trans-1,4-bis(isocyanatomethyl)cyclohexane

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

N/A

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:

In accordance with section 2 of REACH Annex XI, as the substance reacts with water, it is technically not feasible to perform the study Partition coefficient n-octanol/water (section 7.8). In accordance with column 2 of REACH Annex VII, the Partition coefficient n-octanol/water has been calculated.

Qualifier:

no guideline followed

Principles of method if other than guideline:

KOWWIN (the Log Octanol-Water Partition Coefficient Program) estimates the logarithmic octanol-water partition coefficient (log P) of organic compounds. KOWWIN requires only a chemical structure to estimate a log P. Structures are entered into KOWWIN by SMILES (Simplified Molecular Input Line Entry System) notations.

The KOWWIN program and estimation methodology were developed at Syracuse Research Corporation.

KOWWIN uses a "fragment constant" methodology to predict log P. In a "fragment constant" method, a structure is divided into fragments (atom or larger functional groups) and coefficient values of each fragment or group are summed together to yield the log P estimate. KOWWIN’s methodology is known as an Atom/Fragment Contribution (AFC) method. Coefficients for individual fragments and groups were derived by multiple regression of 2447 reliably measured log P values. KOWWIN’s "reductionist" fragment constant methodology (i.e. derivation via multiple regression) differs from the "constructionist" fragment constant methodology of Hansch and Leo (1979) that is available in the CLOGP Program (Daylight, 1995). See the Meylan and Howard (1995) journal article for a more complete description of KOWWIN’s methodology.

The KOWWIN training and validation datasets can be downloaded from the Internet at:
http://esc.syrres.com/interkow/KowwinData.htm

References:
Hansch, C and Leo, A.J. 1979. Substituent Constants for Correlation Analysis in Chemistry and Biology; Wiley: New York, 1979.
Daylight. 1995. CLOGP Program. Daylight Chemical Information Systems. Von Karman Ave., Irvine, CA 92715. (web-site as of March 2008: http://www.daylight.com/)
Meylan, W.M. and P.H. Howard. 1995. Atom/fragment contribution method for estimating octanol-water partition coefficients. J. Pharm. Sci. 84: 83-92.

GLP compliance:

no

Type of method:

other: QSAR

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

3.92

Temp.:

25 °C

pH:

ca. 7

Remarks on result:

other: Calculated value

Log Octanol-Air Partition Coefficient (25 deg C) [KOAWIN v1.10]:

Log Kow used: 3.92 (KowWin est)

Log Kaw used: -2.817 (HenryWin est)

Log Koa (KOAWIN v1.10 estimate): 6.737

Log Koa (experimental database): None

 

Conclusions:

By using the estimation program KOWWIN (version 1.68), the log Kow of 1,4-H6XDI is calculated to be 3.92.

Reference 2

Endpoint:

partition coefficient

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with section 2 of REACH Annex XI, as the substance reacts with water, it is technically not feasible to perform the study Partition coefficient n-octanol/water (section 7.8). In accordance with column 2 of REACH Annex VII, the Partition coefficient n-octanol/water has been calculated.

Description of key information

The log Kow of the substance was calculated to be 3.92 at 25°C (KOWWIN Program (v1.68)).

Key value for chemical safety assessment

Log Kow (Log Pow):

3.92

at the temperature of:

25 °C

Additional information

As the substance reacts with water, it is technically not feasible to determine the log Kow experimentally. In accordance with column 2 of REACH Annex VII, the partition coefficient n-octanol/water has therefore been calculated.