Trifluoromethanesulphonic acid

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 20 July 2012 to 26 September 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7950 (Vapor Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

2010-08-25

Type of method:

dynamic method

Key result

Temp.:

20 °C

Vapour pressure:

2.4 hPa

Key result

Temp.:

25 °C

Vapour pressure:

3.2 hPa

Key result

Temp.:

50 °C

Vapour pressure:

12.9 hPa

Key result

Transition / decomposition:

no

Thermal stability test:

No effects could be observed up to a maximum temperature of 300 °C. From approximately 260 °C up to 300 °C the base line is a bit noisy, which is caused by increasing pressure.

Dynamic method:

The vapour pressure are measured in the temperature range of 78 to 164 °C. The measured vapour pressure values together with the measured temperatures are listed in the following table:

No.	Temperature / °C	Vapour pressure / hPa	Remark
1	78.17	50	measured up
2	96.21	100	measured up
3	115.15	200	measured up
4	126.72	300	measured up
5	135.29	400	measured up
6	157.63	800	measured up
7	163.51	950	measured up
8	155.53	750	measured down
9	142.37	500	measured down
10	121.44	250	measured down

From the measured data points of the vapour pressure curve (vapour pressure in Pa versus inverse temperature in 1/K), the constants A, B and C of the Antoine equation can be derived by regression of the data points to:

A = 10.2626

B = -2311.14

C = 273.15.

Coefficient of determination: R²= 0.9998

The vapour pressure of the test item calculated by extrapolation of the measured vapour pressure curve for the temperatures 20, 25 and 50 °C, according to Regulation EC 440/2008 Method A.4.Vapour Pressure are shown in the following table:

Temperature / °C	Vapour pressure / hPa
20	2.4
25	3.2
50	12.9

Conclusions:

The vapour pressure of the test item at 20°C is 2.4 hPa.
The vapour pressure of the test item at 25°C is 3.2hPa.
The vapour pressure of the test item at 50°C is 12.9 hPa. Based on these results the test item can be considered as low volatile.

Executive summary:

The vapour pressure was carried out using a procedure designed to be compatible with Method A4 Vapour Pressure of Commission Regulation (EC) No 440/2008 of 30 May 2008, Method 104 of the OECD Guidelines for Testing Chemicals and GLP. No deviations from the Guidelines was observed.

Before the determination of the test item vapour pressure, a DSC-measurement was performed to determine the thermal stability of the test item. The test item was stable until 300°C.

Then the vapour pressure test with the dynamic method was performed. The test item is filled in a storage tank, which is at the bottom of the apparatus and it is stirred with a magnetic stirrer. The thermo dynamic equilibrium is reached within a Cottrell pump. The Cottrell pump is located shortly above the liquid level. After the vapour and liquid phase had passed the Cottrell pump, both the liquid and the vapour phase condensate are returned into the storage tank.At equilibrium, the vapour pressure of a pure substance is a function of temperature only (Antoine equation). From the measured data points of the vapour pressure curve (vapour pressure in Pa versus inverse temperature in 1/K), the constants A, B and C of the Antoine equation can be derived by regression. With these constants and the Antoine equation, the vapour pressure of the test item at 20, 25 and 50°C was calculated.

The vapour pressure of the test item at 20°C is 2.4 hPa.

The vapour pressure of the test item at 25°C is 3.2hPa.

The vapour pressure of the test item at 50°C is 12.9 hPa. Based on these results, the test item can be considered as low volatile.

Description of key information

Experimental value of vapour pressure:  2.4 hPa (at 20°C), 3.2 hPa (at 25°C), 12.9 hPa (50°C). Based on these results, the test item can be considered as low  volatile.
Database data: 10 hPa at 50°C (GESTIS), 0.133 hPa at 25°C (SRC)

Key value for chemical safety assessment

Vapour pressure:

2.4 hPa

at the temperature of:

20 °C

Additional information

The key study was carried out using a procedure designed to be compatible with Method A4 Vapour Pressure of Commission Regulation (EC) No 440/2008 of 30 May 2008, Method 104 of the OECD Guidelines for Testing Chemicals and GLP. No deviations from the Guidelines was observed.Before the determination of the test item vapour pressure, a DSC-measurement was performed to determine the thermal stability of the test item. The test item was stable until 300°C.

The key study results for the vapour pressure are 2.4 hPa (at 20°C), 3.2 hPa (at 25°C), 12.9 hPa (50°C). Based on these results, the test item can be considered as low volatile.

The data from the database GESTIS is consistent with this experimental result.

The data from the database SRC was obtained with extrapolated data from various data of unknown origin. This can explain the difference with the result of the key study.