1,1,1,3,3,3-hexafluoro-2-methoxypropane

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

19 May 2019

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

Justification for type of information:

1. SOFTWARE : US EPA BioWin v4.10

2. MODEL (incl. version number) : The following models are run in US EPA BioWIn v4.10
- Biowin1 (Linear Model Prediction) :
- Biowin2 (Non-Linear Model Prediction):
- Biowin3 (Ultimate Biodegradation Timeframe):
- Biowin4 (Primary Biodegradation Timeframe):
- Biowin5 (MITI Linear Model Prediction) :
- Biowin6 (MITI Non-Linear Model Prediction):
- Biowin7 (Anaerobic Model Prediction):

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL : COC(C(F)(F)F)C(F)(F)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The validity of the models have been well document and described in detail in the Help menue of the software and in the following publications:

Arnot, J.A., Mackay, D., Gouin, T. 2005. Development and Application of Models of Chemical Fate in Canada: Practical methods for environmental biodegradation rate estimation. Report to Environment Canada. CEMN Report No. 200503. Trent University
Boethling, R.S., Sabljic, A. 1989. Screening-level model for aerobic biodegradability based on a survey of expert knowledge. Environ. Sci. Technol. 23:672-9.
Boethling, R.S., Howard, P.H., Meylan, W., Stiteler, W., Beaumann, J., Tirado, N. 1994. Group contribution method for predicting probability and rate of aerobic biodegradation. Environ. Sci. Technol. 28:459-65.
Howard, P.H., Hueber, A.E., Boethling, R.S. 1987. Biodegradation data evaluation for structure/biodegradability relations. Environ. Toxicol. Chem. 6:1-10.
Howard, P.H., Boethling, R.S., Stiteler, W.M., Meylan, W.M., Hueber, A.E., Beauman, J.A., Larosche, M.E. 1992. Predictive model for aerobic biodegradability developed from a file of evaluated biodegradation data. Environ. Toxicol. Chem. 11:593-603.
Howard, P.H. and M. Neal.  1992.  Dictionary of Chemical Names and Synonyms.  Lewis Publishers, Chelsea, MI (ISBN 0-87371-396-6)
Jaworska, J.S., Boethling, R.S., Howard, P.H.. 2003. Recent developments in broadly applicable structure-biodegradability relationships. Environ. Toxicol. Chem. 22:1710-1723.
Tunkel, J., Howard, P.H., Boethling, R.S., Stiteler,W., Loonen, H. 2000. Predicting Ready Biodegradability in the Japanese Ministry of International Trade and Industry Test. Environ. Toxicol. Chem. 19:2478-2485.

5. Applicability of Domain: There is no universally accepted definition of the model domain but the model is reported to be most reliable when the target substance falls within the molecular weight range of the training set and/or that have more instances of a given fragment than the maximum for all training set compounds. In that regard, the target substance, with a molecular weight of 182.07 and C, CH, CH3, O, and F fragments, falls well within the training set having a molecular weight range of 16 - 943 and a large number of compounds with like frangments. In addition, the software developer states that "The current applicability of the MPBPWIN methodology is best described by its accuracy in predicting vapor pressure..." This accuracy, as applicable to the use of the software in this instance, is described above.

6. ADEQUACY OF THE RESULT: The result of "not readily biodegradable" is as would be expected for a substance of this type.

Qualifier:

no guideline required

Principles of method if other than guideline:

QSAR model using EPA BioWin v4.10

GLP compliance:

no

Specific details on test material used for the study:

SMILES : COC(C(F)(F)F)C(F)(F)F
CHEM : 1,1,1,3,3,3-Hexafluoro-2-methoxypropane
MOL FOR: C4 H4 F6 O1
MOL WT : 182.07

Oxygen conditions:

aerobic

Inoculum or test system:

other: QSAR Model based on training set comprised of various inoculum

Details on inoculum:

QSAR Model based on training set comprised of various inoculum

Key result

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Details on results:

Biowin1 (Linear Model Prediction) : Does Not Biodegrade Fast
Biowin2 (Non-Linear Model Prediction): Does Not Biodegrade Fast
Biowin3 (Ultimate Biodegradation Timeframe): Months
Biowin4 (Primary Biodegradation Timeframe): Weeks
Biowin5 (MITI Linear Model Prediction) : Not Readily Degradable
Biowin6 (MITI Non-Linear Model Prediction): Not Readily Degradable
Biowin7 (Anaerobic Model Prediction): Does Not Biodegrade Fast
Ready Biodegradability Prediction: NO

Criteria for the YES or NO prediction:  If the Biowin3 (ultimate survey model) result is "weeks" or faster (i.e. "days", "days to weeks", or "weeks" AND the Biowin5 (MITI linear model) probability is >= 0.5, then the prediction is YES (readily biodegradable).  If this condition is not satisfied, the prediction is NO (not readily biodegradable).  This method is based on application of Bayesian analysis to ready biodegradation data (see Help).  Biowin5 and 6 also predict ready biodegradability, but for degradation in the OECD301C test only; using data from the Chemicals Evaluation and Research Institute Japan (CERIJ) database.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The substance is predicted to not be readily biodegradable.

Executive summary:

An assessment of the ready biodegradability of the substance using US EPA BioWin v4.10 software concludes that the substance is not readily biodegradable. This prediction is as would be expected based on ready biodegradability testing of similar compounds.

Description of key information

An assessment of the ready biodegradability of the substance using US EPA BioWin v4.10 software concludes that the substance is not readily biodegradable. This prediction is as would be expected based on ready biodegradability testing of similar compounds.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater