4,4'-methylenebis(2,6-xylidine)

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 November 2017 - 19 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. No deviation was reported. The test substance is adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

2006

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP compliance programme (inspected on 13 and 14 October 2014 / signed on 08 April 2015)

Type of method:

effusion method: Knudsen cell

Remarks:

effusion method (weight loss)

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0 Pa

Remarks on result:

other: extrapolated from regression equation

Key result

Test no.:

#2

Temp.:

25 °C

Vapour pressure:

0 Pa

Remarks on result:

other: extrapolated from regression equation

All the tables and experimental raw data are included in the experimental report.

Evaluation

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

Table 4.6/3.- Evaluation of Calculated Values

Parameter	T	Mean p	1/T	log p
Unit	K	Pa	1/K	log Pa
Values	348.2	0.0109	2.8719E-03	-1.9624
	363.2	0.0726	2.7533E-03	-1.1389
	378.2	0.410	2.6441E-03	-0.3871

A graph with log p vs. 1/T was plotted (see experimental report). Since the values were correlated by a linear relation, the data could be fitted by linear regression.

y = -6915,3x + 17,899
R² = 1

Table 4.6/4.- Parameters of Linear Regression

Parameter	Value
Slope	-6915.3
Intercept	17.8988
Correlation Coefficient r	-1.0000
Coefficient of Determination r^2	1.0000

Results

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

Table 4.6/5.- Experimentally Determined Vapour Pressures

T	T	p	Stand. Dev. p	RSD p
°C	K	Pa	Pa	%
75.0	348.2	0.0109	0.002	18.3%
90.0	363.2	0.0726	0.00295	4.1%
105.0	378.2	0.410	0.0106	2.6%

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

 Table 4.6/6.- Results Test Item

Vapour pressure at 20°C:	2.04* 10^-06Pa
Vapour pressure at 25°C:	5.07* 10^-06Pa

 

The linear regression of log p vs. 1/T gave a correlation coefficient r of – 1.0000, showing good repeatability and precision. Therefore, the determination is considered as valid.

Discussion

The vapour pressure of the test item was determined at six different temperatures (30, 45, 60, 75, 90 and 105 °C) according to OECD 104 resp. EU A.4 using the effusion method (weight loss). Experiment 1 - 3 (nominal temperature 30 - 60 °C) showed only a poor reproducible weight loss. When visible contaminations, caused by 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.

Three experiments could be evaluated as they showed relevant and repeatable weight loss. All evaluated experiments showed good repeatability, giving relative standard deviations of less than 19 % (limit value from the guideline 30 %) and perfect correlation.

Therefore, the result of the test can be considered valid.

Conclusions:

The vapour pressure of the test item was stated to be at 20 °C: 2.04*E06 Pa

Executive summary:

The vapour pressure of the test item was determined according to OECD 104 resp.EU A.4 using the effusion method (weight loss) under GLP.

 

Vapour pressure was examined at six different temperatures.Three temperatures could be evaluated as they showed reproducible weight loss. For these temperatures, 1/T was plotted against log (p). The graph 1/T vs. log (P) shows a straight line with a correlation coefficient (r) of - 1.0000. For the test item, the vapour pressures at 20 °C and at 25 °C were calculated from the regression equation.

Vapour pressure at 20 °C:        2.04* 10^-06Pa

Vapour pressure at 25 °C:        5.07* 10^-06Pa

Description of key information

Vapour pressure at 20 °C: 2.04E^-06Pa (Low volatility)

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C

Additional information

A fully reliable experimental study, conducted according to a recognized OECD/EC method and under GLP, is available. Therefore, it is considered as a key study, and the result is retained as key data.