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EC number: 432-690-8
CAS number: -
No significant hydrolysis was detected at pH values of 4, 7 ,and 9 at 50
°C after 5 days. The half life at ambient temperature was estimated to
be greater than 1 year.
Phototransformation in water
In dilute solutions and
in presence of sunlight,stilbene
fluorescent whitening agentsundergo reversible
isomerization of the stilbene moiety. In this process, two isomeric
forms occur. The E- and Z-isomers are under environmental conditions in
equilibrium within a few minutes. The parent substances used as
fluorescent whitening agent consist of the E-isomer, while isomerization
to the Z-form leads to complete loss of fluorescence. Two studies
demonstrate that at solar latitude 60°, at 25°C, and on surface layer
depths of 0 to 5m the remaining E-isomer fraction is 13.9 to 9.5 and
17.8 to 13.3, respectively. The preceding isomer equilibrium influences
the photo-degradation rate. The half-life for photo-oxidation in natural
water (Lake Greifensee) was measured for the same substances and under
the same light conditions on the surface layer: 278 min and 313 min. The
experimental kinetic data are used to calculate photochemical half-lives
as a function of surface layer depth, optical density of the water, and
time of the year.
on measured kinetic parameters and the quatum yield, photochemical
half-lives in three Swiss lakes are calculated according to GCSOLAR as a
function of surface layer depth and time of the year (Kramer, 1996).
Both substances degrade with nearly identical half-lives. Therefore, it
is assumed that all substances of the category follow the same
photolytical processes and areeffectively
degraded in surface waters.
RIVM report (Plassche et al., 1999) shows that stilbene fluorescent
whitening agents will be effectively degraded by photochemical processes. 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.
spectrum of the test item showed an absorption band with a maximum
located at 350 nm. Therefore direct photo degradation is very likely.
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
Based on the high molecular weight and the excellent solubility in water
a significant potential of bioaccumulation is not anticipated. Due to
the fact that the partitioning coefficient octanol water is negative a
bioconcentration and bioaccumulation is not expected.
Adsorption / desorption
In a study on adsorption/desorption in soil according to OECD Guideline
106 (Adsorption - Desorption Using a Batch Equilibrium Method) the
adsorption coefficient Koc was determined as 5580 (log Koc: 3.75). The
results of the adsorption/desorption study indicate that the test
material is tightly bound to soil components, if exposure should occur.
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.
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