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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

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Diss Factsheets

Environmental fate & pathways

Phototransformation in water

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
phototransformation in water
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:

Description of key information

There are no tests on photolysis of the substance (reaction product) in aqueous solutions available which would allow deriving a reaction rate for surface waters. The main constituent MBO exhibits no chromophore and no absorption of light is observed at wavelength > 290 nm. Chemicals with UV/absorption maximum of < 290 cannot undergo direct photolysis in sunlight and according to US EPA OPPTS 835.2210 the test is not applicable for these substances. Therefore, a test for phototransformation of MBO in water is not necessary to perform.

Key value for chemical safety assessment

Additional information

For the atmosphere, indirect photolysis is expected. Therefore, indirect phototransformation in water cannot be excluded. However, in aqueous media the constituents of the reaction product are hydrolysed. Therefore, removal in surface waters is expected due to hydrolysis. In addition, biodegradation is expected. Compared with these degradation mechanisms, photolysis in surface waters is assumed to be of minor importance. In conclusion, a test on photolysis in aqueous solutions would not improve the database for the hazard assessment and thus is scientifically unjustified.