Bis(acetato-O)hydroxyaluminium

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 2015-05-04 to 2015-06-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

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

Vapour pressure:

< 0 Pa

The vapour pressure was measured in the temperature range of 30 °C to 60 °C. There was no vapour pressure measurable. The vapour pressure of the test item was below the detection limit of 10^-5 hPa.

Since the test did not yield vapour pressures sufficiently high to extrapolate to 20, 25 and 50 °C these values were estimated. According to the Antoine equation, the vapour pressure can be calculated according to:

 

log(p/hPa)=A + B/(C + (T/°C))

 

p: Vapour pressure in hPa

T: Temperature in °C

A, B, C: Antoine constants

 

For an extrapolation to lower temperatures a conservative assumption of the Antoine constant C is 273.15. This results in a linear dependency of log(p) of the inverse Temperature 1/T (in K). Values for the resulting slope of the Antoine equation (constant B)for substances of high molecular weight, which can be derived from literature values, are lower than -5000. Thus, for a conservative estimation of the vapour pressure of the test item at 20, 25 and 50 °C, a value of -5000 for constant B and a value of 273.15 for constant C, respectively, were used.

The last data point of the measurement at 60 °C was used as the starting point for the calculation. The measured vapour pressure at 60 °C was below the detection limit of 10^-5 hPa. Thus, the detection limit (1.0 x 10^-5 hPa) at the highest measurement point (60 °C) was used for the calculation as all measured vapour pressures were below this limit.

 

Based on this assumption, the constant Aof the Antoine equation was calculated according to:

 

A = log(p/hPa) – (-5000/(273.15+T[°C])) = 1.0 · log10^-5 – (-5000/(273.15+60)) = 10.01

 

Subsequently, the vapour pressure at 20, 25 and 50 °C can be calculated with the Antoine equation as follows:

 

log(p/hPa) = 10.01 + (-5000/(273.15+T[°C]))

 

 

Table 1: Calculated vapour pressure at 20, 25 and 50 °C

T/°C	p/hPa	p/Pa
20	<9.0 x 10^-8	< 9.0 x 10^-6
25	< 1.7 x 10^-7	< 1.7 x 10^-5
50	< 3.4 x 10^-6	< 3.4 x 10^-4

 

Conclusions:

The vapour pressure of the test item was below the detection limit of 1.0E-5 hPa. The vapour pressure was calculated using the linear regression equation of the Log P versus 1/T function at 20, 25 and 50 °C. It was calculated to be <9.0E-6 Pa at 20 °C and <1.7E-5 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 could not be determined experimentaly using the effusion method (weight loss). The vapour pressure of the test item was below the detection limit of 10^-5 hPa. The vapour pressure was calculated using the linear regression equation of the Log P versus 1/T function at 20, 25 and 50 °C. It was calculated to be <9.0E-6 Pa at 20 °C and <1.7E-5 at 25 °C, respectively.

Description of key information

The vapour pressure of the test item was calculated to be <9.0E-6 Pa at 20 °C and <1.7E-5 at 25 °C, respectively.

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 (reference 4.6-1). The vapour pressure of the test item could not be determined experimentaly using the effusion method (weight loss). The vapour pressure of the test item was below the detection limit of 10^-5hPa. The vapour pressure was calculated using the linear regression equation of the Log P versus 1/T function at 20, 25 and 50 °C. It was calculated to be <9.0E-6 Pa at 20 °C and <1.7E-5 at 25 °C, respectively.