3,3,4,4,5,5,6,6,7,7,8,8-dodecafluorodeca-1,9-diene

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From July 2017 to November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7950 (Vapor Pressure)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: isothermal thermogravimetry

Specific details on test material used for the study:

- Appearance: Clear colourless liquid
- Test item storage: At room temperature protected from light
- Purity/Composition correction factor: No correction factor required

Key result

Temp.:

20 °C

Vapour pressure:

1 200 Pa

Key result

Temp.:

25 °C

Vapour pressure:

1 900 Pa

The vapour pressure regression curve of the log PT of the test item as function of the reciprocal temperatures. The equation of the curve was: log PT = -3344 × 1/T + 14.49 (r = 0.993, n = 8).

Table 1: Results of the Vapour pressure Isothermal TGA Analysis

Temperature [°C]	Weight loss [µg/min]	νT [g/cm2/h]	log νT	log PT	PT [Pa]
27.5	340.300	4.06 x 0.01	-1.39	3.36	2.3 x 1000
	346.036	4.13 x 0.01	-1.38	3.37	2.3 x 1000
30	400.625	4.78 x 0.01	-1.32	3.45	2.8 x 1000
	417.893	4.99 x 0.01	-1.30	3.47	3.0 x 1000
32.5	481.318	5.75 x 0.01	-1.24	3.55	3.5 x 1000
	492.149	5.87 x 0.01	-1.23	3.56	3.6 x 1000
35	569.397	6.80 x 0.01	-1.17	3.64	4.4 x 1000
	543.392	6.49 x 0.01	-1.19	3.62	4.1 x 1000

Table 2: Vapour Pressure of the Test Item

Temperature[°C]	log PT	PT[Pa]	PT [mm Hg]
20	3.08	1200	9.0
25	3.27	1900	14

Conclusions:

The vapour pressure of the test item was determined to be 1200 Pa at 20°C and 1900 Pa at 25°C.

Executive summary:

The vapour pressure of the test item was determined in a GLP-compliant study performed in accordance with EC A.4 method and OECD Guideline No. 104, using the isothermal thermogravimetric (TGA) effusion method.

The vapour pressure of the test item was determined to be 1200 Pa at 20°C and 1900 Pa at 25°C.

Reference 2

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From November 2015 to December 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was well documented and performed according to recognized guidelines. No deviation from the guideline was observed.

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:

not specified

Type of method:

static method

Temp.:

20.03 °C

Vapour pressure:

10.647 mBar

Remarks on result:

other: Mean of 3 measurements

Temp.:

25.36 °C

Vapour pressure:

12.468 mBar

Remarks on result:

other: Mean of 3 measurements

Temp.:

30.76 °C

Vapour pressure:

14.672 mBar

Remarks on result:

other: Mean of 3 measurements

Temp.:

39.95 °C

Vapour pressure:

18.833 mBar

Remarks on result:

other: Mean of 3 measurements

Temp.:

49.37 °C

Vapour pressure:

24.234 mBar

Remarks on result:

other: Mean of 3 measurements

Transition / decomposition:

no

The uncertainty of measurement for pressure is about 0.8 mbar and 0.05°C for the temperature.

The value obtained between 20.03 to 49.37°C are used to regress the coefficient of Antoine's law using the following equation:

Ln P = A + [ B / (T +C) ]

With P in mbar and T in K

The error involved by the modeling of vapor pressure with the determined Antoine's law is about 0.1 mbar which is in magnitude of the uncertainty of measurement of pressure (0.8 mbar).

The calculated vapor pressure values (with Antoine's law coefficient) are compared to the experimental data obtained during the study.

The results are shown in the table below.

Temperature (°C)	Vapor pressure measured Pexp (mbar)	Vapor pressure calculated Pcalc (mbar)	Pexp-Pcal (mbar)
20.03	10.647	10.65	0.01
25.36	12.468	12.49	0.02
30.76	14.672	14.61	0.06
39.95	18.833	18.88	0.04
49.37	24.234	24.22	0.01

The experimental and the calculated vapor pressures are consistent between them.

Conclusions:

The vapor pressure of the test item is measured at 10.647 mbar at 20°C and 12.468 mbar at 25°C.

Executive summary:

The vapor pressure was determined with the static method according to recognized guidelines (EU A.4 Method and OECD 104 Guideline). No deviation from the guideline was observed during the study.

With this process, at thermodynamic equilibrium, the vapor pressure established in a closed system is determined at a specified temperature. The sample was degassed at 20°C before measurement of the vapor pressure.

The vapor pressure was measured at 10.647 mbar at 20°C and 12.468 mbar at 25°C.

Description of key information

The vapour pressure of the test item was determined in a GLP-compliant study performed in accordance with EC A.4 method and OECD Guideline No. 104, using the isothermal thermogravimetric (TGA) effusion method. The vapour pressure of the test item was determined to be 1200 Pa at 20°C and 1900 Pa at 25°C.

These experimental values are further supported by a non-GLP study, performed according to the same recognized guideline than in the key study (OECD 104) and reporting a vapour pressure of 1065 Pa at 20°C.

In a disregarded study, the vapor pressure was estimated to be 216 Pa at 25°C. This data was obtained by extrapolation of data obtained at highest temperature (96 to 120°C approximately)

Key value for chemical safety assessment

Vapour pressure:

1 200 Pa

at the temperature of:

20 °C

Additional information

The vapour pressure of the test item was investigated in a GLP-compliant study performed in accordance with standard methods, without deviations. The study is considered as reliable (Klimisch 1) and is selected as a key study for the endpoint. A non-GLP study is also reported for the endpoint and selected as supporting study (Klimisch 1).

In the disregarded study, the vapor pressure at 25°C was obtained by extrapolation of plots relating the logarithm of Vapor pressure (in Pa) and the inverse of the temperature (in K). These plots were built using vapor pressure measured at high temperatures. It is specified in international recognized guidelines (EU A.4 Method and OECD 104 guideline), that the relation between the vapor pressure and the inverse of the temperature is a linear function only on a limited range of temperature.

We have checked the validity of plots extrapolation by calculating the vapor pressure at 135°C (which is the boiling temperature of the test item). Indeed, the plots have been determined with data obtained at temperatures closed to the boiling point. Based on recognized guidelines (OECD 103 guideline and EU A.2 Method), we know that the vapor pressure of a substance is equal to the atmospheric pressure (101,325 kPa) at the boiling temperature.

So we calculated (with the equation obtained at each run) the vapor pressure at 135°C. The values obtained with the 3 equations are not consistent with the expected vapor pressure value at the boiling point. In a temperature range near to the temperatures used to obtain the plots (relating vapor pressure and temperature), the extrapolated vapor pressure is very different from the expected value.

We can conclude that the extrapolation at temperature far from the one used for the plots will give more irrelevant results and therefore the extrapolated values are considered unreliable.

As a confirmation, the extrapolation at 25°C of the vapor pressure using the equation obtained from the 3 experimental runs is inconsistent with the experimental vapour pressure values obstained in the key and supporting studies.

Because of the above the study was disregarded.