Registration Dossier

Environmental fate & pathways

Phototransformation in air

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
phototransformation in air
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
QSAR prediction:Model considered valid by OECD
Qualifier:
no guideline required
Principles of method if other than guideline:
QSAR model, EPI Suite v 4.1/Aopwin v1.92
GLP compliance:
no
Remarks:
not applicable
Estimation method (if used):
PHOTOCHEMICAL REACTION WITH OH RADICALS - assumed reaction conditions used in model:
- Concentration of OH radicals:1.5E6 per cm3
- Temperature for which rate constant was calculated: 25C
- Computer programme: AOPWIN v1.92
Light source:
sunlight
Preliminary study:
Using the AOPWIN QSAR model, the photochemical degradation rate of S-allyl O-pentyl dithiocarbonate in the atmosphere is 49.0430E-12cm3/molecule-sec, with a resultant predicted half live of 2.617 Hrs (0.218 Days (12-hr day; 1.5E6 OH/cm3))
OVERALL OH Rate Constant = 49.0430 E-12 cm3/molecule-sec
HALF-LIFE = 0.218 Days (12-hr day; 1.5E6 OH/cm3)
HALF-LIFE = 2.617 Hrs




Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1
Transformation products:
no
Results with reference substance:
OVERALL OH Rate Constant = 49.0430 E-12 cm3/molecule-sec
HALF-LIFE = 0.218 Days (12-hr day; 1.5E6 OH/cm3)
HALF-LIFE = 2.617 Hrs

Hydrogen Abstraction       =  21.0430 E-12 cm3/molecule-sec

Reaction with N, S and -OH =   1.7000 E-12 cm3/molecule-sec

Addition to Triple Bonds   =   0.0000 E-12 cm3/molecule-sec

Addition to Olefinic Bonds =  26.3000 E-12 cm3/molecule-sec

Addition to Aromatic Rings =   0.0000 E-12 cm3/molecule-sec

Addition to Fused Rings    =   0.0000 E-12 cm3/molecule-sec

OVERALL OH Rate Constant =  49.0430 E-12 cm3/molecule-sec

HALF-LIFE =     0.218 Days (12-hr day; 1.5E6 OH/cm3)

HALF-LIFE =     2.617 Hrs

Validity criteria fulfilled:
yes
Remarks:
The photochemical degradation rate of S-allyl O-pentyl dithiocarbonate in the atmosphere is 49.0430E-12cm3/molecule-sec, with a resultant predicted half live of 2.617 Hrs (0.218 Days (12-hr day; 1.5E6 OH/cm3))
Conclusions:
Using the AOPWIN QSAR model, the photochemical degradation rate of S-allyl O-pentyl dithiocarbonate in the atmosphere is 49.0430E-12cm3/molecule-sec, with a resultant predicted half live of 2.617 Hrs (0.218 Days (12-hr day; 1.5E6 OH/cm3))
Executive summary:

Using the AOPWIN QSAR model, the photochemical degradation rate of O-isopropyl ethylthiocarbamate in the atmosphere is 45.7698 E-12cm3/molecule-sec, with a resultant predicted half live of 2.804 Hrs ( 0.234 Days (12-hr day; 1.5E6 OH/cm3))

Endpoint:
phototransformation in air
Data waiving:
other justification
Justification for data waiving:
other:

Description of key information

If released to air, a vapor pressure of  0.00316mm Hg at 25 deg C (0.00316mm Hg is equivalent to vapour pressure of 0.421Pa ) indicates S-allyl O-pentyl dithiocarbonate will exist solely as a vapor in the atmosphere. Vapor-phase S-allyl O-pentyl dithiocarbonate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 0.218 days, calculated from its rate constant of 49.0430 E-12 cm3/molecule-sec at 25 deg. S-allyl O-pentyl dithiocarbonate do not contain chromophores that absorb at wavelengths >290 nm and therefore S-allyl O-pentyl dithiocarbonate is not expected to be susceptible to direct photolysis by sunlight.

 

Using the AOPWIN QSAR model, the photochemical degradation rate of S-allyl O-pentyl dithiocarbonate in the atmosphere is 49.0430E-12cm3/molecule-sec, with a resultant predicted half live of 2.617Hrs(0.218 Days (12-hr day; 1.5E6 OH/cm3))

 OVERALL OH Rate Constant = 49.0430 E-12 cm3/molecule-sec

  HALF-LIFE =    0.218 Days (12-hr day; 1.5E6 OH/cm3)

  HALF-LIFE =    2.617 Hrs

Key value for chemical safety assessment

Half-life in air:
2.617 h
Degradation rate constant with OH radicals:
0 cm³ molecule-1 s-1

Additional information