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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 233-059-8 | CAS number: 10026-12-7
Water solubility
Administrative data
Link to relevant study record(s)
Description of key information
Niobium pentachloride can be considered moderately soluble under conditions relevant for the exposure assessment.
Key value for chemical safety assessment
- Water solubility:
- 248.9 mg/L
- at the temperature of:
- 20 °C
Additional information
As reported in the CRC Handbook of Chemistry and Physics (2011-2012), niobium pentachloride decomposes after contact with water.
This data is further supported by study results available from Klink (2015) and Hedrich (2015). In pre-tests available from a hydrolysis study it could be demonstrated that niobium pentachloride decomposes upon contact with water. Addition of niobium pentachloride leads to strong temperature rise and a strong shift in pH value (<1).
The concentration of dissolved niobium at the solubility limit upon mixing NbCl5 with water at nominal loading rates of 9.1-14.0 g/L varied between 1.3 -2.3 g Nb/L (theoretically 3.74-6.79 g NbCl5/L), corresponding to an average recovery of 43.6 ± 4.3% (relative to loading).
The recovery of dissolved niobium in buffered solutions relative to the applied loading was determined in triplicate each. The following table represents the nominal loading rates of the test item resp. niobium, as well as the determined concentrations of dissolved niobium with its corresponding average recovery.
|
pH 4 Citrate Buffer |
pH 7 Phosphate Buffer |
pH 9 Borate Buffer |
Loading NbCl5[g/L] |
6.4-7.7 |
5.6-10.3 |
6.0-9.4 |
Loading Nb [g/L] |
2.2-2.6 |
1.9-3.6 |
2.1-3.2 |
Conc. of dissolved Nb [g/L] |
1.99-2.39 |
0.02-0.05 |
< 0.001 |
Average recovery ± SD [%] |
90.6 ± 0.3 |
1.5 ± 1.2 |
0.02 ± 0.02 |
The Nb-concentrations in water after pH-adjustment to equivalent pH-values differ considerably from those in buffer. The following table represents the nominal loading rates of the test item resp. niobium, as well as the determined concentrations of dissolved niobium with its corresponding average recovery.
|
pH 4 |
pH 7 |
pH 9 |
Loading NbCl5[g/L] |
11.5 |
11.5 |
14.0 |
Loading Nb [g/L] |
4.0 |
4.0 |
4.8 |
Conc. of dissolved Nb [g/L] |
< 1.1 ∙ 10-3– 4.5 ∙ 10-3 |
< 1.1 ∙ 10-3– 92.2 ∙ 10-3 |
< 1.1 ∙ 10-3– 4.1 ∙ 10-3 |
Average recovery ± SD [%] |
< 0.1 |
1.2 ± 1.2 |
< 0.1 |
The results considered most relevant for exposure assessment are those measured from NbCl5 dissolution in water with subsequent pH adjustment as also potential release of the substance to the environment will take place via process waste water which is neutralized prior to entering any sewage treatment plant.
The results from triplicate measurements in water after adjustment to pH 7 range between <1.1 mg Nb/L (LOQ; < 3.2 mg NbCl5/L) and 92.2 mg Nb/L (248.9 mg NbCl5/L).
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.
