Registration Dossier

Administrative data

Endpoint:
phototransformation in air
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline draft (Photochemical Oxidative Degradation in the Atmosphere)
Deviations:
no
Qualifier:
according to
Guideline:
other: U.S. EPA Determination of Rates of Reaction in the GAS Phase in the Troposphere §796.3900 (1992)
Deviations:
no
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
Purity: Not reported

Study design

Light source:
sunlight

Results and discussion

Dissipation half-life of parent compound
Key result
DT50:
14.046 h
Test condition:
Half-life of test substance for reaction with average daily air concentrations of hydroxyl radicals (12-hr day; 1.5E6 OH radicals per cm³)
Degradation rate constant
Key result
Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1
Transformation products:
no

Applicant's summary and conclusion

Conclusions:
Overall OH rate constant: 9.1380 x 10-12 cm3/molecule-sec
Half–life (for reaction with average daily air concentrations of hydroxyl radicals (12-hr day; 1.5 x 106 OH radicals per cm3)): 14.046 hours
Executive summary:

An estimation of the photochemical degradation (indirect phototransformation) of the test substance was calculated in accordance the requirements of the European Union Commission 91/414/EEC Annex IIA, Point 2.10 as amended by Directive 94/37/EC, 22 July 1994 and OECD Test Guideline on Photochemical Oxidative Degradation in the Atmosphere.

The calculation of the second-order rate constant and associated half-life for the reaction of the test substance in the gas phase in the troposphere, using the method of Atkinson is provided. This calculation is an estimate of the photochemical oxidative degradation (indirect phototransformation) of the test substance. The overall OH rate constant is 9.1380 x 10-12 cm3/molecule-sec. The half–life of the test substance for reaction with average daily air concentrations of hydroxyl radicals (12-hr day; 1.5 x 10E6 OH radicals per cm3) is 14.046 hours. Hydrogen abstraction, reaction with N, S and –OH and addition to aromatic rings are predicted to contribute to the rate of photochemical degradation.