Registration Dossier
Registration Dossier
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EC number: 932-833-9 | CAS number: -
Dissociation constant
Administrative data
Link to relevant study record(s)
Description of key information
Dissociation constant: Ammonia (9.25), citric acid (3.13, 4.76, 6.4)
Key value for chemical safety assessment
Additional information
The substance is expected to dissociate to citrate, iron and ammonia in the environment. For the purposes of exposure estimation and risk characterisation, iron, ammonia and citrate are considered separately.
Dissociation constant is not relevant for iron. Citric acid/citrate has three ionisable carboxylic acid groups. pKa values of 3.13, 4.76 and 6.4 at 25°C were reported in handbooks which have been subject to peer-review and in which the original data are traceable. Similarly, ammonia has a reported pKa of 9.25 at 25°C in a handbook of reliable data. The results are considered to be reliable. In secondary sources to which reliability could not be assigned, pKa values of 2.79, 4.3, 5.65 and 3.13, 4.76, 6.4 and 14.4 were reported for citric acid.
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.
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