Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Melting point / freezing point

Currently viewing:

Administrative data

Link to relevant study record(s)

melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Testing was conducted between 31 March 2010 and 24 August 2010.
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
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. The study report was conclusive and done to a valid guideline.
according to guideline
EU Method A.1 (Melting / Freezing Temperature)
GLP compliance:
Type of method:
differential scanning calorimetry
Key result
Melting / freezing pt.:
>= 723 K
Remarks on result:
other: No atmospheric pressure was recorded for this endpoint.


Please see Attachment 1 for Thermograms and thermographic data for Determinations 1 and 2.

The melting/freezing temperature of the test item has been determined to be not less than 450°C (723K).
Executive summary:


General physico-chemical properties of the test item have been determined.

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


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


The melting/freezing temperature of the test item has been determined to be not less than 450°C (723K).

Description of key information

Melting point/freezing point (HEDP acid): >450°C (Tremain 2010). This conclusion may be read across to the salt.

Key value for chemical safety assessment

Additional information

The acid form of HEDP has been demonstrated not to melt below 450ºC. The DSC thermograms show evidence of loss of water at about 100°C. This result has been reported in an up to date study which was conducted by differential scanning calorimetry (DSC) using ASTM E537-86 method. The result is considered as reliable and has therefore been assigned as key study. The sodium salt of HEDP would be expected to melt at a higher temperature than the acid. This conclusion is supported by available data for HEDP-4Na which indicates that the test substance shows no melting up to 500°C at 1013 hPa.