2,2'-[oxybis(2,1-ethanediyloxy)]bisacetic acid

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 2017-04-25 to 2018-02-16

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

Specific details on test material used for the study:

Batch no.: 03/2016_T_R_JM

Key result

Temp.:

20 °C

Vapour pressure:

0 Pa

Temp.:

25 °C

Vapour pressure:

0 Pa

Experiment 1-4 and 9 (nominal temperature 30 - 75 and 150 °C) showed no reproducible weight loss. Therefore, they were not used for calculation.

A graph with log P vs. 1/T was plotted. Since the values were correlated by a linear relation, the data could be fitted by linear regression.

Table 1. Parameters of linear regression

Parameter	Value
Slope	-4261.1
Intercept	10.3379
Correlation Coefficient r	-0.9907
Coefficient of Determination r^2	0.9815

 

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

Table 2. Experimentally determined vapour pressures

T	T	P	Stand. Dev. P	RSD P
°C	K	Pa	Pa	%
90.0	363.2	4.32E-02	1.05E-03	2.4%
105.0	378.2	1.19E-01	1.80E-02	15.1%
120.0	393.2	2.48E-01	5.49E-02	22.2%
135.0	408.2	9.35E-01	2.34E-01	25.0%

 

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

Vapour pressure at 20 °C:	6.34 * 10^-5Pa
Vapour pressure at 25 °C:	1.11 * 10^-4Pa

The linear regression of log P vs. 1/T gave a correlation coefficient r of - 0.9907, showing good repeatability and precision. Therefore, the determination is considered as valid.

Positive Control

Vapour pressure (positive control) at 30 °C:	2.03 * 10^-1Pa
Criteria for the vapour pressure of the positive control at 30 °C	1.44 * 10^-1± 0.1 Pa

The vapour pressure of the positive control met the validity criteria. Therefore, the study can be considered as valid.

The vapour pressure of the test item was determined at nine different temperatures (30, 45, 60, 75, 90, 105, 120, 135 and 150 °C) according to OECD 104 resp. EU A.4 using the effusion method (weight loss). Experiment 1-4 and 9 (nominal temperature 30 - 75 and 150 °C) showed no reproducible weight loss. When visible contaminations, caused by explosive evaporation of the test item, were observed, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, these measurements were not used for calculations. Four experiments could be evaluated as they showed relevant and reproducible weight loss. All evaluated experiments showed good reproducibility, giving relative standard deviations of less than 25 % and good correlation. Therefore, the result of the test can be considered valid.

Conclusions:

The vapour pressure of the test item was estimated to be 6.34E-5 Pa at 20 °C and 1.11E-4 Pa at 25 °C, respectively.

Executive summary:

A study was conducted according to OECD TG 104, Regulation (EC) No 440/2008 method A.4 and OPPTS 830.7950 to determine the vapour pressure of the test item. The vapour pressure of the test item was determined at temperatures between 30 and 150 °C using the effusion method (Knudsen cell). For the evaluation the vapour pressure values at temperatures of 90, 105, 120 and 135 °C were used. The vapour pressure of the test item was calculated by extrapolation of the measured vapour pressure curve for the temperatures 20 and 25 °C. The vapour pressure was calculated to be 6.34E-5 Pa at 20 °C and 1.11E-4 Pa at 25 °C, respectively.

Description of key information

The vapour pressure of the test item was estimated to be 6.34E-5 Pa at 20 °C and 1.11E-4 Pa at 25 °C, respectively.

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C

Additional information

A study was conducted according to OECD TG 104, Regulation (EC) No 440/2008 method A.4 and OPPTS 830.7950 to determine the vapour pressure of the test item. The vapour pressure of the test item was determined at temperatures between 30 and 150 °C using the effusion method (Knudsen cell). For the evaluation the vapour pressure values at temperatures of 90, 105, 120 and 135 °C were used. The vapour pressure of the test item was calculated by extrapolation of the measured vapour pressure curve for the temperatures 20 and 25 °C. The vapour pressure was calculated to be 6.34E-5 Pa at 20 °C and 1.11E-4 Pa at 25 °C, respectively.