Phosphonic acid, monoethyl ester, sodium salt (1:1)

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24-26 Apr 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium für Umwelt, Energie, Jugend, Familie und Gesundheit, Wiesbaden

Type of method:

effusion method: vapour pressure balance

Temp.:

20 °C

Vapour pressure:

< 0 hPa

Temp.:

50 °C

Vapour pressure:

< 0 hPa

Transition / decomposition:

yes

Transition temp.:

250 °C

The decomposition starting at 250 °C was determined in a preliminary measurement of thermal stability (DSC method). The actual vapour pressure measurements were conducted in the range 20 °C - 145 °C. No signal was observed in the whole range. Thus, the vapour pressure in the whole range was below the lower detection limit of 1E-05 hPa.

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

supporting study

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
EPI Suite version 4.11

2. MODEL (incl. version number)
Mpbpwin v. 1.43

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer. Further information on the OECD criteria as outlined by the applicant is provided below under "Any other information of materials and methods incl. tables"

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on results incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other: REACH Guidance on QSARs

Principles of method if other than guideline:

- Software tool(s) used including version: EPI Suite v4.11
- Model(s) used: Mpbpwin Model version 1.43
The model estimates vapour pressure by three different methods:
- the Antoine equation (Lyman WJ, Reehl WF and Rosenblatt DH. 1990. Handbook of Chemical Property Estimation Methods. Washington, DC: American Chemical Society);
- the Modified Grain Method (Lyman WJ. 1985. In: Environmental Exposure From Chemicals. Volume I. Neely WB and Blau GE (eds). Boca Raton, FL: CRC Press, Inc., Chapter 2);
- the Mackay Method (Lyman WJ. 1985. In: Environmental Exposure From Chemicals. Volume I. Neely WB and Blau GE (eds). Boca Raton, FL: CRC Press, Inc.).
MPBPWIN selects a “suggested” vapour pressure: the modified Grain for solids and the average of the Antoine and the modified Grain for liquids and gases.
A dataset of 3037 compounds with experimentally determined vapour pressure values has been used to evaluate the model (using the “suggested” values as outcome), giving a correlation coefficient of 0.914. The evaluation clearly shows that the model reliability decrease for vapour pressure below 0.0001 Pa.
The dataset contains 1642 compounds with available experimental Boiling points and Melting points. The correlation coefficient evaluated on this subset (0.949) indicates that VP estimates are more accurate when experimental BP and MP are available.

- Model description: see field 'Justification for type of information', 'Attached justification' and 'any other information on Material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Type of method:

other: QSAR

Temp.:

20 °C

Vapour pressure:

0 Pa

Remarks on result:

other: modified Grain method

Modified Grain method. QSAR result; transition/decomposition is not specified/reported. For detailed description of the model and its applicability, see "Any other information on materials and methods incl. tables”

Description of key information

< 0.00001 hPa at 20 °C

Key value for chemical safety assessment

Vapour pressure:

0 hPa

at the temperature of:

20 °C

Additional information

The vapour pressure of the substance was determined according to OECD Guideline 104 and EU Method A.4 (effusion method - vapour pressure balance). The measured value was below the detection limit of 1E-05 hPa in the temperature range between 20 °C and 50 °C. Since no exact value was obtained in the experiment, QSAR model result (EPI Suite, MPBP v1.43) is used as supporting. The calculated value of 1.52E-07 Pa (1.52E-09 hPa) is in the range resulting from the experiment (< 1.0E-05 hPa).