Allyl 3-cyclohexylpropionate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Remarks:

The (Q)SAR is an accepted calculation method, therefore generally being considered as reliable study with restrictions. As this approach is taken from (1) ECHA's Guidance on information requirements and chemical safety assessment - Chapter R.7a: Endpoint specific guidance, and from (2) "European Chemical Bureau Technical Guidance Document on Risk Assessment Part III", the computation method is considered a valid.

Guideline:

other: REACH guidance on QSARs R.6, May/July 2008

Principles of method if other than guideline:

The adsorption coefficient of the substance was estimated using different QSPR estimation methods.

GLP compliance:

no

Type of method:

other: QSPR estimation

Media:

other: QSPR estimation

Test temperature:

Computation referring to a temperature of 20 °C.

Computational methods:

- Adsorption coefficient per organic carbon (Koc):
The adsorption coefficient of the substance allyl 3-cyclohexylpropionate was estimated with the KOCWIN modelling program (version 2) by using the first-order Molecular Connectivity Index (MCI) and by using the octanol-water partition coefficient (log Kow). Additionally, different equations based on a correlation of the Koc and Kow values were applied (Gerstl 1990, Sabljic and Güsten 1995).

Key result

Type:

Koc

Value:

1 820

Temp.:

20 °C

Remarks on result:

other: Geometric mean of Koc values determined with five approaches

Key result

Type:

log Koc

Value:

3.26

Temp.:

20 °C

Remarks on result:

other: Geometric mean of Koc values determined with five approaches

Type:

log Koc

Value:

2.86

Temp.:

20 °C

Remarks on result:

other: PCKOCWIN MCI

Type:

log Koc

Value:

3.22

Temp.:

20 °C

Remarks on result:

other: PCKOCWIN log KOW

Type:

log Koc

Value:

3.566

Temp.:

20 °C

Remarks on result:

other: Gerstl method

Type:

log Koc

Value:

3.145

Temp.:

20 °C

Remarks on result:

other: Sabljic and Güsten (esters)

Type:

log Koc

Value:

3.563

Temp.:

20 °C

Remarks on result:

other: Sabljic and Güsten (mainly hydrophobic substances)

SMILES: O=C(OCC=C)CCC(CCCC1)C1

CHEM: Cyclohexanepropanoic acid, 2-propenyl ester

MOL FOR: C12 H20 O2

MOL WT : 196.29

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

KOC Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 6.826

Non-Corrected Log KOC (0.5213 MCI + 0.60) .......... : 4.1580

Fragment Correction(s):

1 Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -1.2970

Corrected Log KOC .................................. : 2.8611

Estimated KOC: 726.2 L/kg <===========

KOC Estimate from Log KOW:

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

Log KOW (User entered ) ......................... : 4.28

Non-Corrected Log KOC (0.55313 log KOW + 0.9251) .... : 3.2903

Fragment Correction(s):

1 Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -0.0656

Corrected Log KOC .................................. : 3.2247

Estimated KOC: 1678 L/kg <===========

Equation from Gerstl (1990): log KOC = 0.679 · og KOW + 0.663 (n = 419, r2 = 0.831)

Computation for neononyl acetate: log KOC = 0.679 · 4.276 + 0.663

The result for neononyl acetate is: log KOC = 3.566

Equation from Sabljic and Güsten (1995), ester compounds: log KOC = 0.49 · log KOW + 1.05 (n = 25, r2= 0.76)

Computation for neononyl acetate: log KOC = 0.49 · 4.276 + 1.05

The result for neononyl acetate is: log KOC = 3.145

Equation from Sabljic and Günsten (1995), mainly hydrophobic substances: log KOC = 0.81 · log KOW + 0.10 (n = 81, r2 = 0.89)

Computation for neononyl acetate: log KOC = 0.81 · 4.276 + 0.10

The result for neononyl acetate is: log KOC = 3.563

Validity criteria fulfilled:

not applicable

Conclusions:

The QSPR-estimated adsorption coefficient of the substance allyl 3-cyclohexylpropionate is Koc = 1820 L/kg (log Koc = 3.26). It is proposed to use this value further in the chemical safety assessment. Substance allyl 3-cyclohexylpropionate is to be classified as having "low mobility" in soil (acc. to McCall et al. 1981).

Executive summary:

The purpose of this study was to determine the Koc of test item allyl 3-cyclohexylpropionate by the use of non experimental methods. As no single computational model could be identified which would fit completely to this task, the Koc of allyl 3-cyclohexylpropionate eventually was being calculated from the geometric mean of the results generated by four individual QSPR approaches.

 

The adsorption coefficient of the substance was estimated with the KOCWIN program using the Molecular Connectivity Index and the octanol-water partition coefficient of the substance. Further, three equations were used for the computation of the adsorption coefficient that were derived from the regression of experimental log Koc and log Kow values (Gerstl 1990, Sabljic and Günsten 1995). The approaches gave a coherent set of five data points for the log Koc value. The geometric mean log Koc value calculated from these five data points was 3.26. It is proposed to use this value further in the chemical safety assessment.

 

 

According to the testing strategy as shown in ECHA "Guidance on information requirements and chemical safety assessment - Chapter R.7a: Endpoint specific guidance", if the QSPR result is considered as reliable, but tonnage supply is > 100 tpa, then the QSPR-derived value shall be used for CSA. This QSPR is considered reliable as it is supported from several, different QSPR models, which mostly are based on real phys.-chem. properties of the test item (i.e. robustness of the approach can be assumed).

 

Finally, based on the classification of soil mobility potential as given in McCall et al.1981, with a Koc within the range 500 - 2000 substance allyl 3-cyclohexylpropionate is to be classified as having "low mobility" in soil (McCall P.J., Laskowski D.A., Swann R.L., and Dishburger H.J., (1981), “Measurement of sorption coefficients of organic chemicals and their use, in environmental fate analysis”, in Test Protocols for Environmental Fate and Movement of Toxicants. Proceedings of AOAC Symposium, AOAC, Washington DC).

Description of key information

The log Koc value was predicted with the program KOCWIN and with three QSPR methods. The log Koc = 3.26 indicates that the substance has low mobility in soil and sediment according to the classification scheme of McCall et al. (1981).

Key value for chemical safety assessment

Koc at 20 °C:

1 819.7

Additional information

Discussion of results

As no single computational model could be identified which would fit completely to this task, the Koc of allyl 3-cyclohexylpropionate eventually was being calculated from the geometric mean of the data generated by five individual QSPR approaches.The five different ways of QSPR computations mostly were based on the experimentally derived log Kow of the test item of 4.276.

 

Method	Log KOC
PCKOCWIN MCI	2.86
PCKOCWIN log KOW	3.22
Gerstl method	3.566
Sabljic and Güsten (esters)	3.145
Sabljic and Güsten (mainly hydrophobic)	3.563
Geometric mean	3.26

 

The resulting geometric mean of log Koc = 3.26 (Koc = 1820 L/kg) is considered as valid as it is being supported by several different QSPR approaches. It is proposed to use the predicted value for the adsorption coefficient of log Koc = 3.26 in the chemical safety assessment.

The substance is considered to have "low mobility" in sediments and soil (McCall 1981).

 

Waiving of further adsorption/desorption studies

As the substance is readily biodegradable fulfilling the 10-day window, further testing of adsorption/desorption of the substance is not necessary according to Regulation (EC) No 1907/2006, Annex VIII, column 2.

[LogKoc: 3.26]