Registration Dossier

Administrative data

Endpoint:
phototransformation in air
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
supporting study
Study period:
1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
accepted calculation method

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999

Materials and methods

Principles of method if other than guideline:
Method: ATKINSON calculation based on chemical structure
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Light source:
other: estimated values

Results and discussion

% Degradation
% Degr.:
50
Sampling time:
3.6 h
Degradation rate constant
Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1

Any other information on results incl. tables

Several mechanisms for degradation of chemicals bound to particles in air  or in 

gas phase are known. Following the physical and chemical properties and the 

structure of Piperonyl butoxide it is assumed that degradation and persistence of

the active substance mainly depends on reaction with hydroxyl radicals. The 

photochemical degradation of Piperonyl butoxide in air was estimated using the 

model AOPWIN (version 1.80). The constants for reaction on different adsorption 

systems and mechanisms of binding to hydroxyl radicals were estimated to be 

51.273x 10-12 cm³/molec. sec for  hydrogen abstraction and 56.3119 x 10-12 cm³/molec. 

sec for addition to aromatic rings.Half-life in the troposphere was calculated to

 be 3.579  hours for overall OH rate constant.

Rate constant (for indirect photolysis): = 0.0000000001075849 cm³/(molecule*sec)
Degradation in % (for indirect photolysis): = 50  after 3.6 hour(s)

Applicant's summary and conclusion

Conclusions:
Rate constant (for indirect photolysis): = 0.0000000001075849 cm³/(molecule*sec) Degradation in % (for indirect photolysis): = 50  after 3.6 hour(s)