Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

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 Sodium Isopropyl Xanthate (SIPX) in the atmosphere is 12.1686 E-12 cm3/molecule-sec, with a resultant predicted half live of 10.548 Hrs ( 0.879 Days (12-hr day; 1.5E6 OH/cm3))
OVERALL OH Rate Constant = 12.1686 E-12 cm3/molecule-sec
HALF-LIFE = 0.879 Days (12-hr day; 1.5E6 OH/cm3)
HALF-LIFE = 10.548 Hrs
Reaction with:
OH radicals
Rate constant:
0 cm³ molecule-1 s-1
Transformation products:
no
Results with reference substance:
OVERALL OH Rate Constant = 12.1686 E-12 cm3/molecule-sec
HALF-LIFE = 0.879 Days (12-hr day; 1.5E6 OH/cm3)
HALF-LIFE = 10.548 Hrs

Hydrogen Abstraction      = 12.1686 E-12 cm3/molecule-sec

Reaction with N, S and -OH =  0.0000 E-12 cm3/molecule-sec

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

Addition to Olefinic Bonds =  0.0000 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 = 12.1686 E-12 cm3/molecule-sec

HALF-LIFE = 0.879 Days (12-hr day; 1.5E6 OH/cm3)

HALF-LIFE = 10.548 Hrs

Validity criteria fulfilled:
yes
Remarks:
The photochemical degradation rate of Sodium Isopropyl Xanthate (SIPX) in the atmosphere is 12.1686 E-12 cm3/molecule-sec, with a resultant predicted half live of 10.548 Hrs ( 0.879 Days (12-hr day; 1.5E6 OH/cm3))
Conclusions:
Using the AOPWIN QSAR model, the photochemical degradation rate of Sodium Isopropyl Xanthate (SIPX) in the atmosphere is 12.1686 E-12 cm3/molecule-sec, with a resultant predicted half live of 10.548 Hrs ( 0.879 Days (12-hr day; 1.5E6 OH/cm3))
Executive summary:

Using the AOPWIN QSAR model, the photochemical degradation rate of Sodium Isopropyl Xanthate (SIPX) in the atmosphere is 12.1686 E-12 cm3/molecule-sec, with a resultant predicted half live of 10.548 Hrs ( 0.879 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

Using the AOPWIN QSAR model, the photochemical degradation rate of Sodium Isopropyl Xanthate (SIPX) in the atmosphere is 12.1686 E-12 cm3/molecule-sec, with a resultant predicted half live of 10.548    Hrs ( 0.879 Days (12-hr day; 1.5E6 OH/cm3))
If released to air, a vapor pressure of 0.00000000288 mm Hg at 25 deg C (0.00000000288 mm Hg is equivalent to vapour pressure of 3.84E-007 Pa ) indicates that Sodium Isopropyl Xanthate (SIPX) will exist solely as a vapor in the atmosphere. Vapor-phase Sodium Isopropyl Xanthate (SIPX) 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 0.879 days, calculated from its rate constant of 12.1686 E-12 cm3/molecule-sec at 25 deg.
Xanthates do not contain chromophores that absorb at wavelengths >290 nm and therefore Sodium Isopropyl Xanthate (SIPX) is not expected to be susceptible to direct photolysis by sunlight.

Key value for chemical safety assessment

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

Additional information

Using the AOPWIN QSAR model, the photochemical degradation rate of Sodium Isopropyl Xanthate (SIPX) in the atmosphere is 12.1686 E-12 cm3/molecule-sec, with a resultant predicted half live of 10.548 Hrs ( 0.879 Days (12-hr day; 1.5E6 OH/cm3)).

 

OVERALL OH Rate Constant = 12.1686 E-12 cm3/molecule-sec

HALF-LIFE = 0.879 Days (12-hr day; 1.5E6 OH/cm3)

HALF-LIFE = 10.548 Hrs

If released to air, a vapor pressure of 0.00000000288mm Hg at 25 deg C (0.00000000288mm Hg is equivalent to vapour pressure of 3.84E-007 Pa ) indicates thatSodium Isopropyl Xanthate (SIPX) will exist solely as a vapor in the atmosphere. Vapor-phase Sodium Isopropyl Xanthate (SIPX) 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 0.879 days, calculated from its rate constant of 12.1686 E-12 cm3/molecule-sec at 25 deg.

Xanthates do not contain chromophores that absorb at wavelengths >290 nm and thereforeSodium Isopropyl Xanthate (SIPX) is not expected to be susceptible to direct photolysis by sunlight.