Octanoic acid, ester with 1,2,3-propanetriol

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

April 2017

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
EPISuite (v4.11)
2. MODEL (incl. version number)
MPBPWIN v1.43
3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CAS-no.
4. Background of the (Q)SAR Model
This program (MPBPWIN) estimates the boiling point (at 760 mm Hg), melting point and vapor pressure of organic compounds. MPBPWIN requires only a chemical structure to make these predictions. Structures are entered into MPBPWIN by SMILES (Simplified Molecular Input Line Entry System) notations. A discussion of the encoding rules for SMILES notation can be found in the document "A Brief Description of SMILES Notation"; an on-line version of this document is available from the MPBPWIN Help menu. The estimation methodologies used by MPBPWIN are outlined in the methodology sections for Boiling Point, Melting Point and Vapor Pressure.
MPBPWIN can estimate vapor pressure at different temperatures (see VP Temperature Considerations section).
MPBPWIN can import and use MDL MOL files. It does this by converting the MOL file format to SMILES notations and then using the converted SMILES (see section 5.4).

The estimation methodology for boiling point has been adapted from the Stein and Brown method ("Estimation of Normal Boiling Points from Group Contributions", J. Chem. Inf. Comput. Sci. 34: 581-87, 1994).  Melting Point is estimated by two different methods; the first is the Joback Group Contribution Method, and the second is a Gold and Ogle method which simply uses the following formula:  Tm = 0.5839 Tb  where Tm is the melting point in Kelvin and Tb is the boiling point in Kelvin. Although Melting Point estimation can be inaccurate, we have found that averaging the results of these two methods can yield reasonable estimates for many structures.

Vapor Pressure is estimated by three methods; all three methods use the boiling point.  The first is the Antoine method (see Chapter 14 of W.J. Lyman's book "Handbook of Chemical Property Estimation Methods", Washington, DC: American Chemical Society, 1990). The second is the modified Grain method (see page 31 of Neely and Blau's Environmental Exposure from Chemicals, Volume I, CRC Press, 1985).  The third is the Mackay method (see page 31-2 of Neely and Blau's Environmental Exposure from Chemicals, Volume I, CRC Press, 1985).  For solids, a melting point is required to adjust the vapor pressure from a subcooled (supercooled) liquid to a solid.  Data entry allows measured BP and MP to be to used; when entered, the measured values are used instead of the estimated values.  The preferred VP method for solids is the Modified Grain method, although the Antoine method in this program is nearly as good because it uses the exact same methodology to convert super-cooled VP to solid VP.  For liquids, the mean of the Grain and Antoine methods is preferred.  The Mackay method is not as applicable to as many chemical classes as the other methods, so it is generally not preferred.

The current version of MPBPWIN calculates and reports the subcooled liquid vapor pressure for solid compounds.  Under the EPI Suite, subcooled vapor pressure values are passed to the AEROWIN Program to estimate atmospheric particulate sorption.

Descriptions of the MPBPWIN  Data Entry Fields:
SMILES Notation:  this is the structure of the chemical.
Chemical Name: the name, description, and/or identification of the compound.  It is for identification purposes only and is not required.

Measured Boiling Pt (deg C):   this field is optional and is not required.  If a measured boiling point is available, it should be entered here.  It is used in estimating Vapor Pressure; if this field is blank, the estimated BP will be used instead.  To blank this field, use the Del or Back Space keys to erase all characters, or simply add a space at the first position and hit the Tab key.

Measured Melting Pt (deg C):   this field is optional and is not required.  If a measured melting point is available, it should be entered here.  It is used in estimating the Vapor Pressure of solids; if this field is blank, the estimated MP will be used instead.  Melting point is not used in estimating Vapor Pressure of liquids. To blank this field, use the Del or Back Space keys to erase all characters, or simply add a space at the first position and hit the Tab key.

Temperature for Vapor Pressure (deg C):   this is the temperature at which the vapor pressure will be estimated.  The default is 25 deg C.

Principles of method if other than guideline:

- Software tool(s) used including version: EPISuite v4.11
- Model(s) used: MPBPWIN v1.68
- Method description: 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.
- Justification of QSAR prediction: see field 'Justification for type of information'

Type of method:

other: Calculation

Specific details on test material used for the study:

Octanoic acid, ester with 1,2,3-propanetriol contains 50% octanoic acid, monoester with glycerol (26402-26-6), 40% dioctanoic acid, diester with glycerol (36534-80-0), 10% glycerol trioctanoate (538-23-8).

Key result

Temp.:

25 °C

Vapour pressure:

>= 0 Pa

Key result

Remarks on result:

not measured/tested

Calculation from the main components.

CAS Number: 26402-26-6

SMILES : O=C(OCC(O)CO)CCCCCCC

CHEM   : Octanoic acid, monoester with 1,2,3-propanetriol

MOL FOR: C11 H22 O4

MOL WT : 218.30

Boiling Pt, Melting Pt, Vapor Pressure Estimations (MPBPVP v1.43):

Boiling Pt (deg C):  331.72  (Adapted Stein & Brown method)

Melting Pt (deg C):  84.79  (Mean or Weighted MP)

VP(mm Hg,25 deg C):  2.33E-006  (Modified Grain method)

VP (Pa, 25 deg C) :  0.000311  (Modified Grain method)

Subcooled liquid VP: 8.71E-006 mm Hg (25 deg C, Mod-Grain method); 0.00116 Pa (25 deg C, Mod-Grain method)

CAS Number: 36354-80-0

SMILES : CCCCCCCC(=O)OCC(O)COC(=O)CCCCCCC

CHEM   :

MOL FOR: C19 H36 O5

MOL WT : 344.50

Boiling Pt, Melting Pt, Vapor Pressure Estimations (MPBPVP v1.43):

Boiling Pt (deg C):  391.10  (Adapted Stein & Brown method)

Melting Pt (deg C):  45.13  (Mean or Weighted MP)

VP(mm Hg,25 deg C):  2.21E-007  (Modified Grain method)

VP (Pa, 25 deg C) :  2.95E-005  (Modified Grain method)

Subcooled liquid VP: 3.37E-007 mm Hg (25 deg C, Mod-Grain method); 4.5E-005 Pa (25 deg C, Mod-Grain method)

VP (Pa, 25 deg C): >= 0.000311

Conclusions:

The estimated VP was >= 0.000311 Pa. The MPBPWIN calculate vapour pressure value is considered valid and fit for purpose.

Executive summary:

Vapour pressure for Octanoic acid, ester with 1,2,3-propanetriol was calculated by Modified Grain method.

With the program MPBPWIN v1.43 (part of US EPA EPI Suite v4.11), a Vapour pressure of >= 0.000311 Pa was determined.

Description of key information

Calculated by the main constituents.

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

25 °C