Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
basic toxicokinetics 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 toxicokinetic assessment was performed based on data available for calcium metaborate. Based on the physical/chemical properties of calcium metaborate, absorption factors for this substance are derived to be 100% (oral), 100% (inhalation of aqueous aerosols) and 0.5% (dermal absorption from aqueous solutions) for risk assessment purposes. The bioaccumulation potential is expected to be low.

As calcium tetraborate has similar physicochemical properties ie. low vapour pressure and soluble in water then it is expected that the toxicokinetics assessment would be similar if not identical for calcium tetraborate especially since all absorption factors derived were based on evidence for boric compounds such as boric acid. Both the inorganic borates, calcium metaborate and calcium tetraborate, will be converted to boric acid at physiological pH in the aqueous layer on the surfaces of the mucosa. Boric acid is known to be readily taken up from the gastrointestinal tract in rats and humans, as demonstrated by experimental evidence in both human and animal studies, where more than 90% of the administered dose of borate was excreted as boric acid.

Sufficient evidence therefore exists to propose the same absorption factors for the toxicokinetics assessment. Read-across to calcium metaborate is proposed.
Conclusions:
A toxicokinetics assessment was performed using the available data for calcium metaborate. Calcium tetraborate is sufficiently similar in terms of physicochemical properties and behaviour upon absorption that the same absorption factors can be used.
Executive summary:

A toxicokinetic assessment was performed based on data available for calcium metaborate. Based on the physical/chemical properties of calcium metaborate, absorption factors for this substance are derived to be 100% (oral), 100% (inhalation of aqueous aerosols) and 0.5% (dermal absorption from aqueous solutions) for risk assessment purposes. The bioaccumulation potential is expected to be low.

As calcium tetraborate has similar physicochemical properties ie. low vapour pressure and soluble in water then it is expected that the toxicokinetics assessment would be similar if not identical for calcium tetraborate especially since all absorption factors derived were based on evidence for boric compounds such as boric acid.  Both the inorganic borates, calcium metaborate and calcium tetraborate, will be converted to boric acid at physiological pH in the aqueous layer on the surfaces of the mucosa. Boric acid is known to be readily taken up from the gastrointestinal tract in rats and humans, as demonstrated by experimental evidence in both human and animal studies, where more than 90% of the administered dose of borate was excreted as boric acid.  

Sufficient evidence therefore exists to propose the same absorption factors for the toxicokinetics assessment for calcium tetraborate.

Description of key information

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
0.5
Absorption rate - inhalation (%):
100

Additional information