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Physical & Chemical properties

Partition coefficient

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Administrative data

Endpoint:
partition coefficient
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The calculation was using the scientific acceptable software program as recommended in Guideline under REACH Regulation (EC) No 1907/2006.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference
Reference Type:
other: unpublished calculation
Title:
EPI Suite Results For CAS
Bibliographic source:
EPI Suite verion 4.10, online query 24.01.2013
Report date:
2013

Materials and methods

Principles of method if other than guideline:
The calculation was based on fragment method using KOWWIN (v1.68) module of software EPI Suite v.4.10
GLP compliance:
no
Partition coefficient type:
octanol-water

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylhydroquinone
EC Number:
202-443-7
EC Name:
2-methylhydroquinone
Cas Number:
95-71-6
Molecular formula:
C7H8O2
IUPAC Name:
2-methylbenzene-1,4-diol
Details on test material:
- Substance type: organic
- Physical state: solid

Results and discussion

Partition coefficient
Type:
log Pow
Partition coefficient:
1.58
Temp.:
25 °C

Any other information on results incl. tables

The substance is within the applicability domain of the model.

1) KOWWIN Program (v1.68) Results:

===============================

Log Kow(version 1.68 estimate): 1.58

Experimental Database Structure Match:

Name    : 1,4-BENZENEDIOL, 2-METHYL-

CAS Num : 000095-71-6

Exp Log P: 0.91

Exp Ref : SANGSTER (1994)

 

SMILES : Oc(c(cc(O)c1)C)c1

MOL FOR: C7 H8 O2

MOL WT : 124.14

TYPE 

 NUM

       LOGKOW FRAGMENT DESCRIPTION        

 COEFF 

 VALUE

Frag 

 1 

 -CH3   [aliphatic carbon]               

 0.5473 

 0.5473

Frag 

 6 

 Aromatic Carbon                          

 0.2940 

 1.7640

Frag 

 2 

 -OH    [hydroxy, aromatic attach]       

-0.4802 

 -0.9604

Const

    

 Equation Constant                        

        

 0.2290

Log Kow  =  1.5799

 

 

 

 

2) Assessment of estimation domain (molecular weight, fragments, correction factors):

Applicability Domain of KOWWIN v1.68

 

 

 

 

 

 

Model:

KOWWIN v1.68

CAS:

 95-71-6

SMILES:

 Oc(c(cc(O)c1)C)c1

Molecular Weight:

124.14

Molecular weight

Minimum

Maximum

Average

 

 

 

 

Training set

18.02

719.92

199.98

 

 

 

 

Validation set

27.03

991.15

258.98

 

 

 

 

Assessment of molecular weight

Molecular weight within range of training and validation set.

 

 

 

 

 

 

 

Appendix D: KOWWIN Fragments, Correction Factors, Coefficients and Frequency

 

 

 

 

 

The Tables below lists KOWWIN Fragment and Correction Factor descriptors with their coefficient values (Coef).

 

 

 

Max = maximum number of the fragment or correction factor that occurs in any individual compound

 

 

 

 

Number = the number of individual compounds having the fragment or correction factor in the dataset

 

 

 

 

The training dataset includes a total of 2447 compounds.

 

 

 

 

 

 

The validation dataset includes a total of 10946 compounds.

 

 

 

 

 

 

Part 1: Fragments

 

 

 

 

 

 

 

Fragment

Descriptor

Coef

Training Set

Validation Set

No. of instances of each fragment for the current substance

 

 

 

Max

Number

Max

Number

.

-CH3

[aliphatic carbon]

0.5473

13

1401

20

7413

1

Aromatic Carbon

 

0.294

24

1790

30

8792

6

-OH

[hydroxy, aromatic attach]

-0.4802

3

193

4

611

2

Part 2: Correction Factors

 

 

 

 

 

 

.

Correction Factor Descriptor

Coef

Training Set

Validation Set

No. of instances of each correction factor for the current substance

Max

Number

Max

Number

.

Applicant's summary and conclusion

Conclusions:
The partition coefficient of test substance was estimated to be logPow= 1.58 at 25°C