Reaction products of boric acid and calcium dihydroxide and lithium hydroxide

Density

Link to relevant study record(s)

Reference

Endpoint:

relative density

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 and are expected to have similar physiochemical properties. Any variations due to the range of trigonal and tetrahedral species between the substances are not expected to lead to any changes in the density. The target UVCB has both trigonal and tetrahedral configurations.

A density value of 2.37 g/cm3 was obtained in an experimental study on dilithium tetraborate and a similar value of 2.18 g/cm3 is quoted for lithium metaborate which confirms the similarity in density between the category members. The density of calcium metaborate was determined using the pycnometer method according to EU Method A3. The relative density of the test item was determined to be 1.904 g/cm3.
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. Read-across to the experimental study on dilithium tetraborate is therefore proposed to fill the density endpoint for the REACH registration of Reaction products of boric acid and calcium dihydroxide and lithium hydroxide.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Type:

density

Density:

2.37 g/cm³

Temp.:

20 °C

Key result

Type:

relative density

Density:

2.37 other: no units

Temp.:

20 °C

Conclusions:

The density of Reaction products of boric acid and calcium dihydroxide and lithium hydroxide should not vary considerably to the value obtained for dilithium tetraborate. The relative density of the target UVCB can therefore be quoted as 2.37. The sample density was determined to be 2370 kg/m3.

Executive summary:

The density of dilithium tetraborate was determined using the pycnometer method according to EU Method A3. The relative density of the test item was determined to be 2.37. The sample density was determined to be 2370 kg/m³. The density of Reaction products of boric acid and calcium dihydroxide and lithium hydroxide

should not vary considerably to the value obtained for dilithium tetraborate.

Description of key information

The density of dilithium tetraborate was determined using the pycnometer method according to EU Method A3. The relative density of the test item was determined to be 2.37. The sample density was determined to be 2370 kg/m³. The density of Reaction products of boric acid and calcium dihydroxide and lithium hydroxide

should not vary considerably to the value obtained for dilithium tetraborate.

Key value for chemical safety assessment

Relative density at 20C:

2.37