(E)-4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (stabilized with BHT)

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:

17-18 Jan. 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. The substance is adequately characterised with its purity. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

March 23, 2006

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

Directive 92/69/EEC

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate from 2007-05-16

Type of method:

static method

Key result

Temp.:

20 °C

Vapour pressure:

302 Pa

Two series of 12 values were recorded (detailed results in experimental report).

The test substance was considered to show ideal behaviour. Using the linear relationship between 1/T and log VP, the vapour pressure at 20°C was determined by regression analysis. The curves were derived by using a least squares method to calculate a straight line that best fits the measured data (Clapeyron).

The coefficient of correlation (r) was > 0.99.

Extrapolation of the curve of the test substance to 20°C was 302 Pa.

Conclusions:

Low volatility (based on volatility bands criteria for occupational exposure (Chesar / ECETOC TRA), < 500 Pa).

Executive summary:

The vapour pressure of the test substance was measured, under GLP, according to OECD 104 / EU A.4 guidelines, static method. Two runs were performed, with 12 measurements recorded between 45 and 100°C. The linear regression log VP = f(T) was derived, and vapour pressure at 20°C was extrapolated from the equation as 302 Pa.

Reference 2

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

30 May - 28 June 2005

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. However, the test item identification is incomplete (unspecified cis-trans isomery, therefore identified under the generic CAS 17129-06-5). Therefore validation applies with restrictions.

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

Directive 92/69/EEC

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate from 2004-12-22

Type of method:

static method

Temp.:

20 °C

Vapour pressure:

265 Pa

Temperature (°C)	30.7	37.1	42.2	46.1	50.5
Vapour pressure after corrections (Pa)	569.8	842.1	1144.8	1568.0	1951.3

The corrected vapour pressure are plotted in a Clausius-Clapeyron plot. Regression through all data points yields:

log VP [Pa] = -6.2325 * 1/T*1000 (K) + 26.84

R² = 0.9974

Extrapolation using this regression function yields an estimated vapour pressure of 265 Pa at 20°C and 379 Pa at 25°C.

Executive summary:

The vapour pressure of the test substance was measured, under GLP, according to EU A.4 guideline, static method. One run was performed, with 5 measurements recorded between 30 and 50°C. The linear regression log VP = f(T) was derived, and vapour pressure at 20°C was extrapolated from the equation as 265 Pa.

Reference 3

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

29 Aug. to 03 Sept. 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. However, the method used was not suitable for the magnitude of order of the vapour pressure of the test substance, according to guideline recommendations. But internal validation was extended to cover actual measurements. The substance is adequately characterised with its purity.Therefore validation applies with restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

March 23, 2006

Deviations:

yes

Remarks:

recommended measuring range

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

Directive 92/69/EEC

Deviations:

yes

Remarks:

recommended measuring range

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate from 2007-05-16

Type of method:

effusion method: isothermal thermogravimetry

Temp.:

20 °C

Vapour pressure:

465 Pa

Reference substances

Regression curve: log P,20 = 1.12 x log V,20 + 4.86 (r=0.997, n=14)

where:

P,20: vapour pressure at 20°C (Pa)

V,20: evaporation rate at 20°C (g/cm²/h)

Test substance

Experiment No. (at 20°C)	Weight loss (µg/min)	V,20 (g/cm^2/h)	log P,20
1	135.3	1.62 E-2	-1.79
2	130.6	1.56 E-2	-1.81
3	131.5	1.57 E-2	-1.80
		Average log P,20	-1.80

Fitting the average log P,20 value in the regression curve, a vapour pressure of 4.65 E2 Pa was obtained.

Executive summary:

The vapour pressure of the test substance was measured, under GLP, according to OECD 104 / EU A.4 guidelines, isothermal thermogravimetric method. The system was calibrated with seven reference substances, with VP between 1 .33 E-8 and 2.34 E+3 Pa at 20°C, as a linear regression. Three measurements were recorded at 20°C. The vapour pressure was interpolated from the equation as 465 Pa.

Description of key information

Low volatility at ambient temperature.

Key value for chemical safety assessment

Vapour pressure:

302 Pa

at the temperature of:

20 °C

Additional information

Three experimental studies are available; all were conducted according to OECD/EU guideline and GLP, and give quite consistent results:

- The static method, presented in Notox 2008 report, was considered to be the most suitable, considering the magnitude of order measured, and extrapolation from the working range was limited. Therefore it was considered as fully reliable, key study, and the result of 302 Pa at 20°C is retained as key data.

- In TNO 2005 report, the static method was also used, but the study was assigned lower reliability, due to incomplete test item identification (i.e. unspecified cis-trans isomery). The working temperature range was also smaller than above, so considered of lower quality for the regression, though extrapolation was even closer. Thus it is included as supporting data. The result (265 Pa at 20°C) is very consistent with the key value.

- An effusion method was used in Notox 2007 report, which is not recommended to measure vapour pressures above 1 Pa. However, the laboratory obtained reliable results for more volatile reference substances. Moreover, measurement was conducted for a single temperature, which is a deviation from the guideline, but no extrapolation was needed then. Finally, the result for the test item, 465 Pa at 20°C, is not that far from above, so this study was also included as supporting data.