Registration Dossier

Administrative data

Endpoint:
Henry's law constant
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Scientifically acceptable method

Data source

Referenceopen allclose all

Reference Type:
other: EPIWIN calculation
Title:
Unnamed
Year:
2018
Report Date:
2018
Reference Type:
other: Estimation software
Title:
Estimation Programs Interface Suite for Microsoft Windows, v4.11
Author:
US EPA
Year:
2012
Bibliographic source:
United States Environmental Protection Agency, Washington, DC, USA

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation of Henry's Law Constant. Software used: SRC HENRYWIN v3.20: Bond estimation method
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Henry's Law constant H
H:
0 Pa m³/mol
Temp.:
25 °C
Remarks on result:
other: The substance is within the applicability domain of the model.

Applicant's summary and conclusion

Executive summary:

QPRF: HENRYWIN v3.20: Bond contribution method

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

Degree of volatilisation of substances from the aquatic environment

Dependent variable

Henry’s Law Constant

3.2

Algorithm
(OECD Principle 2)

Model or submodel name

HENRYWIN: Bond contribution method

Model version

v. 3.20

Reference to QMRF

Henry’s Law constant (HLC) using HENRYWIN v3.2: Estimation Accuracy (QMRF)

Predicted value (model result)

See “Results and discussion: Henry’s Law constant H”

Input for prediction

Chemical structure via CAS number or SMILES

Descriptor values

- Bond contribution values

- Correction factors

3.3

Applicability domain
(OECD principle 3)

Domains:

1) Molecular weight (range of test data set: 26.04 to 451.47 g/mol, mean: 144.64 g/mol) (On-Line HENRYWIN User’s Guide, Ch. 7.4 Estimation Domain and Appendix G)

Substance(not) within range (XX g/mol)

2) Maximum number of instances of bond in any of the training set compounds (On-Line HENRYWIN User’s Guide, Appendix D)

(Not)exceeded

3) Maximum number of instances of correction factor in any of the training set compounds (On-Line HENRYWIN User’s Guide, Appendix E)

(Not)exceeded

3.4

The uncertainty of the prediction
(OECD principle 4)

According to REACH Guidance Document R.7a, Appendix R.7.1-1 (Nov. 2012), measurement of HLC is not highly accurate, especially for very high or very low HLC values. The bond contribution method regarded by Altschuh et al. (1999) to produce the most reliable results with the exception of organochlorine pesticides. However, for some compounds, the method can yield a Henry's Law constant of 1.0x10-12atm*m3/mol or smaller. Numbers which are smaller than this value may be unrealistically low.

3.5

The chemical mechanisms according to the model underpinning the predicted result
(OECD principle 5)

The compound is split into a summation of individual bonds which comprise the compound. The summation of these bonds (= bond contribution values) is set equal to LWPAC. Correction factors were developed to correct for polar interactions and other deviations from the regression curve, which are applied to members of some chemical classes.

 

References:

Altschuh, J.R., Bruggemann, H. Santl, G. Eichinger, and O.G. Piringer.1999. Henry’s law constants for a diverse set of organic chemicals: experimental determination and comparison of estimation methods. Chemosphere 39: 1871-87.

On-Line HENRYWINUser's Guide:

-      Appendix D: Bond Method Contribution Values used by HENRYWIN.

-      Appendix E: Bond Method Correction Factors Used by HENRYWIN.

-      Appendix G. Chemicals Used to Derive Bond Contribution Values & Correction Factors.

Identified number of bonds and correction factors for the current substance:

HLC Appendix D, Table D-1: Bond Contribution Values Derived by Least-Square Regression Analysis

Bond

Coefficient
Value

No. Compounds
 in Training Set
containing
the Bond

Maximum No.
of instances of
each Bond
occurring in any
single compound

Comment

No. of instances
of each bond
found for the
current substance

C-H

-0.119677

284

27

Hydrogen bond

22

O-H

3.23177

42

3

Hydrogen bond

1

C-C

0.116304

200

9

 

7

C-N

1.300997

20

3

 

3

C-O

1.085473

83

4

 

1

HLC Appendix D, Table D-2: Bond Contribution Values from a Subsequent Regression

Not applicable

HLC Appendix D, Table D-3: Additional Bond Contribution Values Used HENRYWIN

Not applicable

HLC Appendix E, Table E-1: Bond Correction Factors Derived from the Original Regression

Not applicable

HLC Appendix E, Table E-2: Bond Correction Factors Derived from the Second Regression

Not applicable

HLC Appendix E, Table E-3: Bond Correction Factors Derived Individually

Not applicable