Gum of Cistus ladaniferus (Cistaceae) obtained from stems and leaves by extraction with alkaline solution

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

The substance is a dark brown solid. Water solubility and partition coefficient were not possible to perform. Koc study (OECD 121) is a HPLC study such as Water solubility and partition coefficient studies. As it was not possible to perform water solubility and partition coefficient studies, it is not possible to perform OECD 121 study.

Reference 2

Endpoint:

adsorption / desorption

Remarks:

adsorption

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2017-12-12 to 2017-12-12

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Use of valid QSARs

Justification for type of information:

QSAR predictions. See QMRF and QPRf in the "attached backgound material" section.
ECHA Guidance (chapter R.7.a,paragraph R.7.1.15) recommends calculating the Koc as the geometric mean of results obtained by means of QSARs.

Qualifier:

according to guideline

Guideline:

other: Reach guidance on QSAR - R.6

Deviations:

no

Principles of method if other than guideline:

Key value estimated by the geometric mean of 3 different QSARs as follows:
- Koc calculated by Molecular Connectivity Index (MCI) using KOCWIN v2.00 from EPISUITE 4.1 software
- Koc calculated from log kow using KOCWIN v2.00 from EPISUITE 4.1 software
- Koc calculated from Log Kow according to TGD 2003.

GLP compliance:

no

Remarks:

Calculated results

Type of method:

other: QSAR

Media:

soil

Specific details on test material used for the study:

SMILES : O=C(O)CCc(cccc1)c1

Radiolabelling:

no

Computational methods:

- Calculations by Molecular Connectivity Index (MCI) using the CAS number as input
- Calculations using log kow of 1.84 as input (value taken from experimental DB, proposed by default by the model KOCWIN v2.00).
- Calculations from Log Kow according to equations defined by Sabljic and Güsten (1995) for non hydrophobic substances as reported in the
TGD, 2003: logKoc = 0.52 logKow + 1.02. A log kow = 1.84 has been used, value taken from the experimental DB of the QSAR model KOCWIN v 2.00

Key result

Type:

Koc

Value:

42.39 L/kg

Remarks on result:

other: Geometric mean of the 3 QSARs

Type:

Koc

Value:

53.88 L/kg

Remarks on result:

other: MCI method from KOCWIN v2.00

Type:

Koc

Value:

14.91 L/kg

Remarks on result:

other: Log kow method from KOCWIN v 2.00

Type:

Koc

Value:

94.8 L/kg

Remarks on result:

other: According to TGD 2003 (equations defined by Sabljic and Güsten (1995) for non hydrophobic substances)

Transformation products:

no

None

Validity criteria fulfilled:

yes

Conclusions:

The substance exhibits a Koc of 42.39 L/kg, estimated by the use of QSAR Methods corresponding to a log Koc of 1.63

Executive summary:

There are no experimental value for adsorption/desorption of the constituent 3-phenylpropanoic acid. Estimated values have been generated by QSAR Methods. The calculation methods and Koc values are reported here below:

Estimation of Log Koc by TGD (2003) Equation for non hydrophobic: Log Koc = 1.98, Koc = 94.8 L/kg

MCl Method from KOCWIN v2.00: Log Koc = 1.73, Koc = 53.88 L/kg

Log Kow Method from KOCWIN v2.00 (Input log Kow = 1.84): Log Koc = 1.17, Koc = 14.91 L/kg

 

ECHA Guidance (chapter R.7.a,paragraph R.7.1.15) recommends calculating the Koc endpoint value of a compound as the geometric mean of results obtained by means of QSARs.

Geometric mean of Koc = 42.39 L/kg

This gives a Log Koc = 1.63

Description of key information

An experimental study on the NCS itself to determine the adsorption was technically not feasible due to the complex nature of the substance.

Only one constituent of the NCS is known (3 -phenylpropanoic acid). For information, this constituent exhibits a Koc of 42.39 L/kg, estimated by the use of 3 different QSAR Methods, corresponding to a log Koc of 1.63.

Because of the concentration ranges of this constituent in the NCS (between 0.01 and 3% w/w according to the SIP), this value cannot be considered representative of the NCS itself.