Xylene

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:

1949-1954

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status not known, information from a published handbook, acceptable with restrictions.

Principles of method if other than guideline:

The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to the Handbook of Vapor Pressures and Heats of Vapourization of Hydrocarbons and Related Compounds states that data included has been collected, calculated, critically selected and compiled. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.

GLP compliance:

not specified

Type of method:

other: not reported

Specific details on test material used for the study:

N/A

Key result

Temp.:

80 °F

Vapour pressure:

0.202 PSI

This handbook reports vapour pressures for ethylbenzene from 80˚F to 330˚F together with the Antoine equation constants to allow vapour pressures at other temperatures to be calculated. For ethylbenzene the constants are A = 5.24358, B = 2563.659, C = 351.771 and t = temperature in Fahrenheit. The Antoine equation is log P = A - (B/(C+t)). The vapour pressure at 20˚C (68°F) is therefore 0.1369 PSI. The vapour pressure at 25˚C (77 F) is 0.18386 PSI (1.2677 kPa)

Conclusions:

The reported vapour pressure of ethylbenzene at 80˚F (26.6˚C) is 0.202 PSI. This is the lowest reported temperature at which vapour pressure is reported as Zwolinski and Wilhoit (1971) use a cut-off of 0.2PSI in their data tables. However, the handbook also provides the Antoine constants to allow vapour pressures at other temperatures to be calculated. The vapour pressure of ethylbenzene at 20˚C is calculated to be 0.1369 PSI (0.944 kPa). Although we have extrapolated outside the reported temperature range to derive this value we believe that the calculated value is an acceptable estimate of the vapour pressure at 20˚C as the state of the substance will not change in this temperature range (melting point -94.96˚C).

Executive summary:

This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use for this endpoint.

Reference 2

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1949-1954

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status not known, information from a published handbook, acceptable with restrictions.

Principles of method if other than guideline:

The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to the Handbook of Vapor Pressures and Heats of Vapourization of Hydrocarbons and Related Compounds states that data included has been collected, calculated, critically selected and compiled. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.

GLP compliance:

not specified

Type of method:

other: not reported

Specific details on test material used for the study:

N/A

Key result

Temp.:

85 °F

Vapour pressure:

0.207 PSI

This handbook reports vapour pressures for m-xylene from 85˚F to 330˚F together with the Antoine equation constants to allow vapour pressures at other temperatures to be calculated. For m-xylene the constants are A = 5.29547, B = 2632.079, C = 355.189 and t = temperature in Fahrenheit. The Antoine equation is log P = A - (B/(C+t). The vapour pressure at 25˚C is therefore 0.160457 PSI or 11.06 hPa.

Conclusions:

The reported vapour pressure of m-xylene at 85˚F (29.4˚C) is 0.207 PSI. This is the lowest reported temperature as Zwolinski and Wilhoit (1971) use a cut-off of 0.2 PSI in their data tables. However, the handbook also provides the Antoine constants to allow vapour pressures at other temperatures to be calculated. The vapour pressure of m-xylene at 25˚C is calculated to be 0.160457 PSI (11.06 hPa). Although we have extrapolated outside the reported temperature range to derive this value we believe that the calculated value is an acceptable estimate of the vapour pressure at 25˚C as the state of the substance will not change in this temperature range (melting point -47.8˚C).

Executive summary:

This information is taken from a reliable peer reviewed handbook and can be considered reliable and suitable for use as the key study for this endpoint.

Reference 3

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1949-1952

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status not known, guideline not known study, information from published handbook, acceptable with restrictions

Principles of method if other than guideline:

The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to the Handbook of Vapor Pressures and Heats of Vapourization of Hydrocarbons and Related Compounds states that data included has been collected, calculated, critically selected and compiled. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.

GLP compliance:

not specified

Type of method:

other: not reported

Specific details on test material used for the study:

N/A

Key result

Temp.:

90 °F

Vapour pressure:

0.194 PSI

Remarks on result:

other: Lowest temperature reported in handbook as a cut off of 0.2 PSI was used.

This handbook reports vapour pressures for o-xylene from 90˚F to 340˚F together with the Antoine equation constants to allow vapour pressures at other temperatures to be calculated. For o-xylene the constants are A = 5.28530, B = 2654.422, C = 352.635 and t = temperature in Fahrenheit. The Antoine equation is log P = A - (B/(C+t). The vapour pressure at 25˚C is therefore 0.1279 PSI or 8.82hPa.

Conclusions:

The reported vapour pressure of o-xylene at 90˚F (32.2˚C) is 0.194 PSI. This is the lowest reported temperature as Zwolinski and Wilhoit (1971) use a cut-off of 0.2 PSI in their data tables. However, the handbook also provides the Antoine constants to allow vapour pressures at other temperatures to be calculated. The vapour pressure of o-xylene at 25˚C is calculated to be 0.128 PSI (8.82 hPa). Although we have extrapolated outside the reported temperature range to derive this value we believe that the calculated value is an acceptable estimate of the vapour pressure at 25˚C as the state of the substance will not change in this temperature range (melting point -25.2˚C).

Executive summary:

This information is taken from a reliable peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint.

Reference 4

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1971

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status not known, information from a published handbook, acceptable with restrictions.

Principles of method if other than guideline:

The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to the Handbook of Vapor Pressures and Heats of Vapourization of Hydrocarbons and Related Compounds states that data included has been collected, calculated, critically selected and compiled. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.

GLP compliance:

not specified

Type of method:

other: not reported

Specific details on test material used for the study:

N/A

Key result

Temp.:

80 °F

Vapour pressure:

0.186 PSI

This handbook reports vapour pressures for p-xylene from 80˚F to 330˚F together with the Antoine equation constants to allow vapour pressures at other temperatures to be calculated. For p-xylene the constants are A = 5.27691, B = 2616.174, C = 355.553 and t = temperature in Fahrenheit. The Antoine equation is log P = A - (B/(C+t). The vapour pressure at 25˚C is therefore 0.169314 PSI or 11.674hPa.

Conclusions:

The reported vapour pressure of p-xylene at 80˚F (26.6˚C) is 0.186 PSI. This is the lowest reported temperature as Zwolinski and Wilhoit (1971) use a cut-off of 0.2 PSI in their data tables. However, the handbook also provides the Antoine constants to allow vapour pressures at other temperatures to be calculated. The vapour pressure of p-xylene at 25˚C is calculated to be 0.169314 PSI (11.674 hPa). Although we have extrapolated outside the reported temperature range to derive this value we believe that the calculated value is an acceptable estimate of the vapour pressure at 25˚C as the state of the substance will not change in this temperature range (melting point 13.2˚C).

Executive summary:

This information is taken from a reliable peer reviewed handbook and can be considered reliable and suitable for use as the key study for this endpoint.

Description of key information

The reported vapour pressure of the xylene isomers at 25˚C ranges from 0.882 to 1.2677kPa. The vapour pressure of Ethylbenzene was reported at 20˚C, the value of the vapour pression at 25˚C, using the Antoine equation is log P = A - (B/(C+t)), was reported to be 1.2677 kPa, for m-xylene is 1.106 kPa, for o-xylene is 0.882 kPa and for p-xylene is 1.167 kPa. The mean value of 1.105675 kPa was used in this assessment.

Key value for chemical safety assessment

Vapour pressure:

1.106 kPa

at the temperature of:

25 °C

Additional information

Data was taken from Zwolinski and Wilhoit (1971) which is a peer reviewed handbook and so can be considered reliable and suitable for use as the key study for this endpoint. The data are supported by results from the CRC Handbook (Lide 2008), with vapour pressures for m-xylene, o-xylene, p-xylene and ethylbenzene of 1 kPa at 23.4˚C, 1 kPa at 27°C, 1 kPa at 22.4°C and 1 kPa at 21.1°C respectively.