Dichloromethylbenzene

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Principles of method if other than guideline:

Experimental determination of the vapour pressure was carried out for temperatures > 60 °C. Based on the obtained data, the vapour pressure values at 20 °C, 25 °C and 50 °C were calculated using the Antoine equation.

GLP compliance:

yes (incl. QA statement)

Type of method:

dynamic method

Temp.:

20 °C

Vapour pressure:

< 1 hPa

Remarks on result:

other: calculated with the Antoine equation, precise value is calculated to be 45 Pa

Temp.:

25 °C

Vapour pressure:

< 1 hPa

Remarks on result:

other: calculated with the Antoine equation, precise value is calculated to be 65.3 Pa

Temp.:

50 °C

Vapour pressure:

3 hPa

Remarks on result:

other: calculated with the Antoine equation, precise value is calculated to be 338 Pa

The vapour pressure is measured in the temperature range of 69.8 - 199.4 °C and displayed as a vapour pressure curve. The experimentally determined values are listed below:

U in mV	T in °C	P in hPa
69.2	69.8	9.7
83.6	84.3	21.1
120.4	121.4	99.2
164.7	166.0	421
197.7	199.3	1017.4
97.2	98.0	38.8
150.4	151.6	266
182.3	183.8	682.5
197.8	199.4	1016

The values for the vapour pressure at lower temperatures, i. e. at 20 °C, 25 °C and 50 °C are calculated from the experimentally determined ones with the Antoine equation as follows:

Antoine equation: P = 10^{(A-(B/[T+C]))}

with A = 7.4395; B = 1842.1; C = 216.59; T = Temperature in °C; p = vapour pressure in hPa

The results are for T = 20 °C, p = 45 Pa; T = 25 °C, p = 65.3 Pa; T = 50 °C, p = 338 Pa, although in the report it is summarized, that

p < 1 hPa for 20 °C and 25 °C as well as p = 3 hPa at 50 °C

Conclusions:

The vapour pressure was determined to be <1 hPa at 20 °C and at 25 °C.

Executive summary:

The vapour pressure of the DCT mixture was experimentally determined for temperatures > 60 °C according to EC method A.4 under GLP and calculated for 20 °C, 25 °C and 50 °C based on the experimental data. The vapour pressure at 20 °C is calculated to be 45 Pa, at 25 °C to be 65.3 Pa (both corresponding to < 1 hPa) and to be 338 Pa at 50 °C (roughly corresponding to 3 hPa).

Description of key information

The vapour pressure of the DCT mixture was determined experimentally according to EC method A.4 under GLP (Treckmann, 1993) at elevated temperatures, i.e. at > 60 °C. 
For 20 °C , 25 °C and 50 °C, the vapour pressure values were deduced from the experimental determined ones (Treckmann, 1993) by calculation using the Antoine equation. The calculated values are 45 Pa at 20 °C, 65.3 Pa at 25 °C and 338 Pa at 50 °C, respectively. The values at 20 °C and 25 °C are in line with the vapour pressure values for the individual DCT isomers that lie in the range of 30.7 - 61.06 Pa at 20 °C and 25 °C as reported in various reliable data sources (ChemIDplus, 2009; Ullmann, 2006; EPIWIN, 2009). Hence the vapour pressure of 65.3 Pa at 25 °C was selected as key value.

Key value for chemical safety assessment

Vapour pressure:

65.3 Pa

at the temperature of:

25 °C