Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Several studies on the biodegradability in water are available on the substance and its analogues (CAS 16324-27-9, CAS 4193-55-9 and CAS 16470-24-9) within the Stilbene Fluorescent Whitening Agents category (see Justification Category Report in section 13 of the technical dossier).

 

For all members of the category no biodegradation was observed, neither readily, neither inherently. It can be noted that whitin the whole category the adsorption recorded in the Zahn Wellens tests is different. In substances less soluble, as CAS 16090-02-1 (1.9 g/l) or CAS 4193.3-55-9 (48.2 g/l), the adsorption recorded was extent: 83-89 % after first 3 hrs in the case of CAS 16090-02-1; 66.8 % after 3 hrs and 83.6 % after 24 hrs for CAS 4193-55-9.

The degree and timing of adsorption recorded in this type of test method decrease for substances with higher water solubility: 15.9 % after 3 hrs and 37.1 % after 24 hrs in case of CAS 16324-27-9, with a water solubility of 104.4 g/l; 18.7 % after 3 hrs and 9.2 % after 24 hrs in the case of CAS 41098-56-0, with water solubility of 201.1 g/l; 0.7-12 % after 3 hrs and ca 15 % after 24 hrs for CAS 16470-24-9, with a water solubility of 650 g/l.

Anaerobic degradation can happen, but it is not a main degradation pathway and results seam in disagreements.

A field study at a full-scale STP on the analogous substance CAS 16090-02-1 (Poiger 1994) gave no evidence of biodegradation when the mass flow was monitored.

It can be assumed that the substance under registration would be non biodegradable in soil and sediment either.