Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 701-311-0 | CAS number: -
Endpoint summary
Administrative data
Link to relevant study record(s)
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
EC 701 -311 -0 is not vaporized or aerosolized during manufacture and use so inhalation is not a relevant route of exposure. Oral is not a route of exposure for workers either and so the only relevant route of exposure is dermal. Worst case dermal absorption assumptions would estimate equal absorption to boric acid. Boric acid is not absorbed dermally with <0.5% percutaneous absorption in human. Therefore, the toxicokinetic considerations are minimized based on exposure considerations. As a worst case example, boric acid is used as read-across for the anticipated ADME.
There is little difference between animals and humans in absorption, distribution, and metabolism. A difference in renal clearance is the major determinant in the differences between animals and humans, with the renal clearance in rats approximately 3 times faster than in humans.
Boric acid is not metabolised in either animals or humans, owing to the high energy level required (523 kJ/mol) to break the B - O bond (Emsley, 1989). Other inorganic borates convert to boric acid at physiological pH in the aqueous layer overlying the mucosal surfaces prior to absorption.Most of the simple inorganic borates exist predominantly as undissociated boric acid in dilute aqueous solution at physiological and environmental pH, leading to the conclusion that the main species in the plasma of mammals is un-dissociated boric acid. Since other borates dissociate to form boric acid in aqueous solutions, they too can be considered to exist as un-dissociated boric acid under the same conditions. Additional support for this derives from studies in which more than 90 % of administered doses of inorganic borates are excreted in the urine as boric acid. Absorption of borates via the oral route is nearly 100 %. For the inhalation route also 100 % absorption is assumed as worst case scenario. Dermal absorption through intact skin is very low with a percent dose absorbed of 0.226 ± 0.125 in humans. Using the % dose absorbed plus standard deviation (SD) for boric acid, a dermal absorption for borates of 0.5 % (rounded from 0.45 %) can be assumed as a worse case estimate.
In the blood boric acid is the main species present and is not further metabolised. Boric acid is distributed rapidly and evenly through the body, with concentrations in bone 2 - 3 higher than in other tissues. Boric acid is excreted rapidly, with elimination half-lives of 1 h in the mouse, 3 h in the rat and < 27.8 h in humans, and has low potential for accumulation. Boric acid is mainly excreted in the urine.
Read Across
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. As noted previously, only boric acid and the borate anion are present at environmentally and physiologically relevant concentrations. Read-across between the different boron compounds can be done on the basis of boron (B) equivalents. Conversion factors are given in the table below.
Substance | Formula | Conversion factor for equivalent dose of B (multiply by) |
Boric acid | H3BO3 | 0.1748 |
Boric Oxide | B2O3 | 0.311 |
Disodium tetraborate anhydrous | Na2B4O7 | 0.2149 |
Disodium tetraborate pentahydrate | Na2B4O7•5H2O | 0.1484 |
Disodium tetraborate decahydrate | Na2B4O7•10H2O | 0.1134 |
Disodium octaborate tetrahydrate | Na2B8O13·4H2O | 0.2096 |
Sodium metaborate (anhydrous) | NaBO2 | 0.1643 |
Sodium metaborate (dihydrate) | NaBO2·2H2O | 0.1062 |
Sodium metaborate (tetrahydrate) | NaBO2·4H2O | 0.0784 |
Sodium pentaborate (anhydrous) | NaB5O8 | 0.2636 |
Sodium pentaborate (pentahydrate) | NaB5O8∙5H2O | 0.1832 |
Calcium metaborate | Ca(BO2)2.2H2O | 0.1337 |
Calcium tetraborate | B4CaO7 | 0.2214 |
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
