[2-[[4-[(2-chloro-4-nitrophenyl)azo]phenyl]ethylamino]ethyl](2-hydroxypropyl)dimethylammonium 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:

June 24, 2015 - July 19, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study (EC A.4. and OECD 104)

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

not applicable

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

not applicable

GLP compliance:

no

Type of method:

effusion method: vapour pressure balance

Key result

Temp.:

20 °C

Vapour pressure:

0 Pa

Temp.:

25 °C

Vapour pressure:

0 Pa

Temp.:

50 °C

Vapour pressure:

0.001 Pa

Vapour pressure balance

The first measurement was performed in the temperature range of 50 °C to 90 °C. This measurement showed an ambiguous behavior. Therefore a second measurement was done. Before this measurement was started the test item was kept at 50 °C for 24 h under vacuum to remove volatile impurities. The vapour pressure was measured in the temperature range of 50 °C to 90 °C. The measured vapour pressures at the corresponding temperatures are listed in Table 1.

Table1: Measured vapour pressures and corresponding temperatures

Temperature [°C]	Vapour pressure [hPa]
50*	1.6 × 10^-4
60*	1.2 × 10^-4
70*	6.1 × 10^-5
80*	4.5 × 10^-5
90*	4.0 × 10^-5
50**	7.0 × 10^-6
60**	2.1 × 10^-5
70**	4.1 × 10^-5
80**	5.2 × 10^-5
90**	4.9 × 10^-5

*  First measurement

** Second measurement

Both measurements showed an ambiguous behaviour. Due to the possible influence of volatile impurities in the first measurement it was repeated. Therefore, a new portion of the test item was kept at 50 °C under vacuum for 24 h to remove these impurities. However the second measurement also showed an ambiguous behaviour especially at the last two temperatures. As conservative approach the first three measurement points of the second measurement were evaluated. It cannot be excluded that this evaluation was still influenced by volatile impurities.The values for 20, 25 and 50 °C are calculated, using the Antoine constants A, B and C as follows:

T [°C]	p [hPa]	Log (p/hPa) = A + B/(C+T[°C])
20	3.40E-07	A = 7.99787
25	5.95E-07	B = -4240.68
50	7.50E-06	C = 273.15

 

Conclusions:

The vapour pressure of the test item at 20°C was determined to be 3.4E-07 hPa.

Executive summary:

The vapour pressure of the test item was determined according to methods OECD 109 and EU A.4 (vapour pressure balance).

The following vapour pressure values for the test item were extrapolated from the experimental data:

T [°C]	p [hPa]	p [Pa]
20	3.4×10^-7	3.4×10^-5
25	6.0×10^-7	6.0×10^-5
50	7.5× 10^-6	7.5× 10^-4

Description of key information

The vapour pressure of the test item using the vapour pressure balance method (OECD 104/EU A.4) was determined as follows:

T [°C]	p [hPa]	p [Pa]
20	3.4×10^-7	3.4×10^-5
25	6.0×10^-7	6.0×10^-5
50	7.5× 10^-6	7.5× 10^-4

Key value for chemical safety assessment

Vapour pressure:

0 hPa

at the temperature of:

20 °C