Calcium tetraborate

Endpoint summary

Description of key information

Calcium metaborate is not corrosive in the in vitro skin corrosion test according to OECD TG431. In a  Bovine Corneal Opacity and Permeability Assay (BCOP, OECD TG437), Calcium metaborate did not induce ocular irritation.

Variations in structure (trigonal vs tetrahedral) between the members of the category are not expected to lead to any changes as at physiological pH as all the substances dissociate to provide the same common compounds. Therefore all calcium borate substances will not induce ocular irritation or skin corrosion.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Justification for type of information:

An in vitro skin corrosion test has been conducted according to OECD 431 using calcium metaborate as the test item.

Calcium metaborate, as well as calcium tetraborate and all other substances in this category rapidly dissociate in aqueous media yielding the same compound, that is boric acid/borates at physiological pH. As the test item is added to moistened skin, it will be the boric acid component of the substance which will drive the skin corrosion endpoint. Read-across to the data obtained on calcium metaborate is therefore proposed negating the need for further animal testing.

A full justification document is attached to this dossier.

Irritation / corrosion parameter:

% tissue viability

Value:

94

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

not corrosive

Interpretation of results:

GHS criteria not met

Conclusions:

It can be concluded that calcium tetraborate is not corrosive and no classification is required. 

Executive summary:

An in vitro skin corrosion test has been conducted according to OECD 431 using calcium metaborate as the test item. Calcium metaborate was found to be not corrosive. 

Calcium metaborate, as well as calcium tetraborate and all other substances in this category rapidly dissociate in aqueous media yielding the same compound, that is boric acid/borates. As the test item is added directly to moistened skin, it is expected that the substance will dissociate to its constituent parts upon contact with the skin and it will be the boric acid component of the substance which will drive the skin corrosion endpoint. 

It can therefore be concluded that calcium tetraborate is not corrosive and no classification is required. 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Justification for type of information:

A Bovine Corneal Opacity and Permeability Assay (BCOP) has been conducted on calcium metaborate.

Calcium metaborate, as well as calcium tetraborate and all other substances in this category rapidly dissociate in aqueous media yielding the same compound, that is boric acid/borates at physiological pH. As the test item is added directly to the eye, it will be on contact with the aqueous environment of the eye that all members of the category will dissociate to their relevant components, boric acid and calcium ions. It will be the boric acid component of the substance which will drive the eye irritation endpoint. Read-across to the data obtained on calcium metaborate is therefore proposed for the REACH registration of calcium tetraborate negating the need for further animal testing.

A full justification document is attached below

Irritation parameter:

in vitro irritation score

Value:

-2.2

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

cornea opacity score

Value:

-3.1

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

fluorescein retention score

Value:

0.064

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

GHS criteria not met

Conclusions:

Calcium tetraborate is not an irritant and no classification is required. 

Executive summary:

In a well conducted Bovine Corneal Opacity and Permeability Assay (BCOP), calcium metaborate was topically applied to the epithelium of the bovine cornea for 4 hours. Calcium metaborate did not induce ocular irritation and the results indicated that no classification is required for eye irritation or serious eye damage. 

Calcium metaborate, as well as calcium tetraborate and all other substances in this category rapidly dissociate in aqueous media yielding the same compound, that is boric acid/borates. As the test item is added directly to the eye, it is expected that the substance will dissociate to its constituent parts upon contact with the eye and it will be the boric acid component of the substance which will drive the eye irritation endpoint. The result obtained for calcium metaborate can therefore be used as read-across data for calcium tetraborate. 

It can therefore be concluded that calcium tetraborate is not irritant and no classification is required. 

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Calcium metaborate is not corrosive in the in vitro skin corrosion test according to OECD TG431. In a  Bovine Corneal Opacity and Permeability Assay (BCOP, OECD TG437), Calcium metaborate did not induce ocular irritation. No classification is therefore required.