Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

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Additional information

Biodegradation in water: screening test

In a test for ready biodegradability according to OECD Guideline 301 D (Ready Biodegradability, Closed Bottle Test, activated sludge, domestic, non-adapted) 23 % of the test material degraded in 28 days.

The test material is considered not readily biodegradable by non-adapted domestic activated sludge.

Biodegradation in water and sediment: simulation test

No data on the biodegradation in sediments and surface water are available for the test item. However, further biotic degradation testing shall be proposed if the chemical safety assessment according to Annex I indicates the need to investigate further degradation of the substance and its degradation products. The test substance were found to be non-biodegradable in a study concerning ready biodegradability. It is not expected that the DT90 of the test item in an OECD 308 or 309 would indicate a rapid biodegradation in sediment and surface water e.g. < 100 d. Based on these facts the simulation tests according OECD 308 and 309 are not warranted.

Biodegradation in soil

No data on the biodegradation in soil are available for the test item (stilbene fluorescent whitening agent). However, further biotic degradation testing shall be proposed if the chemical safety assessment according to Annex I indicates the need to investigate further degradation of the substance and its degradation products. The test substances were found to be non-biodegradable in studies concerning ready biodegradability. It is assumed that the test substance is not biodegradable in simulation tests either. Therefore, simulation studies in soil are not provided for the stilbene fluorescent whitening agent.

Nevertheless a RIVM report (Plassche et al., 1999) shows that stilbene fluorescent whitening agents will be effectively degraded by photochemical processes (see also IUCLID Chapter 5.1.3). It is shown that first photoisomerization occurs, followed by photodegradation. Rates are rapid: half-lives are in order of 1 hour or even less. The US EPA property estimation program AOPWIN v 1.92 calculates a Half-Life of 6 hours (Hydroxyl Radicals reaction) and 2 hours (Ozone reaction) for a stilbene principle structure.

UV-VIS spectrum of the test item showed an absorption band with a maximum located at 350 nm. Therefore direct photo degradation is very likely.