Sodium 2-hydroxypropane-2-sulphonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically accepted calculation method

Principles of method if other than guideline:

Estimation of log Kow using KOWWIN v1.68

GLP compliance:

no

Type of method:

other: estimation method

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

-4.42

Temp.:

25 °C

Remarks on result:

other: The substance is within the applicability domain of the model.

Copy & paste table on log Kow fragment description from KOWWIN output.

Executive summary:

 

QPRF: KOWWIN v1.68 (01 Nov. 2013)

 

1.	Substance	See “Test material identity”
2.	General information
2.1	Date of QPRF	See “Data Source (Reference)”
2.2	QPRF author and contact details	See “Data Source (Reference)”
3.	Prediction
3.1	Endpoint (OECD Principle 1)	Endpoint	Octanol-water partition coefficient (log Kow)
		Dependent variable	Octanol-water partition coefficient (log Kow)
3.2	Algorithm (OECD Principle 2)	Model or submodel name	KOWWIN
		Model version	v. 1.68
		Reference to QMRF	QMRF: Estimation of Octanol-Water Partition Coefficient using KOWWIN v1.68 (EPI Suite v4.11)
		Predicted value (model result)	See “Results and discussion”
		Input for prediction	Chemical structure via CAS number or SMILES
		Descriptor values	- Chemical structure - Fragments - Correction factors
3.3	Applicability domain (OECD principle 3)	Domains:
		1) Molecular weight (range of test data set: 18.02 to 719.92 g/mol; On-Line KOWWIN User’s Guide, Ch. 6.2.3 Estimation Domain)	Substance (not) within range (162.14 g/mol)
		2) Fragments: Number of instances of the identified fragments does not exceed the maximum number as listed in Appendix D (On-Line KOWWIN User’s Guide)	fulfilled.
		3) Fragments: Substance has a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient was developed (Appendix D, On-Line KOWWIN User’s Guide)	applicable.
		4) Correction factors: Number of instances of the identified correction factor does not exceed the maximum number as listed in Appendix D (On-Line KOWWIN User’s Guide)	fulfilled.
3.4	The uncertainty of the prediction (OECD principle 4)	According to REACH Guidance Document R.7a, (Nov. 2012), solubility in water is difficult to model accurately. For this reason, as well as the fact that the experimental error on solubility measurements can be quite high (generally reckoned to be about 0.5 log unit), the prediction of aqueous solubility is not as accurate as is the prediction of octanol/water partitioning.
3.5	The chemical mechanisms according to the model underpinning the predicted result (OECD principle 5)	The water solubility of a substance depends on its affinity for water as well as its affinity for its own crystal structure. In general, substances with high melting points have poor solubility in any solvent.

 

References

- US EPA (2012). On-Line KOWWIN User’s Guide.

 

 

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

Log Kow(version 1.68 estimate): -4.42

SMILES : CC(C)(O)S(=O)(=O)O([Na])
CHEM : sodium 2-hydroxypropane-2-sulphonate
MOL FOR: C3 H7 O4 S1 Na1
MOL WT : 162.14

Type	Num	LogKow Fragment description	Coeff	Value
Frag	2	-CH3    [aliphatic carbon]	0.5473	1.0946
Frag	1	C     [aliphatic carbon - No H, not tert]	0.9723	0.9723
Frag	1	-OH     [hydroxy, aliphatic attach]	-1.4086	-1.4086
Frag	1	-SO2-O [sulfonate, aliph att]	-0.725	-0.725
Factor	1	S-O-{Na,K,Li}   [coef*(1+0.3*(NUM-1))]	-4.58	-4.58
Const	1	Equation Constant		0.229
				Log Kow   =  -4.4177

Description of key information

The logKow was determined through QSAR using EpiSuite and the KOWWIN model. The determined logKow is -4.45.

Key value for chemical safety assessment

Log Kow (Log Pow):

-4.42

at the temperature of:

25 °C