Registration Dossier

Administrative data

Endpoint:
phototransformation in water
Type of information:
other: BUA report
Adequacy of study:
other information
Reliability:
other: BUA report
Rationale for reliability incl. deficiencies:
other: BUA report

Data source

Referenceopen allclose all

Reference Type:
other: BUA report
Title:
Unnamed
Year:
1990
Reference Type:
publication
Title:
Ein Beitrag zur Photostabilität organischer Umweltchemikalien in Gegenwart von Wasserstoffperoxid in aquatischen Systemen [in German]
Author:
Mansour M, Moza PN, Barlas H, Parlar H
Year:
1985
Bibliographic source:
Chemosphere 14, 1469-1474
Reference Type:
publication
Title:
Photoinduzierte Hydroxylierungsreaktionen organischer Chemikalien in natürlichen Gewässern - Nitrate als potentielle OH-Radikalquellen- [in German]
Author:
Russi H, Kotzias D, Korte F
Year:
1982
Bibliographic source:
Chemosphere 11: 1041-1048
Reference Type:
publication
Title:
Photochemischer Abbau von chlorierten aromatischen Verbindungen durch Sauerstoffspezies in aquatischen Systemen [in German]
Author:
Mansour M, Hustert K, Moza PN, Kettrup A
Year:
1989
Bibliographic source:
VDI Berichte Nr. 745: 927-936

Materials and methods

Principles of method if other than guideline:
BUA report
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
1,2-dichlorobenzene
EC Number:
202-425-9
EC Name:
1,2-dichlorobenzene
Cas Number:
95-50-1
Molecular formula:
C6H4Cl2
IUPAC Name:
1,2-dichlorobenzene

Results and discussion

Any other information on results incl. tables

BUA report:

Three publications on the phototransformation of 1,2 -dichlorobenzene in water were summarized in the assessment of the BUA report 53 (1990). The reliability of these publications was not assignable because references were only cited as secondary literature.

The photochemical oxidative degradation of o-dichlorobenzene in water was investigated in the presence of hydrogen peroxide on irradiation with light of wavelength > 290 nm and yielded an OH radical reaction rate constant of 3.00 x 10^9 L/(mol*s). Given an estimated OH radical concentration in natural waters of 10^-16 to 10^-17 mol/L, this translates to a half-life of 642 - 6418 hours of sunshine. One cause of the formation of OH radicals in natural waters is photolysis of nitrate ions. Furthermore, a mean OH radical concentration of 5 x 10^-16 mol/L was quoted in water that was sampled at a depth of 8 cm beneath the surface of the river Goldach, a tributary of the Isar in Munich, 440 m above sea level, under cloudless skies in April. This translates to a half-life of 12.8 days, given 10 hours of sunshine per day.

According to the third publication, degradation proceeds via intermediates (chlorobenzene, chlorophenol) as far as mineralization to CO2 and HCl.

Applicant's summary and conclusion

Conclusions:
The photochemical oxidative degradation of o-dichlorobenzene in water was investigated in the presence of hydrogen peroxide on irradiation with light of wavelength > 290 nm and yielded an OH radical reaction rate constant of 3.00 x 10^9 L/(mol*s). Given an estimated OH radical concentration in natural waters of 10^-16 to 10^-17 mol/L, this translates to a half-life of 642 - 6418 hours of sunshine.
Executive summary:

Three publications on the phototransformation of 1,2 -dichlorobenzene in water were summarized in the assessment of the BUA report 53 (1990). The reliability of these publications was not assignable because references were only cited as secondary literature.

The photochemical oxidative degradation of o-dichlorobenzene in water was investigated in the presence of hydrogen peroxide on irradiation with light of wavelength > 290 nm and yielded an OH radical reaction rate constant of 3.00 x 10^9 L/(mol*s). Given an estimated OH radical concentration in natural waters of 10^-16 to 10^-17 mol/L, this translates to a half-life of 642 - 6418 hours of sunshine. One cause of the formation of OH radicals in natural waters is photolysis of nitrate ions. Furthermore, a mean OH radical concentration of 5 x 10^-16 mol/L was quoted in water that was sampled at a depth of 8 cm beneath the surface of the river Goldach, a tributary of the Isar in Munich, 440 m above sea level, under cloudless skies in April. This translates to a half-life of 12.8 days, given 10 hours of sunshine per day.

According to the third publication, degradation proceeds via intermediates (chlorobenzene, chlorophenol) as far as mineralization to CO2 and HCl.