Phthalic acid

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

no data

GLP compliance:

not specified

Type of method:

other: no data

Temp.:

191 °C

Vapour pressure:

7.62 hPa

Reference 2

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

QSAR calculation: detailed information see "any other information on materials and methods" and "any other information on results"

Guideline:

other: REACH guidance on QSARs R.6, May 2008

Principles of method if other than guideline:

The Estimation Program Interface (EPI) Suite v4.11 includes the model MPBPWIN for estimating the vapour pressure of organic compounds. The Estimation Programs Interface was developed by the US Environmental Agency's Office of Pollution Prevention and Toxics and Syracuse Research Corporation (SRC). © 2000 - 2012 U.S. Environmental Protection Agency for EPI SuiteTM. Published online in November 2012.

GLP compliance:

no

Type of method:

other: QSAR

Temp.:

25 °C

Vapour pressure:

0.008 Pa

Remarks on result:

other: modified Grain method

Validity of the model:

1. Defined Endpoint: Vapour pressure

2. Unambigous algorithm: The modified Grain method equation was used for calculation.

3. Applicability domain: Because an experimental boiling and melting point is available for phthalic acid the applicablity domain is just described by the molecular weight range. With a molecular weight of 166.13 g/mol the substance is within the applicable range of 16 - 943 g/mole.

4. Statistical characteristics: Correlation coefficient of the total test set is r²= 0.949.

5. Mechanistic interpretation: The vapour pressure is related to fugacity models describing the distribution of the substance in the environment.

Adequacy of prediction: The result for phthalic acid falls within the applicability domain described above and the estimation rules applied for the substance appears appropriate. Therefore the predicted value can be considered reliable yielding a useful result for further assessment.

Conclusions:

The QSAR determination of the vapour pressure of phthalic acid using the model MPBPWIN included in the Estimation Program Interface (EPI) Suite v4.11 revealed a value of 0.00846 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Executive summary:

The vapour pressure of phthalic acid was predicted using the QSAR calculation of the Estimation Programm Interface EPI-Suite v4.11. The experimental melting point of 191 °C (at 1013 hPa) and boiling point of 289 °C (at 1013 hPa) were taken into account for estimation. Using the modified Grain method, the vapour pressure was estimated to be 0.00846 Pa at 25°C. The predicted value can be considered reliable yielding a useful result for further assessment.

Reference 3

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: original literature not yet available

Principles of method if other than guideline:

no data

GLP compliance:

not specified

Type of method:

other: no data

Temp.:

25 °C

Vapour pressure:

0 hPa

Reference 4

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: abstract

Principles of method if other than guideline:

no data

GLP compliance:

not specified

Type of method:

other: no data

Temp.:

25 °C

Vapour pressure:

0 hPa

The value for 25 °C (298 K) is calculated with the following equation  
(in  appendix C: Coefficients for vapor pressure equation):
log P = A + B/T + C log T + D T + E T² (P - mmHg, T - K),
where A =  -90.3221
B = -3.2214E+3
C =  4.4109E+1
D = -5.0056E-2
E =  1.6895E-5

Description of key information

Using MPBPWIN v1.42 the suggested value of vapour pressure is 1.02 E-6 hPa (Modified Grain Method).

Key value for chemical safety assessment

Vapour pressure:

0 hPa

at the temperature of:

25 °C

Additional information

As key information a calculated value is reported only. As all calculated and literature values are nearly in the same order of magnitude, the literature values were taken into consideration as Weight of Evidence (Yaws 1994, Daubert 1994).