Tris(2-hydroxyethyl)ammonium chloride

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2017-05-02 to 2017-06-30

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:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: Knudsen cell

Key result

Temp.:

20 °C

Vapour pressure:

0 Pa

Temp.:

25 °C

Vapour pressure:

0 Pa

All calculation results are given in the tables below. In all tables, E-0X represents multiplication with 10-X. Experiments 1 to 4 and 9 (nominal temperature 30 to 75 and 150 °C) showed no reproducible weight loss. Therefore, these values were not used for calculation.

Calculation Results Experiment 5

Experiment	5
Real Temperature in K	363.2
Real Temperature in °C	90.0
Date of Measurement	02.06.2017 12:30				07.06.2017 10:10			08.06.2017 12:10
Elapsed Time in s	85800				81000			89400
Parameter	Weight loss	to be used		Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no		Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.00152	yes		7.93E-03	0.00168	yes	9.29E-03	0.00093	yes	4.66E-03
Knudsen-cell 2	0.00124	yes		6.47E-03	0.00121	yes	6.69E-03	0.00047	no
Knudsen-cell 3	0.00111	yes		5.79E-03	0.00091	yes	5.03E-03	0.00086	yes	4.31E-03
Knudsen-cell 4	0.00202	yes		1.05E-02	0.00110	yes	6.08E-03	0.00100	yes	5.01E-03
Mean		yes		7.69E-03		yes	6.77E-03		yes	4.66E-03
Standard deviation:				2.10E-03			1.81E-03			3.51E-04
Mean of measured values:				6.372E-03
Standard deviation:				1.553E-03	RSD:	24.4%

If “no” is stated in the respective column: measurement was not considered for the calculation of the mean.

Calculation Results Experiment 6

Experiment	6
Real Temperature in K	378.2
Real Temperature in °C	105.0
Date of Measurement	09.06.2017 11:25				13.06.2017 11:55			14.06.2017 11:50
Elapsed Time in s	81600				92700			83700
Parameter	Weight loss	to be used		Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no		Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.00620	yes		3.47E-02	0.00639	yes	3.15E-02	0.00552	yes	3.01E-02
Knudsen-cell 2	0.00431	yes		2.41E-02	0.00463	yes	2.28E-02	0.00365	yes	1.99E-02
Knudsen-cell 3	0.00356	yes		1.99E-02	0.00460	yes	2.27E-02	0.00317	yes	1.73E-02
Knudsen-cell 4	0.00554	yes		3.10E-02	0.00577	yes	2.84E-02	0.00492	yes	2.69E-02
Mean		yes		2.75E-02		yes	2.64E-02		yes	2.36E-02
Standard deviation:				6.66E-03			4.35E-03			5.96E-03
Mean of measured values:				2.579E-02
Standard deviation:				2.010E-03	RSD:	7.8%

Calculation Results Experiment 7

Experiment	7
Real Temperature in K	393.2
Real Temperature in °C	120.0
Date of Measurement	20.06.2017 11:55				21.06.2017 12:00			22.06.2017 12:00
Elapsed Time in s	88500				83400			83400
Parameter	Weight loss	to be used		Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no		Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.02686	yes		1.41E-01	0.02612	yes	1.46E-01	0.02612	yes	1.46E-01
Knudsen-cell 2	0.01797	yes		9.46E-02	0.01856	yes	1.04E-01	0.01887	yes	1.05E-01
Knudsen-cell 3	0.01800	yes		9.48E-02	0.01872	yes	1.05E-01	0.01882	yes	1.05E-01
Knudsen-cell 4	0.02227	yes		1.17E-01	0.02254	yes	1.26E-01	0.02216	yes	1.24E-01
Mean		yes		1.12E-01		yes	1.20E-01		yes	1.20E-01
Standard deviation:				2.23E-02			2.01E-02			1.93E-02
Mean of measured values:				1.174E-01
Standard deviation:				4.644E-03	RSD:	4.0%

Calculation Results Experiment 8

Experiment	8
Real Temperature in K	408.2
Real Temperature in °C	135.0
Date of Measurement	23.06.2017 12:35				27.06.2017 12:50			28.06.2017 12:10
Elapsed Time in s	85500				88800			84600
Parameter	Weight loss	to be used		Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no		Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.10006	yes		5.56E-01	0.05456	yes	2.92E-01	0.08235	yes	4.62E-01
Knudsen-cell 2	0.07189	yes		3.99E-01	0.04088	yes	2.19E-01	0.05959	yes	3.34E-01
Knudsen-cell 3	0.07448	yes		4.14E-01	0.04167	yes	2.23E-01	0.06041	yes	3.39E-01
Knudsen-cell 4	0.08348	yes		4.64E-01	0.05093	yes	2.72E-01	0.07209	yes	4.05E-01
Mean		yes		4.58E-01		yes	2.51E-01		yes	3.85E-01
Standard deviation:				7.07E-02			3.63E-02			6.06E-02
Mean of measured values:				3.648E-01
Standard deviation:				1.048E-01	RSD:	28.7%

The measured values for temperature and vapour pressure were evaluated as follows:

Evaluation of Calculated Values

Parameter	T	Mean P	1/T	log P
Unit	K	Pa	1/K	log Pa
Values	363.2	6.37E-03	2.7533E-03	-2.1957
	378.2	2.58E-02	2.6441E-03	-1.5885
	393.2	1.17E-01	2.5432E-03	-0.9305
	408.2	3.65E-01	2.4498E-03	-0.4380

Parameters of Linear Regression

Parameter	Value
Slope	-5865.7
Intercept	13.9487
Correlation Coefficient r	-0.9993
Coefficient of Determination r²	0.9985

The following vapour pressures were determined experimentally and considered as valid (mean and standard deviation given):

Experimentally determined vapour pressures

T (°C)	T (K)	Pressure (Pa)	Stand. Dev. Pressure (P)	RSD Pressure
90.0	363.2	6.37E-03	1.55E-03	24.4%
105.0	378.2	2.58E-02	2.01E-03	7.8%
120.0	393.2	1.17E-01	4.64E-03	4.0%
135.0	408.2	3.65E-01	1.05E-01	28.7%

In this table, E-0X represents multiplication with 10^-X.

Stand. Dev. = Standard Deviation; RSD = Relative Standard Deviation

For the test item the vapour pressures at 20 °C and at 25 °C were calculated from the regression equation (see results above).

The linear regression of log P vs.¹/_T gave a correlation coefficient r of -0.9993, showing good repeatability and precision. Therefore, the determination is considered as valid.

Conclusions:

For the test item the following vapour pressures at 20 °C and 25 °C were calculated from the regression equation:
- at 20 °C: 8.70E-7 Pa
- at 25 °C: 1.88E-6 Pa

Executive summary:

A study was performed in order to determine the vapour pressure of the test item according to OECD TG 104 and Regulation (EC) No. 440/2008, method A.4, by using the effusion method (weight loss). The vapour pressure was determined at nine different temperatures (30, 45, 60, 75, 90, 105, 120, 135 and 150 °C). The experiments 5 to 8 (temperatures 90, 105, 120 and 135 °C) showed relevant and reproducible weight loss and were used for the further calculations. These experiments showed good reproducibility, giving relative standard deviations of less than 29 % and very good correlation. Therefore, the results of the test could be considered valid. For the test item the following vapour pressures were calculated from the regression equation: 8.70xE-07 Pa at 20 °C and 1.88 x E-06 Pa at 25 °C [reference 4.6 -1].

Description of key information

For the test item the following vapour pressures at 20 °C and 25 °C were calculated from the regression equation:

- at 20 °C: 8.70E-7 Pa

- at 25 °C: 1.88E-6 Pa

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C

Additional information

A study was performed in order to determine the vapour pressure of the test item according to OECD TG 104 and Regulation (EC) No. 440/2008, method A.4, by using the effusion method (weight loss). The vapour pressure was determined at nine different temperatures (30, 45, 60, 75, 90, 105, 120, 135 and 150 °C). The experiments 5 to 8 (temperatures 90, 105, 120 and 135 °C) showed relevant and reproducible weight loss and were used for the further calculations. These experiments showed good reproducibility, giving relative standard deviations of less than 29 % and very good correlation. Therefore, the results of the test could be considered valid. For the test item the following vapour pressures were calculated from the regression equation: 8.70xE-07 Pa at 20 °C and 1.88 x E-06 Pa at 25 °C (reference 4.6 -1).