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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Transport and distribution

Adsorption / desorption

 

The log of the adsorption coefficient (KOC) of S-allyl O-pentyl dithiocarbonate was estimated to be log KOC = 2.1858 which is equal to a KOC value of 153.4 using the KOCWIN v2.00 QSARmethod. This value indicates that S-allyl O-pentyl dithiocarbonate will be adsorbed by organic carbon in soil.

S-allyl O-pentyl dithiocarbonate can be classified to be of very high mobility in soil according these results and does not have a high potential for adsorption to soil. S-allyl O-pentyl dithiocarbonate adsorbs strongly to sulphide minerals but has less affinity for surfaces in general. The KOC value of 153.4 also suggest this conclusion.

 

 

 Henry's Law constant

 

The estimated Henrys Law Constant (25 deg C) measured by calculation from EPI SuiteTM v4.1, HENRYWIN v3.20 Program was 1.425E-005 atm-m3/mole  (1.444E+000 Pa-m3/mole).

This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency).

 

Distribution modelling.

 

S-allyl O-pentyl dithiocarbonate has no affinity to be in air and sediment. The direct emissions to soil and surface water are significant, therefore S-allyl O-pentyl dithiocarbonate  will be almost exclusively be found in soil and surface water.

 

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  1.98e-010 (atm), in air (atm)   7.66e-012 and soil   1.54e-009 (atm) and sediment to be   1.66e-010 (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. 

  

Other distribution data

 

 

These results suggest for S-allyl O-pentyl dithiocarbonate that direct and indirect exposure from distribution in media is unlikely. Based on low vapor pressure and low estimated log Pow, expected to partition to water and soil. Not expected to partition to air, sediments or biota.  Therefore testing for distribution in media does not need to be performed. 

 

 The estimated STP Fugacity Model and Volatilization From Water were measured by calculation from EPI SuiteTM v4.1 Program. This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency) .        

 

 Volatilization From Water

  =========================

 

Chemical Name: Carbonic acid, dithio-, S-allyl O-pentyl ester

 

Molecular Weight   : 204.35 g/mole

Water Solubility   : -----

Vapor Pressure     : -----

Henry's Law Constant: 2.4E-005 atm-m3/mole (estimated by Bond SAR Method)

 

                            RIVER            LAKE

                          ---------        ---------

Water Depth    (meters):  1                1         

Wind Velocity   (m/sec):  5                0.5       

Current Velocity (m/sec):  1                0.05      

 

     HALF-LIFE (hours) :  36.33            516.2     

     HALF-LIFE (days ) :  1.514            21.51     

 

 

STP Fugacity Model: Predicted Fate in a Wastewater Treatment Facility

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

  (using 10000 hr Bio P,A,S)

PROPERTIES OF: Carbonic acid, dithio-, S-allyl O-pentyl ester

-------------

Molecular weight (g/mol)                            204.35

Aqueous solubility (mg/l)                             0

Vapour pressure (Pa)                                  0

               (atm)                                 0

               (mm Hg)                            0

Henry 's law constant (Atm-m3/mol)                    2.4E-005

Air-water partition coefficient                       0.000981529

Octanol-water partition coefficient (Kow)             2137.96

Log Kow                                               3.33

Biomass to water partition coefficient                428.392

Temperature [deg C]                                   25

Biodeg rate constants (h^-1),half life in biomass (h) and in 2000 mg/L MLSS (h):

         -Primary tank       0.00     4614.35      10000.00

         -Aeration tank      0.00     4614.35      10000.00

         -Settling tank      0.00     4614.35      10000.00

 

 STP Overall Chemical Mass Balance:

 ---------------------------------

                            g/h              mol/h         percent

 

Influent                   1.00E+001        4.9E-002       100.00

 

Primary sludge             4.95E-001        2.4E-003        4.95

Waste sludge               4.54E-001        2.2E-003        4.54

Primary volatilization     1.10E-002        5.4E-005        0.11

Settling volatilization    2.93E-002        1.4E-004        0.29

Aeration off gas           7.94E-002        3.9E-004        0.79

 

Primary biodegradation     3.00E-003        1.5E-005        0.03

Settling biodegradation    8.81E-004        4.3E-006        0.01

Aeration biodegradation    1.16E-002        5.7E-005        0.12

 

Final water effluent       8.92E+000        4.4E-002       89.16

 

Total removal              1.08E+000        5.3E-003       10.84

Total biodegradation       1.55E-002        7.6E-005        0.15

 

 

 

 

 

 

 

 

Additional information