Registration Dossier

Diss Factsheets

Environmental fate & pathways

Phototransformation in soil

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The substance degrades rapidly under illumination conditions simulating natural sunlight.

Key value for chemical safety assessment

Half-life in soil:
18 d

Additional information

The rate of photolysis and degradation pattern was determined with 14C- labelled substance. In illuminated soil samples, extractable radioactivity (99.2-100.8 % at day 0) steadily decreased to 73.4-74.1 % at day 30. Consequently, non-extractable radioactivity increased from 0.1% at day 1 to 10.9 % at day 30, indicating that complete mineralization occurred. For the dark controls, radioactivity could be completely extracted for all time intervals.


During illumination, the parent substance decreased from 93.3% at day 0 to 27.1% at day 30. Besides the parent compound, two fractions were found in significant amounts at day 30 of illumination: 4-aldehyde-4’-(2-sulfostyryl)biphenyl (16.1%) , unidentified substance (15.2%). Amongst the minor amounts (1.8-3.0%) 4,4’-bisaldehyde biphenyl was identified. During incubation in the dark, almost exclusively the parent substance was found, ranging from 90.8 to 83.4%.


Degradation on soil under illumination conditions simulating natural sunlight (light/dark cycle: 12 hours) proceed with a half-life of 18.0 days.