1,4-naphthoquinone

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017

Reliability:

2 (reliable with restrictions)

Justification for type of information:

For solids, the default subcooled vapor pressure calculated by MPBPWIN is the Modified Grain method value (the portion of the equation that calculates the liquid vapor pressure before conversion to a solid-phase vapor pressure).

Qualifier:

according to guideline

Guideline:

other: Guidance on information requirements and chemical safety assessment, Chapter R.6: QSARs and grouping of chemicals, ECHA, May 2008

Principles of method if other than guideline:

MPBPWIN estimates vapor pressure (VP) by three separate methods: (1) the Antoine method, (2) the modified Grain method, and (3) the Mackay method. All three use the normal boiling point to estimate VP. Unless the user enters a boiling point on the data entry screen, MPBPWIN uses the estimated boiling point from the adapted Stein and Brown method.

GLP compliance:

no

Type of method:

other: Calculation

Temp.:

25 °C

Vapour pressure:

ca. 0.025 Pa

Remarks on result:

other: QSAR predicted value

Remarks:

Modified Grain method

The accuracy of MPBPWIN's "suggested" VP estimate was tested on a dataset of 3037 compounds with known, experimental VP values between 15 and 30 deg C (the vast majority at 25 or 20 deg C).  The experimental values were taken from the PHYSPROP Database that is part of the EPI Suite.  For this test, the CAS numbers were run through MPBPWIN as a standard batch-mode run (using the default VP estimation temperature of 25 deg C) and the batch estimates were compared to PHYSPROP's experimental VP.

The 3037 compound test set contains 1642 compounds with available experimental Boiling points and Melting points ... For this subset of compounds, the estimation accuracy statistics are (based on log VP):

 number = 1642

  r²= 0.949

  std deviation = 0.59

  avg deviation = 0.32

These statistics clearly indicate that VP estimates are more accurate with experimental BP and MP data.

Executive summary:

The vapour pressure of 1,4-naphthoquinone was predicted by MPBPWIN to be 0.0246 Pa.

Key value for chemical safety assessment

Vapour pressure:

0.025 Pa

at the temperature of:

25 °C

Additional information

The vapour pressure of 1,4-naphthoquinone was calculated to be 0.0246 Pa ( Modified Grain method).