographic data for Determinations 1 and 2 are shown in
the following tables respectively.

Thermographic Data – Determination 1

Thermal Event	Interpretation	Temperature
		ºC	K
Onset of endotherm	Loss of volatiles	~320	~593

Thermographic Data – Determination 2

Thermal Event	Interpretation	Temperature
		ºC	K
Onset of endotherm	Loss of volatiles	~320	~593

Overall result (based on Determinations 1 and 2):

Melting temperature greater than 450°C (723 K). The test material underwent loss of volatile components from approximately 593 K.

Please see Attachment "Thermogram – Determination's" for Thermogram – Determination's.

Conclusions:

The test material was determined to have a melting temperature greater than 723 K. The test material was identified as undergoing loss of volatiles, most likely water, due to dehydration of the test material, from approximately 593 K. However, this thermal event was not associated with a phase transition (i.e. melting) of the test material.

This study is conducted according to an appropriate guideline and under the conditions of GLP and therefore the study is considered to be acceptable and to adequately satisfy both the guideline requirement and the regulatory requirement as a key study for this endpoint.

Executive summary:

Summary

The test material was determined to have a melting temperature of greater than 723 Kby differential scanning caloritry, using ASTM E537-86,Method A1 Melting/Freezing Temperature of Commission Regulation (EC) No 440/2008 of 30 May 2008. The test material was identified as undergoing loss of volatiles/dehydration from approximately 593 K, however, this thermal event was not associated with a phase transition (i.e. melting) of the test material.

Introduction

The melting/freezing temperature and water solubility of the test material have been determined.

Methods employed complied with those specified in Commission Regulation (EC) No 440/2008 of 30 May 2008, Part A: Methods for the determination of physico-chemical properties.

Method

The determination was carried out by differential scanning calorimetry (DSC) using the procedure specified in ASTM E537-86, Method A1 Melting/Freezing Temperature ofCommissionRegulation (EC) No 440/2008 of 30 May 2008.

Result

Overall result (based on Determinations 1 and 2):

Melting temperature greater than 450°C (723 K). The test material underwent loss of volatile components from approximately 593 K.

Conclusion

The test material was determined to have a melting temperature greater than 723 K. The test material was identified as undergoing loss of volatiles, most likely water, due to dehydration of the test material, from approximately 593 K. However, this thermal event was not associated with a phase transition (i.e. melting) of the test material.

Description of key information

 Melting point: > 450 °C (EU Method A.1, OECD 102, GLP)

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

450 °C

Additional information

The test material was determined to have a melting temperature greater than 723 K. The test material was identified as undergoing loss of volatiles, most likely water, due to dehydration of the test material, from approximately 593 K. However, this thermal event was not associated with a phase transition (i.e. melting) of the test material.