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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 939-592-9 | CAS number: 67254-71-1
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Data waiving:
- study scientifically not necessary / other information available
- Justification for data waiving:
- the study does not need to be conducted because the substance has no ionic structure
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- supporting study
- Study period:
- 02 Feb 2012
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- guideline study with acceptable restrictions
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 112 (Dissociation Constants in Water)
- Deviations:
- yes
- Remarks:
- test concentration was too high, test solution contained undissolved test item
- GLP compliance:
- no
- Remarks on result:
- other: The conductivity caused from dissociated test item was too low to carry out the measurements of the dilution series necessary for calculation.
Referenceopen allclose all
Verification of the method with benzoic acid:
Ka (benzoic acid): 6.493 x 10 -5 mol/L
pKa (benzoic acid), calculated: 4.19
pKa (benzoic acid), theoretical: 4.12
System check (20 °C):
Orion 5 star |
Value |
KCl solution 0.01 mol/L, certified (1413 μS/cm) |
1380-1440 μS/cm |
KCl solution 0.01 mol/L, measurement |
1418 μS/cm |
Sample measurement (20 °C), Alcohols, C10 -12, Ethoxylated (EO<2.5):
Sample measurement |
Concentration [g/L] |
Conductivity [μS/cm] |
Demineralised water |
- |
0.8 |
Sample solution 1 |
5.075 |
11.1 |
Sample solution 2 |
4.023 |
9.2 |
Results:
The conductivity caused from dissociated test item was too low to carry out the measurements of the dilution series necessary for calculation. Due to this fact the calculation of the dissociation contant was not possible. The study was aborted.
Description of key information
The substance has no ionic structure
Key value for chemical safety assessment
Additional information
Attempts were made to experimentally determine possible dissociation constants of the substance according to OECD Guideline 112. However, due to very low conductivity, the conductometric method proved not sensitive enough to obtain reliable results. Therefore the test was aborted.
The test result is supported by theory, because based on evaluation of the chemical structure of the substance, dissociation within the pH range -0.2 to 14 is not expected.
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.
