Dimethoxydimethylsilane

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:

10-Oct-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

1.5.2 Static method

GLP compliance:

no

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

static method

Temp.:

20 °C

Vapour pressure:

86.6 hPa

Temp.:

40 °C

Vapour pressure:

205 hPa

Results

 

Raw data

Data point	Time [min]*	Temperature T [°C]	Vapor pressure p [hPa]
1	15	20	86.0
2	20	25	109.0
3	20	30	136.3
4	20	40	204.4

*  Time for equilibration

 

Conversion of Raw Data

Data point	T [K]	1fT [1/K]	log p [hPa]
1	293.15	0.003411	1.93450
2	298.15	0.003354	2.03743
3	303.15	0.003299	2.13450
4	313.15	0.003193	2.31048

 

Results from Calculation

Estimated vapour pressure	Temperature
86.6 hPa	20°C
205 hPa	40°C

The estimated value is calculated using the formula of regression

 

Formula of regression: log p [hPa] = -1722.81 1/T [1/K] = 7.81418

Conclusions:

Vapour pressure values of 86.6 hPa at 20 °C and 205 hPa at 40 °C was determined in a reliable study conducted according to an appropriate test protocol.

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction

Principles of method if other than guideline:

The result was obtained using an appropriate QSAR method (see attached QMRF and QPRF for details).

GLP compliance:

no

Temp.:

25 °C

Vapour pressure:

7 400 Pa

Conclusions:

A vapour pressure 7400 Pa at 25°C was obtained for the substance using an appropriate calculation method. The result is considered to be reliable.

Reference 3

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Principles of method if other than guideline:

no guideline stated

GLP compliance:

no

Temp.:

20 °C

Vapour pressure:

100 hPa

Conclusions:

A vapour pressure of 100 hPa is reported in secondary literature (company data summary). The original reference was not available for review and no further information is available. The reliability of this result is not assignable.

Description of key information

Parent substance: 86.6 hPa at 20°C, 205 hPa at 40°C (measured)

Key value for chemical safety assessment

Vapour pressure:

86.6 hPa

at the temperature of:

20 °C

Additional information

A measured vapour pressure value of 86.6 hPa at 20°C and 205 hPa at 40°C was determined according to OECD 104 (static method). The results are considered to be reliable. In a supporting study a value of 74.0 hPa at 25°C was determined using an appropriate calculation method (QSAR). The higher value determined for the measured result may due to residual amounts of (more volatile) solvent.

Another measured value of 100 hPa at 20°C is available from a secondary source, but the original reference was not available for review and no information on the method is given, so the reliability of the result is not assignable. A value of 113.68 at 25 °C is reported in the SIDS Initial Assessment Profile for Dimethoxydimethylsilane (2010).