Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 910-245-3 | CAS number: -
Melting point / freezing point
Administrative data
Link to relevant study record(s)
- Endpoint:
- melting point/freezing point
- Type of information:
- other: Expert Assessment
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Expert Assessment as opposed to experimental result
- Principles of method if other than guideline:
- Assessment
- Type of method:
- other: Assessment
- Melting / freezing pt.:
- > 500 °C
- Remarks on result:
- not measured/tested
- Executive summary:
This substance is a multi-constituent substance consisting of sodium hydroxide (215-185-5, 1310-73-2) and disodium metasilicate (229-912-9, 6834-92-0). It is the by-product of a reaction between Zircon (EC no 239-019-6) and sodium hydroxide; after hydrolysis, this substance is the water-soluble fraction. The substance as produced is predominantly (85%) water. If the water is removed, an amorphous mixture remains that is a mixture of the above-named substances. Sodium hydroxide has a melting point of over 300 °C and anhydrous disodium metasilicate over 1,000 °C; the mixture from theoretical considerations would be likely to have a melting point in excess of 500° C. It is not possible to measure accurately the melting point of substances at this temperature.
The above should be considered as an expert statement to fulfil the REACH registration requirements under Annex VII for endpoint 7.2. The melting point of this substance may therefore be stated as >500°C.
Reference
Assessment
Description of key information
From theoretical considerations would be likely to have a melting point in excess of 500° C.
Key value for chemical safety assessment
- Melting / freezing point at 101 325 Pa:
- 500 °C
Additional information
This substance is the by-product of a reaction between Zircon (EC no 239-019-6) and sodium hydroxide; after hydrolysis, this substance is the water-soluble fraction. The substance as produced is predominantly (85%) water. If the water is removed, an amorphous mixture remains that is a mixture of sodium hydroxide and disodium metasilicate. Sodium hydroxide has a melting point of over 300 °C and anhydrous disodium metasilicate over 1,000 °C; therefore the mixture from theoretical considerations would be likely to have a melting point in excess of 500° C.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
