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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
melting point/freezing point
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
The UVCB - Reaction products of boric acid and calcium dihydroxide and lithium hydroxide (EC # 701-453-3) has structural similarities to two already established categories: lithium salts of the oxyacids of boron (B); and calcium salts of the oxyacids of boron (B). Dilithium tetraborate (EC# 234-514-3) (source substance #1) and calcium metaborate (EC# 237-224-5) (source substance #2) will be used to predict the properties for the target substance.
The target UVCB substance is made up of components from both categories and is manufactured by mixing calcium hydroxide, lithium hydroxide and boric acid in an oil medium in such a ratio that they react to form a complex mixture of lithium calcium borates as components of a colloidal mixture which is subsequently used as a lubricating grease.

All of the substances in these two categories are inorganic lithium salts/calcium salts of boric acid and are solid at ambient temperature. The melting point of these solids is high (>500 °C).The target UVCB substance has a higher precursor molar ratio for lithium hydroxide than for calcium hydroxide, and therefore the precautionary principle should be applied and read across from dilithium tetraborate where relevant to consider the worst case. Therefore the melting point of dilithium tetraborate, as well as calcium metaborate, was reported as >500 °C, while the CRC Handbook reports the melting point of lithium metaborate as 849°C. Any variations due to the range of trigonal and tetrahedral species between the substances are not expected to lead to any changes in the melting point. A result of >500 °C is therefore expected for Reaction products of boric acid and calcium dihydroxide and lithium hydroxide; read-across to the data for dilithium tetraborate is therefore proposed.
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Key result
Melting / freezing pt.:
> 500 °C
Conclusions:
The melting point of Reaction products of boric acid and calcium dihydroxide and lithium hydroxide is expected to be >500 °C.
Executive summary:

The melting point of dilithium tetraborate was determined to be >500 °C in an OECD 102. As Reaction products of boric acid and calcium dihydroxide and lithium hydroxide is also an inorganic borate substance it is expected to have a similar high melting point of >500 °C. A high melting point is consistent with the data reported in the CRC handbook for lithium metaborate (849 °C).

Description of key information

The melting point of dilithium tetraborate was determined to be >500 °C in an OECD 102. As Reaction products of boric acid and calcium dihydroxide and lithium hydroxide is also an inorganic borate substance it is expected to have a similar high melting point of >500 °C. A high melting point is consistent with the data reported in the CRC handbook for lithium metaborate (849 °C).

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:
500 °C

Additional information