Potassium isooctadecanoate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

no

Type of method:

dynamic method

Remarks:

Determination of the vapour pressure curve of solid and liquid substances by means of DSC.

Specific details on test material used for the study:

Product description: Potassium isooctadecanoate/potassium isostearate
Name: Isooctadecanoic acid, potassium salt
CAS No.: 66469-15-6
Physical state: off white to yellowish solid at 20 °C
Batch No.: PFS-755-169
Re-certification date of batch: 12 December 2017
Purity: 100 % (UVCB)
pH, 10% in DI water 8.0 - 9.0
Stability: stable under test conditions
Storage condition of test material: Room temperature, protected from light

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

<= 0 Pa

Remarks on result:

other: Vapour pressure calculated (Determination of the vapour pressure curve of solid and liquid substances by means of DSC).

Key result

Test no.:

#2

Temp.:

50 °C

Vapour pressure:

<= 0.006 Pa

Remarks on result:

other: Vapour pressure calculated (Determination of the vapour pressure curve of solid and liquid substances by means of DSC).

Study Results

The test item Isooctadecanoic acid, potassium salt has a vapour pressure of ≤ 1.1 x 10^-9 atm (≤ 1.1 x 10^-4 Pa; ≤ 1.1 x 10^-6 mbar) at 20 °C and of ≤ 5.9 x 10^-8 atm (≤ 6.0 x 10^-3 Pa; ≤ 6.0 x 10^-5 mbar) at 50 °C (the calculation is based on the lowest possible boiling temperature) according to the definition in the OECD Guideline 104 (Grain-Watson estimation).

The experimentally determined vapour pressure of the test item at 20 °C is not in the recommended range of 1 to 1000 mbar for DSC-measurements. Therefore an estimation procedure in accordance with the test method OECD Guideline 104 “OECD Guideline For The Testing Of Chemicals, adopted by the Council on 23rd March 2006, Vapour Pressure” ANNEX Estimation Method newest version (Robert S. Boethling, Donald Mackay, Handbook of Property Estimation Methods for Chemicals, Lewis Publishers, year of publication 2000, Cap. 3 - Vapour Pressure, Grain-Watson Method, p. 53 – 65) was used. This method is applied for vapour pressures between 10^3 to 10^-7 mbar. This deviates from the older version published in OECD Guideline 104. It was used due to the differentiation between solids and liquids, which results in a more precise estimate.

Conclusions:

The test item has a vapour pressure of ≤ 1.1 x 10^-4 Pa at 20 °C and of ≤ 6.0 x 10^-3 Pa at 50 °C according to the definition in the OECD Guideline 104 (Grain-Watson estimation). The calculation is based on the lowest possible boiling temperature determined by DSC.

Executive summary:

The test item has a vapour pressure of ≤ 1.1 x 10^-9 atm (≤ 1.1 x 10^-4 Pa; ≤ 1.1 x 10^-6 mbar) at 20 °C and of ≤ 5.9 x 10^-8 atm (≤ 6.0 x 10^-3 Pa; ≤ 6.0 x 10^-5 mbar) at 50 °C (the calculation is based on the lowest possible boiling temperature) according to the definition in the OECD Guideline 104 (Grain-Watson estimation).

Description of key information

The test item has a vapour pressure of ≤ 1.1*10^-4 Pa at 20 °C and of ≤ 6.0*10^-3 Pa at 50 °C according to the definition in the OECD Guideline 104 (Grain-Watson estimation). The calculation is based on the lowest possible boiling temperature determined by DSC.

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C