Registration Dossier

Diss Factsheets

Physical & Chemical properties

Vapour pressure

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The vapour pressure is < 0.18 Pa at 25 °C (estimation method).

Key value for chemical safety assessment

Vapour pressure:
0.18 Pa
at the temperature of:
25 °C

Additional information

The test substance was investigated using the static method. The result was < 5 Pa at two temperatures: 20 and 50 °C.

Since the data for the test substace C12-13 were obtained for a high water content (ca. 73%) formulation, the value of vapour pressure was estimated in a weight of evidence approach, including data for read-across substances sulfuric acid, mono-C12-14-alkyl (even numbered) esters, sodium salts, and sodium dodecyl sulphate.

According to the theoretical principle of Raoult’s law, the vapour pressure of a mixture is equal to the mole-fraction-weighted sum of the components' vapour pressures:

ptot= ∑ pixi


The vapour pressure of a mixture should be lower than the vapour pressure of the component which has the highest vapour pressure in its pure form.


Therefore the vapour pressure of Sulfuric acid, mono-C12-13 branched & linear alkyl esters, sodium salts should be lower than the vapour pressure of sodium dodecyl sulphate C12. This is why the value for C12 (< 0.18 Pa) is more reliable than the value obtained for C12-13 (high water content formulation) and the one calculated for C12-14 (< 97 Pa), also used in the weight of evidence approach. This value was selected for chemical safety assessment.