Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Transport and distribution

Adsorption / desorption

 

According to “ANNEX IX- STANDARD INFORMATION REQUIREMENTS FOR SUBSTANCES MANUFACTURED OR IMPORTED IN QUANTITIES OF 100 TONNES OR MORE , an adsorption study need not be conducted if:

— based on the physicochemical properties the substance can be expected to have a low potential for adsorption (e.g. the substance has a low octanol water partition coefficient), or

— the substance and its degradation products decompose rapidly.

The log of the adsorption coefficient (KOC) of Isopropyl Ethyl Thionocarbamate (IPETC ) was estimated to be log KOC = 1.8988which is equal to a KOC value of 79.22 using theKOCWIN v2.00 QSARmethod.

This value indicates that Isopropyl Ethyl Thionocarbamate (IPETC ) will be adsorbed by organic carbon in soil.Isopropyl Ethyl Thionocarbamate (IPETC ) can be classified to be of very high mobility in soilaccording these resultsand does not have a high potential for adsorption to soil. Isopropyl Ethyl Thionocarbamate (IPETC )adsorbs strongly to sulphide minerals but has less affinity for surfaces in general. The KOC value of 79.22 also suggest this conclusion.

 

The estimated Soil Adsorption Coefficient was 79.22 L/kg measured by calculation from EPI SuiteTM v4.1 Program. This is Exposure Assessment Tools and Models made from EPA (Environmental Protection Agency

KOCWIN Program (v2.00) Results:

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

SMILES : O(C(=NCC)S)C(C)C

CHEM : Carbamothioic acid, ethyl-, O-(1-methylethyl) ester

MOL FOR: C6 H13 N1 O1 S1

MOL WT : 147.24

--------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 4.164

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 2.7704

Fragment Correction(s):

1 Ether, aliphatic (-C-O-C-) .......... : -0.8716

Corrected Log Koc .................................. : 1.8988

Estimated Koc: 79.22 L/kg <===========

Koc Estimate from Log Kow:

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

Log Kow (Kowwin estimate) ......................... : 3.32

Non-Corrected Log Koc (0.55313 logKow + 0.9251) .... : 2.7615

Fragment Correction(s):

1 Ether, aliphatic (-C-O-C-) .......... : -0.0906

Corrected Log Koc .................................. : 2.6709

Estimated Koc: 468.7 L/kg <===========

 

 

  

 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 4.71E-006 atm-m3/mole (4.78E-001 Pa-m3/mole) , which is almost zero.

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

 

Distribution modelling.

 

Isopropyl Ethyl Thionocarbamate (IPETC ) has no affinity to be in air and sediment. The direct emissions to soil and surface water are significant, therefore Isopropyl Ethyl Thionocarbamate (IPETC ) 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 5.95e-011 (atm), in air (atm)  1.29e-011and soil  7.32e-010 (atm) and sediment to be  5.18e-011 (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 Isopropyl Ethyl Thionocarbamate (IPETC) 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: Carbamothioic acid, ethyl-, O-(1-methylethyl) ester

 

Molecular Weight   : 147.24 g/mole

Water Solubility   : -----

Vapor Pressure     : -----

Henry's Law Constant: 4.71E-006 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) :         152.1            1761      

     HALF-LIFE (days ) :         6.336            73.36     

 

 

STP Fugacity Model: Predicted Fate in a Wastewater Treatment Facility

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

  (using 10000 hr Bio P,A,S)

PROPERTIES OF: Carbamothioic acid, ethyl-, O-(1-methylethyl) ester

 

Molecular weight (g/mol)                              147.24

Aqueous solubility (mg/l)                               0

Vapour pressure (Pa)                                    0

               (atm)                                              0

               (mm Hg)                                        0

Henry 's law constant (Atm-m3/mol)             4.71E-006

Air-water partition coefficient                       0.000192625

Octanol-water partition coefficient (Kow)             2089.3

Log Kow                                                             3.32

Biomass to water partition coefficient                418.659

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     4557.29      10000.00

         -Aeration tank      0.00     4557.29      10000.00                     

         -Settling tank        0.00     4557.29      10000.00

 

                             STP Overall Chemical Mass Balance:

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

                                        g/h              mol/h         percent

 

Influent                        1.00E+001        6.8E-002       100.00

 

Primary sludge             4.85E-001        3.3E-003        4.85

Waste sludge                4.52E-001        3.1E-003        4.52

Primary volatilization    2.32E-003        1.6E-005        0.02

Settling volatilization    6.27E-003        4.3E-005        0.06

Aeration off gas           1.58E-002        1.1E-004        0.16

 

Primary biodegradation    2.97E-003        2.0E-005        0.03

Settling biodegradation     8.82E-004        6.0E-006        0.01

Aeration biodegradation   1.16E-002        7.9E-005        0.12

 

Final water effluent          9.02E+000        6.1E-002       90.23

 

Total removal                   9.77E-001        6.6E-003        9.77

Total biodegradation        1.55E-002        1.1E-004        0.15