Commiphora myrrha, ext.

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 January 2018 - 19 January 2018

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. The test substance is adequately characterised. Therefore full validation applies.

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

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

Inspected on 20-21 June 2017/ Signed on 04 September 2017

Type of method:

static method

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

950 Pa

Key result

Test no.:

#2

Temp.:

25 °C

Vapour pressure:

1 160 Pa

The vapour pressure was measured in the temperature range of 46 °C to 107 °C. The measured vapour pressures at the corresponding temperatures are listed in Table 1. At 107.1 °C no constant vapour pressure could be measured. Even after > 24 hours the vapour pressure continued to rise and it was concluded that thevapour pressure should only be measured at lower temperatures due to an apparent gas formation of the test item at a temperature of 107 °C.

Table1: Measured vapour pressures and corresponding temperatures

Temperature / °C	Vapour pressure / hPa
46.2	25.6
52.0	30.9
58.1	38.0
66.4	48.0
86.7	88.2
107.1	pnot constant, rises continuously

Then a graph giving the vapour pressure as a function of the inverse temperature (1/T, T in Kelvin) is performed.

The regression curve with slope B and intercept A was calculated. The calculated Antoine constants A, B and C as shown in Table 2.

From these parameters, the values of vapour pressure at 20, 25, and 50 °C were calculated using the following equation:

log (p/hPa) = B/(C+T[°C]) + A

Table2: Antoine parameters and extrapolated vapour pressures

T / °C	p / hPa	log (p/hPa) = A + B/(C+T[°C])
20	9.5	A = 6.17769
25	11.6	B = -1524.05
50	28.9	C = 273.15

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

T / °C	p / hPa	p / Pa
20	9.5	950
25	11.6	1160
50	28.9	2890

Conclusions:

The vapour pressure of the test item was determined as 950 Pa at 20.0 °C and 1160 Pa at 25 °C (interpolation).

Executive summary:

The study was performed in order to determine the vapour pressure of test item according to OCED104, resp. EU A.4 guideline.

The vapour pressure of the test item was determined as 950 Pa at 20.0 °C and 1160 Pa at 25 °C (interpolation).

Description of key information

The vapour pressure of the test item was determined as 950 Pa at 20.0 °C and 1160 Pa at 25 °C (interpolation).

Key value for chemical safety assessment

Vapour pressure:

1 160 Pa

at the temperature of:

25 °C

Additional information

A fully reliable experimental study, conducted according to a recognized OECD/EC method and under GLP, is available. It is considered as a key study.