Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

No skin sensitization studies with Dipotassium Tetraborates were available however the data indicate that these borates are not sensitizers. Disodium tetraborate decahydrate and disodium tetraborate pentahydrate were tested in a Buehler method skin sensitisation test (Wnorowski, 1994) applied at a concentration of 95 % (powder moistened with water) during both the induction and challenge phase of the test.

Read Across

A number of these studies were conducted on an analogue substance. Read-across is justified on the following basis:

In aqueous solutions at physiological and acidic pH, low concentrations of simple inorganic borates such as boric acid B(OH)3, potassium pentaborate (K2B10O16.8H2O), potassium tetraborate (K2B4O7.4H2O), disodium tetraborate decahydrate (Na2B4O7.10H2O; borax), disodium tetraborate pentahydrate (Na2B4O7.5H2O; borax pentahydrate), boric oxide (B2O3) and disodium octaborate tetrahydrate (Na2B8O13.4H2O) will predominantly exist as undissociated boric acid. Above pH 9 the metaborate anion (B(OH)4-) becomes the main species in solution (WHO, 1998). This leads to the conclusion that the main species in the plasma of mammals and in the environment is undissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as undissociated boric acid under the same conditions.

For comparative purposes, exposures to borates are often expressed in terms of boron (B) equivalents based on the fraction of boron in the source substance on a molecular weight basis. Some studies express dose in terms of B, whereas other studies express the dose in units of boric acid. Since the systemic effects and some of the local effects can be traced back to boric acid, results from one substance can be transferred to also evaluate the another substance on the basis of boron equivalents. Therefore data obtained from studies with these borates can be read across in the human health assessment for each individual substance. Conversion factors are given in the table under CSR section 5.1.3, which corresponds to IUCLID section 7.1 (toxicokinetics, metabolism and distribution endpoint summary).

References:

WHO. Guidelines for drinking-water quality, Addendum to Volume 1, 1998


Migrated from Short description of key information:
No skin sensitization studies with Dipotassium Tetraborates were available however the data indicate that these borates are not sensitizers. Skin sensitisation tests on disodium tetraborate decahydrate and disodium tetraborate pentahydrate were performed according to OECD Guideline 406 (Buehler method).

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

There are no data to suggest that dipotassium tetraborate is a respiratory sensitiser.


Migrated from Short description of key information:
There are no data to suggest that dipotassium tetraborate is a respiratory sensitiser.

Justification for classification or non-classification

Dipotassium tetraborate is not a skin or respiratory sensitiser.