Registration Dossier

Administrative data

Endpoint:
phototransformation in water
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication which meets basic scientific principles

Data source

Reference
Reference Type:
publication
Title:
Influence of humic substances on photolysis of nitroaromatic compounds systems
Author:
Simmons MS, Zepp RG
Year:
1986
Bibliographic source:
Wat.Res.Vol. 20 No. 7,pp 899-904

Materials and methods

Study type:
direct photolysis
Principles of method if other than guideline:
see Method
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
3-nitrotoluene
EC Number:
202-728-6
EC Name:
3-nitrotoluene
Cas Number:
99-08-1
Molecular formula:
C7H7NO2
IUPAC Name:
1-methyl-3-nitrobenzene
Details on test material:
- Name of test material (as cited in study report): 3-Nitrotoluene
- Analytical purity: no data

Study design

Analytical method:
high-performance liquid chromatography
Light source:
sunlight
Light spectrum: wavelength in nm:
366
Details on light source:
A merry-go-round photoreactor (Moses et al., 1969)
equipped with a 450 W mercury lamp and Corning 0-52 and
7-37 filters to isolate the 366-nm line was used for the
monochromatic light exposures.
Dark controls:
yes
Computational methods:
Rate constant for photoreaction represents the disappearance rate constant incorporating
both corrections for variation in light intensity
during exposure as well as light attenuation effects by the
humus solutions.

Results and discussion

Quantum yield (for direct photolysis):
0.02
Predicted environmental photolytic half-life:
A half-life of 2.6 hours can be derived under the conditions of latitude 40°N in surface waters. It has to be kept in mind that this half-life cannot be transferred directly to environmental conditions because the photolytical active zone is only close to the surface of surface waters due to turbidity and absorption.

Any other information on results incl. tables

It was observed that the photodegradation in pure water is slower than in natural water. 
The photodegradation depends on the content in humic acid and nitrates, which is higher in natural water.

Applicant's summary and conclusion