4-ethoxybenzoic acid

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption

Remarks:

adsorption

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Estimated data generated using the EPI Suite model developed by the USEPA.

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

Prediction done using KOCWIN Program (v2.00)

GLP compliance:

not specified

Type of method:

other: MCI Method

Media:

soil

Specific details on test material used for the study:

- Name of test material: 4-Ethoxybenzoic acid
- Molecular formula: C9H10O3
- Molecular weight: 166.175 g/mol
- Smiles notation: c1(ccc(OCC)cc1)C(O)=O
- InChl: 1S/C9H10O3/c1-2-12-8-5-3-7(4-6-8)9(10)11/h3-6H,2H2,1H3,(H,10,11)
- Substance type: Organic
- Physical state: Solid

Radiolabelling:

not specified

Test temperature:

25 deg.C

Analytical monitoring:

not specified

Key result

Type:

Koc

Value:

19.33 L/kg

Temp.:

25 °C

Remarks on result:

other: Log Koc= 1.2862 (estimated by MCI method)

Transformation products:

not specified

KOCWIN Program (v2.00) Results:

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

SMILES : O=C(O)c(ccc(OCC)c1)c1

CHEM : Benzoic acid, 4-ethoxy-

MOL FOR: C9 H10 O3

Koc may be sensitive to pH!

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

Koc Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 5.736

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 3.5902

Fragment Correction(s):

1 Ether, aromatic (-C-O-C-) ........... : -0.6791

* Organic Acid (-CO-OH) ............... : -1.6249

Corrected Log Koc .................................. : 1.2862

Estimated Koc: 19.33 L/kg <===========

Validity criteria fulfilled:

not specified

Conclusions:

The soil adsorption coefficient i.e Koc value of 4-Ethoxybenzoic acid was estimated to be 19.33 L/kg (log Koc=1.2862) by means of MCI method (at 25 deg C). This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Executive summary:

KOCWIN model (v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical 4-Ethoxybenzoic acid (CAS No. 619 -86 -3). The soil adsorption coefficient i.e Koc value of 4-Ethoxybenzoic acid was estimated to be 19.33 L/kg (log Koc=1.2862)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Description of key information

KOCWIN model (v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical 4-Ethoxybenzoic acid (CAS No. 619 -86 -3). The soil adsorption coefficient i.e Koc value of 4-Ethoxybenzoic acid was estimated to be 19.33 L/kg (log Koc=1.2862)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:

19.33

Additional information

Various predicted data for the target compound 4-Ethoxybenzoic acid (CAS No. 619-86-3) and supporting weight of evidence study for its read across substance were reviewed for the adsorption end point which are summarized as below:

 

In a prediction done using theKOCWIN Program(v2.00) of Estimation Programs Interface (EPI Suite, 2017) the soil adsorption coefficient i.e Koc value of 4-Ethoxybenzoic acid was estimated to be 19.33 L/kg (log Koc=1.2862) by means of MCI method (at 25 deg C). This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

 

The Soil Adsorption Coefficient i.e Koc value of test substance 4-Ethoxybenzoic acid was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 540, 538, 523, 408, 128, 16.6, 2.05 and approx. 1 at pH range 0-1, 2, 3, 4, 5, 6, 7 and 8-14, respectively (log Koc value ranges from 2.7 ± 1.0 to 0)(ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017). This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

 

In an another prediction done by using ChemSpider Database (2017),the Soil Adsorption Coefficient i.e Koc value of test substance 4-Ethoxybenzoic acid (CAS no. 619 -86 -3) was estimated using ChemSpider Database. The adsorption coefficient (Koc) value of test substance 4-Ethoxybenzoic acid was estimated to be 33.08 (Log Koc = 1.519) at pH 5.5 and 1.00 (Log Koc = 0) at pH 7.4, respectively. This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

 

Additional soil adsorption coefficient i.e Koc value of test chemical4 -Ethoxybenzoic acid (CAS No. 619 -86 -3)was estimated using the SciFinder database (American Chemical Society (ACS), 2017).The soil adsorption coefficient i.e Koc value of 4-Ethoxybenzoic acid was estimated to be 417, 416, 404, 315, 99, 12.8, 1.58 and 1.0 (log Koc value ranges from 2.62 to 0) (at 25 deg C). This Koc value indicates that the substance 4-Ethoxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the adsorption coefficient i.e KOC for test substance 4-Ethoxybenzoic acid was estimated to be 59 L/kg (log Koc = 1.77).The predicted KOC result based on the 5 OECD principles. This Koc value indicates that the substance 4-Ethoxybenzoic acid has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical 4-Hydroxybenzoic acid (CAS no. 99-96-7), soil adsorption coefficient (Koc) of read across chemical 4-Hydroxybenzoic acid (CAS no. 99-96-7) was measured according to a modified version of OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method) in a podzol and alfisol soil. The properties of soil includes Podzol soil (pH = 2.8, Organic carbon (%): 4.85%, sand: silt: clay = 89.2: 8.2: 2.6%) and alfisol soil (pH = 6.7, Organic carbon (%):1.25%%, sand: silt: clay = 69.7: 14.4: 15.9%), respectively. The adsorption coefficient (Koc) value of substance 4-Hydroxybenzoic acid in a podzol and alfisol soil was estimated to be 142 (Log Koc = 2.152) and 20 (Log Koc = 1.3), respectively. Thus, based on Koc value (Koc = 20, Log Koc = 1.3) indicates that the substance 4-Hydroxybenzoic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

 

For the another read across chemical Benzoic acid, 4-hydroxy-, methyl ester (CAS no. 99-76-3), adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of read across chemical Benzoic acid, 4-hydroxy-, methyl ester (CAS no. 99-76-3). The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of substance Benzoic acid, 4-hydroxy-, methyl ester was estimated to be 87 (Log Koc = 1.939). This Koc value indicates that the substance Benzoic acid, 4-hydroxy-, methyl ester has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

On the basis of above overall results for target chemical4-Ethoxybenzoic acid(from EPI suite, ACD labs,ChemSpider, SciFinder database and CompTox Chemistry Dashboard,2017) and for its read across substance (from authoritative database HSDB, 2017), it can be concluded that the Koc value of test substance4-Ethoxybenzoic acid ranges from 1 –540indicating that the test chemical 4-Ethoxybenzoic acidhas a negligible to low sorption to soil and sediment and therefore have rapid to moderate migration potential to ground water.

[LogKoc: 1.2862]