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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 241-883-4 | CAS number: 17958-73-5
Biodegradation in water: screening tests
Administrative data
Link to relevant study record(s)
Description of key information
Under test conditions no biodegradation observed
Key value for chemical safety assessment
- Biodegradation in water:
- under test conditions no biodegradation observed
Additional information
No ready biodegradation test results are available on the substance under registration CAS 17958-73-5, but according to the estimation modelling BIOWIN v.4.10, the substance is predicted as non biodegradable. All substances of the Stilbene Fluorescent Whitening Agents category are predicted as non readily biodegradable and for many members of the category both readily and inherently biodegradability tests were performed, confirming the provisions (see the Category Justification Report attached to the section 13).
Studies performed on three analogues of the CAS 17958-73-5 are here reported in a weight of evidence approach: CAS 16324-27-9, the analogous hydroxyethylamino derivative tetrasulphonated sodium salt (same alkyl derivative functional group , higher solubility), CAS 4193-55-9, the analogous dihydroxyethylamino derivative disulphonated sodium salt (same sulphonation level, di-substitution with hydroxyethyl, same metabolic and degradation pathway) and CAS 16470-24-9, the analogue dihydroxyethylamino derivative tetrasulphonated.
CAS 16324-27-9: a Zahn Wellens study was performed to measure the adsorption; the study was not terminated and the adsorption at 24 hours was reported as 37.1 %. Several screening available studies (BOD/COD. Various, 2014) confirm that the substance is not rapidly biodegradable and can be assumed as non readily biodegradable.
CAS 4193-55-9: the biodegradation was assessed for the substance with a Zahn Wellens test (Novartis Services AG., 1997), where the substance adsorbed to the sludge from 67 to 84 % in 24 h and no biodegradation was observed. As a consequence the substance can be considered a non readily biodegradable. The conclusion is confirmed by a number of studies with low reliability, summarised in a report (Various, 2014a) and by the provisional calculations, based on the chemical structure.
CAS 16470-24-9: in a ready biodegradability, test according to OECD guideline 301A (Ciba-Geigy Ltd., 1992), a DOC removal of 1.2 % was observed. Hence, the substance CAS 16470-24-9 is considered not readily biodegradable. Three BOD5 tests, in which no oxygen consumption was measured, confirm that the substance results non rapid biodegradable. Additional information are given from two Zahn Wellens tests, performed according to the OECD 302B. One of them indicates a biodegradation of 24 % after 28 days (Ciba-Geigy Ltd., 1992): this value is obtained at about the fifth day, afterwards the degradation process seems to stop. The slope of the 28 days curve, the second test of inherent biodegradation (Novartis Services AG., 1997) and the BOD5/COD results reported suggest that the 24 % of DOC removal recorded in the first Zahn Wellens test can still be related to a slow adsorption process more than a biological degradation.
In conclusion, the substance can be considered as neither readily nor inherently biodegradable.
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.
