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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.

Diss Factsheets

Administrative data

dissociation constant
Type of information:
experimental study
Adequacy of study:
key study
Study period:
16/04/2018 - 04/09/2018
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report

Materials and methods

Test guideline
according to guideline
OECD Guideline 112 (Dissociation Constants in Water)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Reference substance name:
bismuth subsalicylate
bismuth subsalicylate
Test material form:
solid: particulate/powder
migrated information: powder
Details on test material:
Product name: Bismuth Subsalicylate
Specific details on test material used for the study:
Batch/Lot Number: 2018000421

Results and discussion

Dissociating properties:
not determined
Dissociation constant of the test item could not be determined under the conditions of this study.

Applicant's summary and conclusion

Dissociation constant cannot be calculated because of low solubility. As the substance does not dissolve, it cannot dissociate in water.
Executive summary:

The dissociation of a chemical in water is of importance in assessing its impact upon the environment. It governs the form of the substance which in turn determines its behaviour and transport. It may affect the adsorption of the chemical on soils and sediments and adsorption into biological cells.

According to the OECD No. 112 guideline, three methods are available for dissociation constant determination. As the test item had no light absorption properties, the spectrophotometric method could not be used. As approximately 0.1 M solution of the test item was not achievable, the conductometry method could not be used either. Therefore, the titration method was applied.

Dissociation constant of the test item could not be determined under the conditions of this study. It was considered that the low solubility of the test item prevented the titration method from being feasible (the titration method is not suitable for low solubility substances).