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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 433-180-8 | CAS number: -
Dissociation constant
Administrative data
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1999-12-14 to 1999-12-20
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP study according to OECD guideline
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 000
- Report date:
- 2000
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 112 (Dissociation Constants in Water)
- Deviations:
- no
- GLP compliance:
- yes
Test material
- Details on test material:
- -Name of test material (as cited in study report): Reaktiv-Orange DYPR934
Constituent 1
Results and discussion
Dissociation constant
- No.:
- #1
- pKa:
- 3.1
- Temp.:
- 22 °C
- Remarks on result:
- other: pKa for alkaline range not determined because not recognized as a real one
Any other information on results incl. tables
pKa at room temperature (ca. 22°C) = 3.1 for the acid range using six mean values of three experiments.
pKa for alkaline range not determined because not recognized as a real one.
Individual Results:
The wavelength 253 nm and 480 nm were chosen for the acid as well as for the alkaline range quantification. During pH measurement the temperature was determined as follows:
Experiment I:
20.8 to 22.0 °C
Experiment II:
22.5 to 23.7 °C
Experiment III:
21.9 to 23.1 °C
The pH data were not corrected with acidity functions.
Applicant's summary and conclusion
- Conclusions:
- pKa at room temperature (ca. 22 °C) = 3.1 for the acid range using six mean values of three experiments.
pKa for alkaline range not determined because not recognized as a real one. - Executive summary:
The determination of the pKa in the acid and alkaline range was carried out according to the OECD guideline 112.
The dissociation constant of the test substance at room temperature (ca. 22 °C) was determined within the study as pka = 3.1 for the acid range, using the six mean values of three experiments.
The pka value for the alkaline range was not determined because it was not recognized as a real one. The investigations for the hydrolysis show the decomposition of the test substance in alkaline solutions. The abiotic hydrolysis data of all reactive-dyes, determined in our testing facility, resulted in a half-life period period at pH 9 and 25 °C or less than one day.
The quoted guideline demands pure or commercial grade substances for carrying out the described methods. The test substance has a purity of about 56 %. So it was not possible to calculate the possible effects of impurity on the results.
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.
