Trifluoro(trifluoromethoxy)ethylene

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:

the study does not need to be conducted because the substance has a low octanol water partition coefficient and the adsorption potential of this substance is related to this parameter

the study does not need to be conducted because the physicochemical properties of the substance indicate that it can be expected to have a low potential for adsorption

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
According to Annex XI section 2 testing for a specific endpoint may be omitted if it is technically not possible to conduct the study as a consequence of the properties of the substance.
PMVE is a gas at ambient conditions. The gaseous nature of the substance makes the experimental determination not technically feasible, in fact it would be practically impossible to appropriately test PMVE and provide meaningful results according to the standard methods.

In order to evaluate the soil adsorption potential of PMVE, Quantitative Structure Activity Relationships (QSARs)assessments have been applied.
The estimated Kow (KOWWIN model v1.67a, EPISUITE v4.00) and Koc value of PMVE (KOCWIN model v.2.0, EPI Suite v 4.0) indicate that the potential for PMVE adsorption to soil and sediment is low:
Log Kow = 1.42
Koc = 96.38 L/Kg (estimated from MCI) corresponding to log Koc = 1.98
Koc = 41.68 L/Kg (estimated from log Kow) corresponding to log Koc = 1.62
This further supports the fact that the experimental determination is unnecessary. In fact, according to Column 2 of REACH Annexes VIII and IX ‘The study does not need to be conducted if based on the physicochemical properties the substance can be expected to have a low potential for adsorption".

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

supporting study

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:

Well known QSAR prediction software. Well documented and published methodology. The compound appears to fall within the applicability domain of the model.

Justification for type of information:

QMRF and QPRF are attached

Guideline:

other: REACH guidance on QSARs R.6

Principles of method if other than guideline:

QSAR for the prediction of LogKoc, based on LogKow with fragment based corrections for polar molecules. The methodology is published in Doucette, W.J. Soil and sediment sorption coefficients, in Handbook of Property Estimation Methods, Environmental and Health Sciences, Boethling, R.S., Mackay, D. (Eds.), Boca Raton, Lewis Publishers. The QSAR model has been updated with more data in the training set since the original publication.

GLP compliance:

no

Type of method:

other: log Kow based mode

Media:

other: not applicable

Specific details on test material used for the study:

SMILE: FC(F)(F)OC(F)=C(F)F

Radiolabelling:

no

Test temperature:

Not specified

Details on study design: HPLC method:

not applicable

Analytical monitoring:

not required

Details on sampling:

not applicable

Details on matrix:

not applicable

Details on test conditions:

not applicable

Type:

Koc

Value:

41.68 L/kg

Type:

log Koc

Value:

1.62 dimensionless

Descriptor domain: The substance's molecular weight (MW=166.02g/mol) falls within the range of molecular weights of compounds in the training set: 32-665g/mol, average 224g/mol. The estimated LogK_ow(1.42) falls within the range of values for the compounds in the training set

Reference 3

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

supporting study

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:

Well known QSAR prediction software. Well documented and published methodology. The compound appears to fall within the applicability domain of the model.

Justification for type of information:

QMRF and QPRF are attached

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

QSAR for the prediction of LogKoc, based on molecular connectivity index with fragment based corrections for polar molecules. The original methodology is published in Meylan, W. et al, Environ. Sci. Technol., 1992, 26, 1560-1567. The QSAR model has been updated with more data in the training set since the original publication.

GLP compliance:

no

Type of method:

other: molecular connectivity index based model

Media:

other: not applicable

Specific details on test material used for the study:

SMILE: FC(F)(F)OC(F)=C(F)F

Radiolabelling:

no

Test temperature:

not specified

Details on study design: HPLC method:

not applicable

Analytical monitoring:

not required

Details on sampling:

not applicable

Details on matrix:

not applicable

Details on test conditions:

not applicable

Type:

Koc

Value:

96.38 L/kg

Type:

log Koc

Value:

1.98 dimensionless

Descriptor domain: The substance's molecular weight (MW=166.02 g/mol) falls within the range of molecular weights of compounds in the training set: 32-665 g/mol, average 224 g/mol. The MCI descriptor value (4.327) lies within the range of the training set molecules: 1-16.6

Validity criteria fulfilled:

not applicable

Description of key information

PMVE is a gas at ambient conditions.

The gaseous nature of the substance makes the experimental determination not technically feasible, in fact it would be practically impossible to appropriately test PMVE and provide meaningful results according to the standard methods.

Being the experimental determination unfeasible, in order to evaluate the soil adsorption potential of PMVE a Quantitative Structure Activity Relationships (QSARs) assessment has been applied. The estimated Koc value of PMVE (KOCWIN model ,v.2.0, EPI Suite v 4.0) is Koc = 96.38 L/Kg (estimatedfrom MCI) and Koc = 41.68 L/Kg (estimated from log Kow) indicating that the potential for PMVE adsorption to soil and sediment is low. This further supports the fact that the substance is expected to rapidly distribute to the atmosphere without any significant adsorption to soil and sediment.

The calculated average value Koc = 69.03 is set as key value for risk assessment purpose. [corresponding to LogKoc  = 1.84]

Key value for chemical safety assessment

Koc at 20 °C:

69.03