Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
adsorption / desorption
Remarks:
other: in silico
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
November 2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation method using accepted and valid (Q)SAR method.
Justification for type of information:
1. SOFTWARE
EPISuite - KOCWIN

2. MODEL (incl. version number)
KOCWIN v2.00 (September 2010)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CLC(=O)c1ccc2C(=O)OC(=O)c2c1

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF

5. APPLICABILITY DOMAIN
See attached QPRF

6. ADEQUACY OF THE RESULT
See attached QPRF
Principles of method if other than guideline:
The Soil Adsorption Coefficient Program (KOCWIN) estimates the soil adsorption coefficient (Koc) of organic compounds. Koc can be defined as "the ratio of the amount of chemical adsorbed per unit weight of organic carbon (oc) in the soil or sediment to the concentration of the chemical in solution at equilibrium" (Lyman, 1990); it is represented by the following equation (Lyman, 1990):

Koc = (μg adsorbed/g organic carbon) / (μg/mL solution)

The units of Koc are typically expressed as either L/kg or mL/g.

Koc provides an indication of the extent to which a chemical partitions between solid and solution phases in soil, or between water and sediment in aquatic ecosystems. Estimated values of Koc are often used in environmental fate assessment because measurement of Koc is expensive. Traditional estimation methods rely upon the octanol/water partition coefficient or related parameters, but the first-order molecular connectivity index (MCI) has been used successfully to predict Koc values for hydrophobic organic compounds (Sabljic, 1984, 1987; Bahnick and Doucette, 1988). The original KOCWIN program (PCKOC) used MCI and a series of group contribution factors to predict Koc (Meylan et al., 1992). This group contribution method was shown to outperform traditional estimation methods based on octanol/water partition coefficients and water solubility.

Since the introduction of the original PCKOC program in 1992, the number of available experimental Koc values has grown significantly. Using an expanded experimental dataset and the original PCKOC methodology, the QSAR equations were re-regressed to derive updated coefficient values. In addition, several new group contribution factors (correction factors) were added to improve estimation accuracy. Also, the updated KOCWIN program includes a separate Koc estimate based upon Log Kow (rather than MCI).
Specific details on test material used for the study:
4-chloroformylphthalic anhydride
Type:
Koc
Value:
20.03 L/kg
Remarks on result:
other: from log Kow
Type:
log Koc
Value:
1.302 dimensionless
Remarks on result:
other: from log Kow

SMILES : CLC(=O)c1ccc2C(=O)OC(=O)c2c1

CHEM   :

MOL FOR: C9 H3 CL1 O4

MOL WT : 210.57

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

 Koc Estimate from Log Kow:

 -------------------------

        Log Kow  (Kowwin estimate)  ......................... :  1.51

        Non-Corrected Log Koc (0.55313 logKow + 0.9251)  .... :  1.7603

        Fragment Correction(s):

                 2   Misc (C=O) Group (aliphatic attach)....  : -0.4586

        Corrected Log Koc  .................................. :  1.3018

                        Estimated Koc:  20.03  L/kg   <===========

Validity criteria fulfilled:
yes
Conclusions:
The estimated value of Koc (from log Kow) is predicted to be 20.03 L/Kg. However it should be noted that the susbtance does not fall in the applicability domain of the model. Therefore this value is not reliable.
According to the McCall classification scheme and based on this value, 4-chloroformylphtalic anhydride may be highly mobile (0 < Koc < 50) on soil.
This result is given only for information, and must be taken with caution. The reliability level is not considered sufficient for a regulatory purpose.
Executive summary:

Koc was calculated using the computer program KOCWIN (v2.00).

The estimated value of Koc (from log Kow) is predicted to be 20.03 L/Kg. However it should be noted that the substance does not fall in the applicability domain of the model. Therefore this value is not reliable.

According to the McCall classification scheme and based on this value, 4-chloroformylphtalic anhydride may be highly mobile (0 < Koc < 50) on soil.

This result is given only for information, and must be taken with caution. The reliability level is not considered sufficient for a regulatory purpose.

Endpoint:
adsorption / desorption
Remarks:
other: in silico
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
November 2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation method using accepted and valid (Q)SAR method.
Justification for type of information:
1. SOFTWARE
EPISuite - KOCWIN

2. MODEL (incl. version number)
KOCWIN v2.00 (September 2010)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CLC(=O)c1ccc2C(=O)OC(=O)c2c1

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF

5. APPLICABILITY DOMAIN
See attached QPRF

6. ADEQUACY OF THE RESULT
See attached QPRF
Principles of method if other than guideline:
The Soil Adsorption Coefficient Program (KOCWIN) estimates the soil adsorption coefficient (Koc) of organic compounds. Koc can be defined as "the ratio of the amount of chemical adsorbed per unit weight of organic carbon (oc) in the soil or sediment to the concentration of the chemical in solution at equilibrium" (Lyman, 1990); it is represented by the following equation (Lyman, 1990):

Koc = (μg adsorbed/g organic carbon) / (μg/mL solution)

The units of Koc are typically expressed as either L/kg or mL/g.

Koc provides an indication of the extent to which a chemical partitions between solid and solution phases in soil, or between water and sediment in aquatic ecosystems. Estimated values of Koc are often used in environmental fate assessment because measurement of Koc is expensive. Traditional estimation methods rely upon the octanol/water partition coefficient or related parameters, but the first-order molecular connectivity index (MCI) has been used successfully to predict Koc values for hydrophobic organic compounds (Sabljic, 1984, 1987; Bahnick and Doucette, 1988). The original KOCWIN program (PCKOC) used MCI and a series of group contribution factors to predict Koc (Meylan et al., 1992). This group contribution method was shown to outperform traditional estimation methods based on octanol/water partition coefficients and water solubility.

Since the introduction of the original PCKOC program in 1992, the number of available experimental Koc values has grown significantly. Using an expanded experimental dataset and the original PCKOC methodology, the QSAR equations were re-regressed to derive updated coefficient values. In addition, several new group contribution factors (correction factors) were added to improve estimation accuracy. Also, the updated KOCWIN program includes a separate Koc estimate based upon Log Kow (rather than MCI).
Type:
Koc
Value:
10 L/kg
Type:
log Koc
Value:
0.827 dimensionless
Remarks on result:
other: from MCI

SMILES : CLC(=O)c1ccc2C(=O)OC(=O)c2c1

CHEM   :

MOL FOR: C9 H3 CL1 O4

MOL WT : 210.57

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

 Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index  ........... :  6.592

        Non-Corrected Log Koc (0.5213 MCI + 0.60)  .......... :  4.0363

        Fragment Correction(s):

                 2   Misc (C=O) Group (aliphatic attach)....  : -3.2093

        Corrected Log Koc  .................................. :  0.8270

        Over Correction Adjustment to Lower Limit Log Koc ... :  1.0000

                        Estimated Koc:  10  L/kg   <===========

Validity criteria fulfilled:
yes
Conclusions:
The estimated value of Koc (from MCI) is predicted to be 10 L/Kg.
According to the McCall classification scheme, this means that 4-chloroformylphtalic anhydride is very highly mobile (0 < Koc < 50) on soil.
The substance falls in the applicability domain of the model regarding the Molecular Weight and the Log Kow, but not regarding the structural fragment domain.
Therefore the estimated Koc of 10 L.kg is not fully reliable.
According to the McCall classification scheme and based on this value, 4-chloroformylphtalic anhydride may be highly mobile (0 < Koc < 50) on soil.
This result is given only for information, and must be taken with caution.
Executive summary:

Koc was calculated using the computer program KOCWIN (v2.00). The estimated value of Koc (from MCI) is predicted to be 10 L/Kg.

The substance falls in the applicability domain of the model regarding the Molecular Weight and the Log Kow, but not regarding the structural fragment domain.

Therefore the estimated Koc of 10 L.kg is not fully reliable. But it should be noted that overall this calculation using the MCI methodology is somewhat more accurate than the Log Kow methodology (see data in the corresponding endpoint study record in the IUCLID file).

According to the McCall classification scheme and based on this value, 4-chloroformylphtalic anhydride may be highly mobile (0 < Koc < 50) on soil.

This result is given only for information, and must be taken with caution.

This QSAR prediction is not judged to be fully adequate to meet the data requirements for Regulation (EC) 1907/2006, Annex VIII, 9.3.1., Adsorption/desorption screening.

 

Description of key information

(Q)SAR-modelled adsorption coefficient (Koc) values for trimellitic anhydride mono-chloride (TMAC) range from 10 to 20.03 L/kg.

Key value for chemical safety assessment

Koc at 20 °C:
10

Additional information

(Q)SAR-modelled adsorption coefficient (Koc) values for trimellitic anhydride mono-chloride (TMAC) obtained with the KOCWIN v2.00 model of the US EPA range from ca. 10 to 20 L/kg. Based on these values, TMAC is expected to have a low tendency to adsorb to soils and sediments.

However, it should ne noted that the substance falls in the applicability domain of the model regarding the Molecular Weight and the Log Kow, but not regarding the structural fragment domain.

Therefore the estimated Koc is not fully reliable.

This result is given only for information, and must be taken with caution.

This QSAR prediction is not judged to be fully adequate to meet the data requirements for Regulation (EC) 1907/2006, Annex VIII, 9.3.1.,Adsorption/desorption screening.

It should be noted that the water exposure is not expected. In additon the substance is readily biodegradable and hydrolyses rapidly. Therefore the estimation of the Koc value can be waived in the REACH context.