Osalmid

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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:

1. SOFTWARE:
The Estimation Programs Interface (EPI) SuiteTM

2. MODEL (incl. version number)
MPBPWIN v1.43 (September 2010)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL:
Oc1c(C(=O)Nc2ccc(O)cc2)cccc1
CAS no. 526-18-1

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: Vapour pressure

- Unambiguous algorithm: MPBPWIN estimates vapor pressure (VP) by three separate methods: (1) the Antoine method, (2) the modified Grain method, and (3) the Mackay method.  All three use the normal boiling point to estimate VP.  Unless the user enters a boiling point on the data entry screen,  MPBPWIN uses the estimated boiling point from the adapted Stein and Brown method as described in the Boiling Point section of this help file.  When a boiling point is entered on the data entry screen, MPBPWIN uses it.
 For liquids and gases, the suggested VP is the average of the Antoine and the modified Grain estimates.  
Substructure searchable data set of vapour pressure test is available at: http://esc.syrres.com/interkow/EpiSuiteData_ISIS_SDF.htm

- Appropriate measures of goodness-of-fit and robustness and predictivity: r^2 = 0.949; std deviation =0.59; avg deviation= 0.32
- Mechanistic interpretation: estimated value

5. APPLICABILITY DOMAIN
- Descriptor domain:
Currently there is no universally accepted definition of model domain.  However, users may wish to consider the possibility that property estimates are less accurate for compounds outside the Molecular Weight range of the training set compounds, and/or that have more instances of a given fragment than the maximum for all training set compounds.  It is also possible that a compound may have a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient was developed.  These points should be taken into consideration when interpreting model results.
The complete training sets for MPBPWIN's estimation methodology are not available.  Therefore, describing a precise estimation domain for this methodology is not possible.

6. ADEQUACY OF THE RESULT
The estimation is considered acceptable. The accuracy of MPBPWIN's "suggested" VP estimate was tested on a dataset of 3037 compounds with known, experimental VP values between 15 and 30 deg C (the vast majority at 25 or 20 deg C).  The experimental values were taken from the PHYSPROP Database that is part of the EPI Suite.  For this test, the CAS numbers were run through MPBPWIN as a standard batch-mode run (using the default VP estimation temperature of 25 deg C) and the batch estimates were compared to PHYSPROP's experimental VP.
 Average absolute error = 15.5 deg Kelvin
 Standard deviation = 24.6 deg Kelvin
 Average error = 3.2%

It was then validated on a dataset of 6584 compounds collected from HODOC (1990) (compounds not used in the training set) with the following statistical accuracy (Stein and Brown, 1994):
 Average absolute error = 20.4 deg Kelvin
 Standard deviation = 38.1 deg Kelvin
 Average error = 4.3%

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

Lyman, W.J.  1985.   In: Environmental Exposure From Chemicals. Volume I., Neely,W.B. and Blau,G.E. (eds), Boca Raton, FL: CRC Press, Inc., Chapter 2.
Lyman, W.J., Reehl, W.F. and Rosenblatt, D.H.   1990.   Handbook of Chemical Property Estimation Methods.  Washington, DC: American Chemical Society, Chapter 14.

Specific details on test material used for the study:

SMILES: Oc1c(C(=O)Nc2ccc(O)cc2)cccc1

Temp.:

25 °C

Vapour pressure:

0 mm Hg

Remarks on result:

other: QSAR predicted value

MPBPVP predicted that 2-Hydroxy-N-(4-hydroxyphenyl)benzamide (also called osalmid) has a Vapour pressure Vp= 4.67E-10 mmHg (at 25ºC)

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

25 °C