Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
11-Dec-2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Structurally, CAS# 756-12-7 contains moieties that have fragment cofficients and structure corrections which are utilized by the software (KOWWIN) to calculate the log Kow. Thus, it is within the model applicability domain and is reliable.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference
Reference Type:
other: company data : QSAR Simulation Report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: REACH guidance on QSARs, R.6, May/July 2008
Deviations:
no
Principles of method if other than guideline:
KOWWIN v1.68 as implemented through EPI Suite v4.10
GLP compliance:
no
Type of method:
other: QSAR
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
CAS No. 756-12-7

Results and discussion

Partition coefficient
Key result
Type:
log Pow
Partition coefficient:
1.82
Remarks on result:
other: QSAR method, Temp and pH not applicable

Any other information on results incl. tables

Validity of Model (OECD 5 principles):

1) Defined endpoint: Partition coefficient

2) Unambiguous algorithm: The predicted value of the log Kow is calculated through the following equation:

log Kow =∑f(j)n(j) + c(j)n(j) + 0.229

where f(j) is the coefficient for each atom/fragment), c(j) is the coefficient for each correction factor, and n(i) is the number of times the atom/fragment (and correction factor) occurs in the test species.

3) Applicability domain: the software's training set contains a number of fluorinated aliphatic ketones which are structurally related to the test substance, and the test substance is therefore within the applicability domain of this QSAR model.

4) Statistical characterization: Statistical variation of 6 pairs of experimental and predicted log Kows for 6 representative analogous substances indicate that there is a 0.993 correlation coefficient (r-squared), a standard deviation of 0.108 and an absolute mean error of 0.115. The estimated and experimental data for structural analogs in the training set are in good agreement and CAS# 756-12-7 is within the applicability domain of the model.

5) Mechanistic interpretation: In aquatic systems chemicals may partition to lipid rich tissue of aquatic organisms. Octanol is considered a reasonable analog for the lipid-rich tissues of aquatic organisms. The octanol water partition coefficient is representative of a chemicals tendency to partition to the lipid-rich tissues or remain in the aqueous phase. The log Kow is a basis by which to assess a chemicals potential for bioconcentration (via lipid-rich tissue partitioning).

Please see attached QMRF and QPRF for justification of model and applicability.

Applicant's summary and conclusion

Conclusions:
CAS#756-12-7 has an estimated log Kow of 1.82 using KOWWIN v1.68 as implemented through EPI Suite v4.10.
Executive summary:

The partition coefficient n-octanol/water of CAS# 756-12-7 was determined using the KOWWIN v1.68 QSAR as implemented through EPI Suite v4.10. CAS#756-12-7 is reactive with water and therefore estimation is the most reliable method of log Kow determination. The validity of this QSAR to predict log Kow for these types of substance was determined to be reliable based on the statistics (0.993 correlation coefficient (r-squared), a standard deviation of 0.108 and an absolute mean error of 0.115) derived from a comparison of experimental and estimated log Kow values for 6 representative analogous fluorinated aliphatic ketones. The agreement between predicted and calculated values indicates that this modeled is accurate for this type of substance. This study is classified as an acceptable QSAR and satisfies the requirements for partition coefficient study. It is pertinent to the fate of CAS# 756-12-7 and may be used for risk analysis, classification and labelling, and PBT analysis.

The estimated log Kow of 1.82 indicates that CAS# 756-12-7 is not anticipated to bioconcentrate by partitioning to the lipid rich tissues of aquatic organisms.