Registration Dossier

Administrative data

Endpoint:
vapour pressure
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 10/01/2018 to 20/09/2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 104 (Vapour Pressure Curve)
Version / remarks:
23 March 2006
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.4 (Vapour Pressure)
Version / remarks:
23 July 2009
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
effusion method: Knudsen cell

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Vapour pressureopen allclose all
Key result
Test no.:
#1
Temp.:
20 °C
Vapour pressure:
0.27 Pa
Key result
Test no.:
#1
Temp.:
25 °C
Vapour pressure:
0.45 Pa
Key result
Test no.:
#3
Temp.:
20 °C
Vapour pressure:
0.29 Pa
Key result
Test no.:
#3
Temp.:
25 °C
Vapour pressure:
0.49 Pa

Any other information on results incl. tables

Summary of Results

 

Trial

Vapour pressure at 293.15 K

Vapour pressure at 298.15 K

1

0.27 Pa

0.45 Pa

2

0.44 Pa

0.69 Pa

3

0.29 Pa

0.49 Pa

Mean1 and 3

0.28 Pa

0.47 Pa

 

The test item did not change in appearance under the conditions used in the determination.

 

The vapour pressure of Tri-n-hexylamine was measured using the Knudsen effusion method as described in EU method A.4 and OECD 104. Three trials were performed. For the second and third trial, five pairs temperature/mass loss were used to calculate corresponding vapour pressure of the substance at specified temperatures. For the first trial, four pairs temperature/mass loss were used to calculate corresponding vapour pressure of the substance at specified temperatures.

Then the logarithm of the vapour pressure log10(p(Pa)) is plotted against 1/T(K), and the regression curve is used to calculate the vapour pressure of the substance at 20°C and 25°C.

From the linear regression obtained in the first trial, the vapour pressure of test itemTri-n-hexylaminewas calculated as 0.27 Pa at 20°C and 0.45 Pa at 25°C.

From the linear regression obtained in the second trial, the vapour pressure of test item Tri-n-hexylamine was calculated as 0.44 Pa at 20°C and 0.69 Pa at 25°C.

The difference between the trials 1 and 2 at 25°C is more than 20%. Therefore, a third trial has been performed.

From the linear regression obtained in the third trial, the vapour pressure of test item Tri-n-hexylaminewas calculated as 0.29 Pa at 20°C and 0.49 Pa at 25°C.

The difference between the trials 1 and 3 at 25°C is less than 20%.

Therefore, the results of this study are considered valid.

In conclusion, the vapour pressure of Tri-n-hexylamine is 0.28 Pa at 20°C and 0.47 Pa at 25°C.

Applicant's summary and conclusion

Conclusions:
Three trials were conducted and four points were recorded for the first trial and five points were recorded for the second and third trial.
Log10 (Vapour Pressure (Pa)) was plotted against reciprocal temperature and values of vapour pressure were calculated at 20°C and 25°C with the linear function parameters (slope and intercept):

Trial Vapour pressure at 293.15 K Vapour pressure at 298.15 K
1 0.27 Pa 0.45 Pa
2 0.44 Pa 0.69 Pa
3 0.29 Pa 0.49 Pa
Mean of trials 1 and 3 0.28 Pa 0.47 Pa
The difference between the trials 1 and 2 at 25°C is more than 20%. Therefore, a third trial has been performed and the results of the second trial were not considered.
Calculated values respect validity criteria (less than 20% of difference) and the linear functions obtained own a correlation coefficient R² over 0.95.
Moreover the calculated values showed good correspondence with the experimentally determined ones.
In conclusion, the vapour pressure of Tri-n-hexylamine is 0.28 Pa at 20°C and 0.47 Pa at 25°C.
Executive summary:

A study was performed to determine the vapour pressure of the test item Tri-n-hexylamine under GLP. The method followed was designed to be compliant with the OECD Guideline for Testing of Chemicals No. 104, "Vapour Pressure", adopted in March 2006 and Regulation (EC) No 761/2009, EC A4, 23 July 2009.

In this dynamic method, the mass of the test substance flowing out per unit of time of a Knudsen cell in the form of vapour, through a micro-orifice under ultra-vacuum conditions was determined at various specified temperatures (from 22.4 to 43.8°C). The Hertz-Knudsen equation was used to calculate the vapour pressure corresponding to the mass loss rate.

The Log10 (Vapour Pressure (Pa)) was plotted against 1/T (K) and a linear function was obtained. With this equation, the vapour pressure has been calculated for temperatures of 20°C and 25°C.

Three trials were conducted and four points were recorded for the first trial and five points were recorded for the second and third trial.

Log10 (Vapour Pressure (Pa)) was plotted against reciprocal temperature and values of vapour pressure were calculated at 20°C and 25°C with the linear function parameters (slope and intercept):

Trial       Vapour pressure at 293.15 K       Vapour pressure at 298.15 K

1                            0.27 Pa                                   0.45 Pa

2                            0.44 Pa                                   0.69 Pa

3                            0.29 Pa                                   0.49 Pa

Mean of trials 1 and 3       0.28 Pa                         0.47 Pa

The difference between the trials 1 and 2 at 25°C is more than 20%. Therefore, a third trial has been performed and the results of the second trial were not considered.

Calculated values respect validity criteria (less than 20% of difference) and the linear functions obtained own a correlation coefficient R² over 0.95.

Moreover the calculated values showed good correspondence with the experimentally determined ones.

In conclusion, the vapour pressure of Tri-n-hexylamine is 0.28 Pa at 20°C and 0.47 Pa at 25°C.