Sulfuric acid, mono-C12-14(even numbered)-alkyl esters, ammonium salts

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Study period:

2010-04-28 to 2010-05-10

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

yes

Remarks:

not in appropriate range for Differential Scanning Calorimetry

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

GLP compliance:

no

Type of method:

other: Grain-Watson estimation

Temp.:

20 °C

Vapour pressure:

<= 0.18 Pa

Remarks on result:

other: by Grain-Watson estimation (1.8E-3 mbar)

Substance with a higher vapour pressure need to be assessed more critically, e.g. concerning the release of toxic substances, than those with a lower vapour pressure. For this reason, the calculation was based on the theoretically instead of the experimentally determined vapour pressure.

Reference 2

Endpoint:

vapour pressure

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

Refer to the Category Approach Justification document provided in IUCLID6 Section 13

Reason / purpose for cross-reference:

read-across source

GLP compliance:

no

Temp.:

20 °C

Vapour pressure:

<= 0.18 Pa

Remarks on result:

other: by Grain-Watson estimation (1.8E-3 mbar)

Reference 3

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2010-05-07 to 2010-05-11

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

yes

Remarks:

not in appropriate range for Differential Scanning Calorimetry

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Principles of method if other than guideline:

not reported

GLP compliance:

no

Type of method:

other: Grain-Watson estimation

Temp.:

20 °C

Vapour pressure:

9.9 Pa

Remarks on result:

other: by Grain-Watson estimation

Substance with a higher vapour pressure need to be assessed more critically, e.g. concerning the release of toxic substances, than those with a lower vapour pressure. For this reason, the calculation was based on the theoretically instead of the experimentally determined vapour pressure.

Description of key information

The vapour pressure is < 0.18 Pa at 20 °C (estimation).

Additional information

The value of vapour pressure is estimated based on the study reports of the substances ''Sulfuric acid, mono-C12 -14-alkyl (even numbered) esters, ammonium salts'' and ''sodium dodecyl sulphate C12''.

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

p_tot= ∑ p_ix_i

 

The vapour pressure of 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 -14-alkyl (even numbered) esters, ammonium salts'' should be lower than the vapour pressure of ''ammonium dodecyl sulphate C12''. Due to the similar chemical structure of ammonium salts and sodium salt, the vapour pressure of ammnoium salts should have the similar trend or be in the similar range like sodium salts. Therefore the vapour pressure of mixture ''Sulfuric acid, mono C12 -14-alkyl (even numbered) esters, ammonium salts'' is estimated to be lower than 0.18 Pa, the value is based on the experiment result for ''sodium dodecylsulphate''. This estimation is more reliable than the Grain-Watson calculation with the substance C12 -14 ammonium salts itself (result: < 9.9 Pa), which also is taken into account in the weight of evidence approach.