Registration Dossier

Administrative data

Endpoint:
phototransformation in water
Type of information:
experimental study
Adequacy of study:
other information
Study period:
approx. 1987
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No standard test procedure, but in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference
Reference Type:
publication
Title:
Photocatalysed oxidation of toxic organics
Author:
Borup MB and Middlebrooks EJ
Year:
1987
Bibliographic source:
Water Sci. Technol. 19, 381-390

Materials and methods

Study type:
indirect photolysis
Test guideline
Qualifier:
according to
Guideline:
other: Test conditions as reported
Principles of method if other than guideline:
UV irradiation induced decomposition of hydrogen peroxide followed by reaction of the resulting OH radicals with the test substance. Relevant parameters were varied and their effect on the removal rate of isophorone was determined.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Isophorone, purity not reported. Initial concentration 62 mg/l

Study design

Radiolabelling:
no
Analytical method:
gas chromatography
Details on sampling:
Extraction of an aliquot with methylene chloride followed by phase separation
Buffers:
no
Light source:
other: Low pressure mercury vapor lamp
Light spectrum: wavelength in nm:
ca. 254
Details on light source:
intensity of UV radiation: approx. 1210 µW/cm2
Sensitiser (for indirect photolysis)
Type of sensitiser:
other: hydrogen peroxide
Concentration of sensitiser:
250 mg/L
Details on test conditions:
One control without H2O2
One control without UV irradiation
Duration of test at given test condition
Initial conc. measured:
62 mg/L
Reference substance:
no
Dark controls:
no

Results and discussion

% Degradationopen allclose all
Test condition:
Direct photolysis
% Degr.:
> 99.9
Sampling time:
60 min
Test condition:
Indirect photolysis
Transformation products:
not measured

Any other information on results incl. tables

No degradation was observed in controls with H2O2 or UV irradiation alone, respectively. The rate constant varied with intensity of UV radiation. It was first order with respect to H2O2 concentration and zero order with respect to isophorone 

concentration.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
Direct photodecomposition of the test substance was not observed at 254 nm. Indirect photodegradation was complete (> 99.9 %) within 60 minutes. The results are not relevant for environmental conditions.
Executive summary:

Direct photodecomposition of the test substance was not observed at 254 nm. Indirect photodegradation was complete (> 99.9 %) within 60 minutes. The results are not relevant for environmental conditions.