Registration Dossier

Administrative data

Endpoint:
distribution modelling
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
not applicable
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: US EPA accepted QSAR method for organic chemicals properties assessment. Recognised method of fugacity calculations.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference
Reference Type:
other: QSAR
Title:
EPI Suite v 4.1/Level III Fugacity Model
Author:
US EPA
Year:
2011
Bibliographic source:
http://epa.gov/oppt/exposure/pubs/episuite.htm

Materials and methods

Model:
calculation according to Mackay, Level III
Calculation programme:
EPI Suite v 4.1/Level III Fugacity Model
Release year:
2 011
Media:
other: all

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: compact
Details on test material:
SMILES : O(C(CC)C)C(S)=S
CHEM : Carbonodithioic acid, o-(2-methylpropyl) ester, sodium salt
MOL FOR: C5 H10 O1 S2

Study design

Test substance input data:
- Parameters as per physicochemical summary data.
- Reaction half-life estimates for:
- Air: 16 hr (from AOPWIN)
- Water: 360 hr (Based on Biowin)
- Soil: 720 hr
- Sediment: 3240 hr

Assumed emissions: Four simulations as per results below
Environmental properties:
- Environmental compartment sizes and character as per the TGD

Results and discussion

Percent distribution in media

Air (%):
0
Water (%):
29.7
Soil (%):
70.2
Sediment (%):
0.069
Susp. sediment (%):
0
Biota (%):
0
Aerosol (%):
0
Other distribution results:
The figures above represent the first emission scenario shown below

Any other information on results incl. tables

 

   

Level III Fugacity Model (Full-Output):

=======================================

Chem Name : Carbonodithioic acid, o-(2-methylpropyl) ester, sodium salt

Molecular Wt: 172.24

Henry's LC : 3.49e-016 atm-m3/mole (calc VP/Wsol)

Vapor Press : 1.26e-009 mm Hg (Mpbpwin program)

Liquid VP : 7.19e-008 mm Hg (super-cooled)

Melting Pt : 203 deg C (Mpbpwin program)

Log Kow : -1.33 (Kowwin program)

Soil Koc : 11.7 (KOCWIN MCI method)

 

TABLE 1

 

Mass Amount

(percent)

Half-Life

(hr)

Emissions

 

(kg/hr)

Air

9.95e-008

16

1000

 

Water

29.7

360

1000

 

Soil

70.2

720

1000

 

Sediment

0.069

3.24e+003

0

 

TABLE 2A

 

Fugacity

atm)

Reaction

(kg/hr)

Advection

(kg/hr)

Reaction

(percent)

Advection

(percent)

Air

2.03e-019

8.36e-005

1.93e-005

2.79e-006

6.44e-007

Water    

5.84e-021

1.11e+003

577

37

19.2

 

Soil

2.64e-019

1.31e+003

0

43.8

0

Sediment

5.3e-021

0.287

0.0268

0.00955

0.000893

 

 

Persistence Time: 647 hr

Reaction Time: 801 hr

Advection Time: 3.37e+003 hr

Percent Reacted: 80.8

Percent Advected: 19.2

 

Half-Lives (hr), (based upon Biowin (Ultimate) and Aopwin):

Air: 16.01

Water: 360

Soil: 720

Sediment: 3240

Biowin estimate: 2.819 (weeks )

Advection Times (hr):

Air: 100

Water: 1000

Sediment: 5e+004

 

Applicant's summary and conclusion

Conclusions:
Sodium isobutyl xanthate has no affinity to be in air and sediment. The direct emissions to soil and surface water are significant, therefore Sodium isobutyl xanthate will be almost exclusively be found in soil and surface water.
Executive summary:

Mackay fugacity modelling (level 3) indicates that, taking into account degradation and using inflow parameters which are consistent with the known production tonnage of this substance in, fugacity coefficient indicates that environmental concentrations in water are predicted to be 5.84e-021 (atm), in air (atm) 2.03e-019and soil 2.64e-019 (atm) and sediment to be  5.3e-021  (atm).

These are negligible low levels. This can be considered a worse case prediction as it assumes all product is emitted with no emission control systems used.